Author Topic: Resize a STL File For Me  (Read 49254 times)

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Offline bostonmanTopic starter

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Resize a STL File For Me
« on: January 18, 2024, 05:02:19 am »
I am in need of a rotary knob with a 6mm D shaft.

I found one on Thingiverse, however, the diameter and height is too big. To confirm whether the style was correct, earlier I printed the one in the attached file, and, as expected, it's too large (it covers writing on the front panel).

My slicing software allows me to scale it, however, it also scales the D shaft hole.

Attached is the zip file from Thingiverse.

Does anyone have software that will scale it without affecting the center shaft hole size?

It needs to be approx. 13mm height, 18mm diameter at the inside end, 17mm at the outside end, and the inside needs to be 3.15mm hollow before the D part of the hole starts (if this makes sense).

Trying to tweak the hole for the shaft may not be feasible, but thought to throw out that size too.

This knob is for an adjustable power supply. The knob broke and was thrown out by someone. If the knob is too large in diameter, it covers writing on the front panel. If the shaft is too deep, then the button can't be pressed (it rotates and also has a on/off press function). I thought to try making one myself on SketchUp, but I wouldn't know how to create the side notches.

 

Offline Jeroen3

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Re: Resize a STL File For Me
« Reply #1 on: January 18, 2024, 06:51:30 am »
Editing STL with many faces like this is complicated. If you can't scale it in the slicer (eg: prusaslicer can scale on separate axis) then you may be better of searching for a parametric knob.

eg:
https://www.printables.com/model/708831-rotary-encoder-knob-and-button-parametric
https://www.printables.com/model/278448-fully-parametric-knob-freecad
https://www.printables.com/model/281352-parametric-lcd-knob

Or maybe there are some Blender wizards here on the forum?
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #2 on: January 18, 2024, 03:41:52 pm »
I assumed scaling it would be difficult. If not for the hollow d shaft, I could have scaled this easier.

Maybe the links you provided have the correct size; let me check later.
 

Online themadhippy

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Re: Resize a STL File For Me
« Reply #3 on: January 18, 2024, 04:02:05 pm »
Quote
I thought to try making one myself on SketchUp, but I wouldn't know how to create the side notches.
sketch up tends to get  things reversed,something to with it modeling faces,not a solid object.On shape is my weapon of choice ,although tinker cad might be an easier option.What id do is double check the d slot size,re scale the model  and then make the d slot the size you want.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #4 on: January 18, 2024, 04:33:50 pm »
Unfortunately I don't exactly have access to a system that allows newer software to work. My old computer still runs XP (long story, but I have lots of expensive software that is costly to update onto a new system and is too old to use with modern revisions of the software), my other is a 32-bit laptop that runs Ubuntu, and normally I use my work laptop that blocks installing software and/or using online sites such as 3D modeling.

The one I've used is SketchUp online (works with Ubuntu 32-bit), and I think it is horrible, however, it has allowed me to make a few designs. Sadly, errors don't show until I generate a STL file and place it in slicing software. At that point blank areas show and will make me realize lots of time was wasted.

If not for the lines on the side of the knob, and wanting it tapered (although I can live with it being cylindrical), I'd design it myself in SketchUp.
 

Online themadhippy

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Re: Resize a STL File For Me
« Reply #5 on: January 18, 2024, 05:04:23 pm »
this any use as a starting point,no d slot yet as i dont have the dimensions and didnt want to assume.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #6 on: January 18, 2024, 05:52:32 pm »
Quote
It needs to be approx. 13mm height, 18mm diameter at the inside end, 17mm at the outside end, and the inside needs to be 3.15mm hollow before the D part of the hole starts (if this makes sense).

I included the dimensions in my initial message. It doesn't need a line indicator as this knob just spins 360 degrees with the readout on the display.

With the little 3D stuff I've done, I'm curious how one does the lines (?) on the side of the knob. My thought was inserting half circles one at a time, but it seemed to time consuming to be the correct answer.
 

Online themadhippy

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Re: Resize a STL File For Me
« Reply #7 on: January 18, 2024, 06:10:37 pm »
Quote
I included the dimensions in my initial message
but not that of the d shaped cut out,1 size dont fit all.

Quote
, I'm curious how one does the lines (?) on the side of the knob
one my model i drew the base shape  ,then the top circle and used the loft command.That was in onshape.
 

Online Ian.M

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Re: Resize a STL File For Me
« Reply #8 on: January 18, 2024, 06:11:38 pm »
These measurements taken from the O.P's original STL, imported at unit 1mm,  may help:
Code: [Select]
stl_h=15.0; // orig. height
stl_d1=22.1; // orig. top dia. (ignoring rounded top edge)
stl_d2=24.6; // orig. base dia.
stl_fr_h=7.0; // orig. inner cone height (to D shaft)
stl_fr_d1=6.13; // orig. inner cone top dia. (at D shaft)
stl_fr_d2=20.2; // orig. inner cone base dia.
stl_shaft_d=stl_fr_d1; // orig D shaft dia
stl_shaft_l=7.15; // orig D shaft length, from cone top
stl_shaft_f=4.8; // orig D shaft thickness at flat
The knob was rotated flat, wide end down before measuring, and was found to be off-center by approx. 0.06mm in X and 0.03mm in Y.

N.B. the O.P. *will* need to tweak the D shaft diameter and thickness at flat for a good fit, as 3D printer's slicer parameters are rarely tuned well enough to produce accurate holes at nominal diameter, without shrinkage.  Its *HARD* to tune the slicer for accurate holes as the shrinkage varies significantly with inner wall curvature, layer height and flow, and filament used.
« Last Edit: January 18, 2024, 06:19:44 pm by Ian.M »
 

Online Kean

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Re: Resize a STL File For Me
« Reply #9 on: January 18, 2024, 06:12:18 pm »
If I import that model into F360, it is huge - nearly 250mm diameter.  Stupid imperial units...

What I would do is to import it into a 3D modelling tool (Fusion 360 typically), convert to a solid model, scale it to required size, add a central axis, and then make an extruded cut sized to the D shaft.  If I was enlarging it, I'd add extra material.

Even better, I would contact the original designer to ask if they have the original 3D CAD file.  Working with STL files, even if converted to a solid model, is an awful experience.

Anyway, I did basically what I described above.  Scaled all to a ratio of 18/250, then measured height at 10.2mm so I scaled in just the Y direction to a ratio of 13/10.2.   Draw a bounding circle to get an approximate centre, and then drew the D shaft hole.  I sized that for a 6.35mm shaft, with the D based on the same ratio as the original.  Not sure if that is correct for you, but see attached - should be a quick print to test.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #10 on: January 18, 2024, 06:13:03 pm »
Okay
Took a little to cut the scallops.
Not sure of the D-shaft dimensions.

1984765-0

D-cut is 6mm dia with a 3mm wide flat

Edit:  Updated shaft size.  (approx 3.3mm flat)
« Last Edit: January 18, 2024, 06:55:34 pm by MarkF »
 

Online Kean

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Re: Resize a STL File For Me
« Reply #11 on: January 18, 2024, 06:15:00 pm »
With the little 3D stuff I've done, I'm curious how one does the lines (?) on the side of the knob. My thought was inserting half circles one at a time, but it seemed to time consuming to be the correct answer.

Depends on the 3D modelling tool, but in Solidworks or F360 you would draw one of the scallops and then do a circular pattern to repeat it.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #12 on: January 18, 2024, 06:20:23 pm »
I used FreeCAD to make a smooth knob (blue) and then created an array of half cylinders (pink).
Finally cut the knob body with the array body.


 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #13 on: January 18, 2024, 06:21:40 pm »
Quote
Even better, I would contact the original designer to ask if they have the original 3D CAD file.  Working with STL files, even if converted to a solid model, is an awful experience.

I tried this already, but the person didn't respond.

You're correct, I forgot to include the shaft dimension. It's a 6mm D shaft.

I can take pictures of the good knob tonight and post it.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #14 on: January 18, 2024, 06:31:51 pm »
I updated previous knob002.zip with new shaft size based on a Google search.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #15 on: January 18, 2024, 06:36:02 pm »
Just an FYI, I've searched many sites for this knob. In a parallel method, I contacted the power supply company (located in China). They can sell replacement parts, however, shipping will be $50 (not including the cost for the parts), so I resorted to searching Thingiverse for a 3D model.

This knob appears to be a custom design/size as most knobs this small are a different shape, have an indicator line, etc...
 

Online themadhippy

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Re: Resize a STL File For Me
« Reply #16 on: January 18, 2024, 06:36:22 pm »
6x4.5D cutout added
« Last Edit: January 18, 2024, 06:58:40 pm by themadhippy »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #17 on: January 18, 2024, 06:46:45 pm »
Wow..... thanks.

I don't have the ability to look (or print) it now, but I'll look tonight and try printing this weekend.

The experimental oversized one I printed wasn't very tight on the shaft. Most likely it's my printer, and I can get around this by placing some glue on it. Worst case, if I ever need to remove it, I'll need to cut it, but replacing the rotary encoder isn't difficult. If it gets to the point the knobs need to be removed, then it would mean something is wrong anyway.

Also, another option is I can just scale this model (assuming it works) by an extremely small percentage to reduce the shaft hole.
 

Online themadhippy

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Re: Resize a STL File For Me
« Reply #18 on: January 18, 2024, 06:58:05 pm »
forget my last post,heres the correct version
 

Online Ian.M

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Re: Resize a STL File For Me
« Reply #19 on: January 18, 2024, 07:39:12 pm »
@bostonman

I have managed to rescale your original knob STL using OpenSCAD, filling it in then recutting the interior features to size.   Probably the ugliest part was deriving parameters for the original knob, which was done experimentally and iteratively.

To improve it I'd need actual shaft length from panel (less clearance under knob), actual thickness on flat of D shaft, and desired shaft hole clearance.

Hopefully your laptop has a recent enough Debian to allow you to install OpenSCAD by:
Code: [Select]
sudo apt-get install openscadso you can easily tweak the shaft (and other knob) parameters yourself.

OpenSCAD is basically CAD for programmers.  Here's the script, in all its uglyness:
Code: [Select]
// Fixing up a STL file for EEVblog u:bostonman
// ref: [url]https://www.eevblog.com/forum/3d-printing/resize-a-stl-file-for-me/[/url]

/* [New Knob] */
knob_h=13;
knob_d=18;
shaft_d=6.0;
shaft_f=4.8; // ***best guess***
shaft_l=12; //from knob base, ***best guess***
recess_d1=shaft_d; // recess top dia - make bigger than shaft if flat step wanted
recess_d2=14; // recess base dia
recess_h=3.15;

/* [rendering] */
fill_overlap=0.05; // to guarantee solid
slop=0.1; // increase critical hole diameters by this to print to size
$dd=1e-3; // tolerance for face alignment
$fn=120; // circle rendering facets

/* [Orig. STL] */
stl_h=15.0; // orig. height
stl_d1=22.1; // orig. top dia. (ignoring rounded top edge)
stl_d2=24.6; // orig. base dia.
stl_fr_h=7.0; // orig. inner cone height
stl_fr_d1=6.13; // orig. inner cone top dia. (at D shaft)
stl_fr_d2=20.2; // orig. inner cone base dia.
stl_shaft_d=stl_fr_d1; // orig D shaft dia
stl_shaft_l=7.15; // orig D shaft length, from cone top
stl_shaft_f=4.8; // orig D shaft thickness at flat

// //tweak parametrics to fit the origanal knob
//# cylinder(h=stl_h, d1=stl_d1, d2=stl_d2); // bounding conical frustrum
//# translate([0,0,stl_h-stl_fr_h]) cylinder(h=stl_fr_h,d1=stl_fr_d1,d2=stl_fr_d2); //inner cone
//#translate([0,0,stl_h-stl_fr_h-stl_shaft_l]) dshaft(stl_shaft_l,stl_shaft_d,stl_shaft_f); // d shaft

module dshaft(l,d,f){ //l=length, d=dia, f=thickness at flat
    intersection(){
        cylinder(h=l,d=d);
        translate([0,f-d,l/2]) cube([d,d,l],center=true);
    }
}

module knob_shell(h,d){
    scale([d/stl_d2,d/stl_d2,h/stl_h]){
        translate([0.06,0.03,0]) // it was off-center!
            rotate([90,0,0])
            import("Knob_D_shape_rotary_encoder.stl", convexity=3);
        translate([0,0,stl_h-stl_fr_h-stl_shaft_l-fill_overlap])
            cylinder(h=stl_fr_h+stl_shaft_l+fill_overlap,d1=stl_fr_d1+2*fill_overlap,d2=stl_fr_d2+2*fill_overlap); // infill
    }
}

// render the resized knob
//render()  // only needed (for preview) if graphics driver OpenGL is broken!
difference(){
    knob_shell(knob_h,knob_d); // main object
    // --- cuts ---
    translate([0,0,knob_h-recess_h+$dd])
            cylinder(h=recess_h+$dd, d1=recess_d1, d2=recess_d2); // cone
    translate([0,0,knob_h-shaft_l+$dd])
        dshaft(shaft_l+$dd,shaft_d+slop,shaft_f+slop*shaft_f/shaft_d);
}
[code]
 
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Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #20 on: January 19, 2024, 03:08:18 am »
Quote
forget my last post,heres the correct version

I looked at the design and it looks great. I'll try printing it along with the modified one Ian.M posted and see which one is ideal.

Attached is a picture of the good knob.

Update: I'm guessing the 'V' shape hole is a way of getting it to lock onto the shaft. As previously mentioned, I don't really care about this as I'll just glue it. Seeing as how difficult it's been to locate a similar knob, I'm just happy to (hopefully) have a replacement.

« Last Edit: January 19, 2024, 03:29:20 am by bostonman »
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #21 on: January 19, 2024, 03:54:04 pm »
Not exact.   Close.

1985590-0
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #22 on: January 20, 2024, 03:58:40 am »
I only printed knobd2 so far. It’s basically a perfect diameter, height, etc… but doesn’t fit on the shaft.

If anything, the diameter is slightly smaller, so the X-Y ratio can be increased at my end in the slicing software; maybe by 0.5%. This would benefit the shaft hole.

I’ll work on printing the others this weekend. As for knobd2, besides the shaft hole, the lines on the side could be deeper. This may all be due to my printer having poor resolution, but attached is a comparison.

 

Online Ian.M

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Re: Resize a STL File For Me
« Reply #23 on: January 20, 2024, 04:48:01 am »
Do you have a micrometer, digital or Vernier callipers or other means of measuring small objects accurately? If so it would be worth measuring the shaft diameter, and thickness on the flat before printing more knobs and posting the results here.  Once we have that, we can easily generate a shaft test jig for you, with an array of D holes matching the shaft geometry, but varying from nominal size in steps of 0.05 mm.  It doesn't have to be very thick or large so should be quick to print, though to avoid inaccuracy due to 'elephant's foot' distortion of initial layers, it would be best printed on a raft.  Fit that to the shaft and tell us which over or undersize fits best, and those of us who have contributed models for you can  resize the D hole to best fit your shaft as printed on your printer.

Also, the shaft length measured from the panel, fully  pushed in (i.e. 'click' switch active) would be useful, though that dimension is less critical.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #24 on: January 20, 2024, 05:13:52 am »
I am measuring with calipers, but, to provide (more) accurate measurements, maybe I should wait for the rotary encoder samples to arrive (Ian.M, I believe you’re part of my other post regarding rotary encoders for my broken power supply) to find out if those will fit and replace the originals. From there, the datasheet will provide accurate measurements eliminating any error on my past.. edit: “part” (typing on my phone and auto correct messed up)

The knob that’s too large was suppose to be a 6mm D shaft (what I searched for and the description stated), and that fit (loosely), so my measurements SHOULD be accurate, but maybe mine are slightly off or my printer has poor resolution. (Anet A8).

Also, when I measured mine, it was 6mm give or take. When I looked online, they came in either 6mm or (I believe) 6.35mm. At that point it was too small to be 6.35 and too large to be anything smaller.
« Last Edit: Yesterday at 11:59:42 pm by bostonman »
 

Offline Psi

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Re: Resize a STL File For Me
« Reply #25 on: January 20, 2024, 07:37:01 am »
If you can convert this STL to a STP/STEP file, and have Altium you can do it by just making a new PCB, placing the STP file 3D body on the PCB at whatever size you want, then export the entire PCB as a new STL file.   Resize complete.

Not exactly a clean way to do it, but should work fine.


Failing that, FreeCAD will do what you want, but can be a bit hard to use if you've never used CAD before.
Maybe if you can find an online video showing how to resize a model in FreeCAD you can get something exported that fits your needs.
« Last Edit: January 20, 2024, 07:40:54 am by Psi »
Greek letter 'Psi' (not Pounds per Square Inch)
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #26 on: January 20, 2024, 03:49:03 pm »
I am measuring with calipers, but, to provide (more) accurate measurements, maybe I should wait for the rotary encoder samples to arrive (Ian.M, I believe you’re part of my other post regarding rotary encoders for my broken power supply) to find out if those will fit and replace the originals. From there, the datasheet will provide accurate measurements eliminating any error on my past.. edit: “part” (typing on my phone and auto correct messed up)

The knob that’s too large was suppose to be a 6mm D shaft (what I searched for and the description stated), and that fit (loosely), so my measurements SHOULD be accurate, but maybe mine are slightly off or my printer has poor resolution. (Anet A8).

Also, when I measured mine, it was 6mm give or take. When I looked online, they came in either 6mm or (I believe) 6.35mm. At that point it was too small to be 6.35 and too large to be anything smaller.

I found a site had a 6mm D-shaft dimensions:
Plus, it's an easy way to measure a shaft with calipers.



You might also what to check the calibration of your 3D printer.  I taped a pin onto my extruder and then laying a ruler on the print bed along each axis measured how far the extruder moves.  Then storing the printer steps/mm for that axis.  For example, set the extruder in one corner of the bed, align the ruler zero at the pin, tell the printer to move 200mm, measure the distance traveled, calculate and store a steps/mm adjustment value if the distances don't match.  Repeat for all three axis.
 

Online themadhippy

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Re: Resize a STL File For Me
« Reply #27 on: January 20, 2024, 05:40:34 pm »
slightly tweaked ,reduced the number of side slots ,made em deeper and made the D slot a smidge bigger.

Quote
I found a site had a 6mm D-shaft dimensions:
a rough  guesstimates  the flat length around 3 an a bit mm,which is different to the 6mm rotary encoder shaft i measure ,that had a flat length of 4.5mm
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #28 on: January 20, 2024, 08:11:53 pm »
Really close to the pictured knob.
Finally got my head in gear and figured out how to cut the side grooves and added the domed top.

1987132-0


My D-Slot dimensions (I can make them anything you want):

1987117-1


For completeness, here is the profile:
This is revolved 360deg around the z-axis.

1987123-2


Edit:  Adjusted D-Slot size
« Last Edit: January 21, 2024, 05:20:14 am by MarkF »
 
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Offline Infraviolet

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Re: Resize a STL File For Me
« Reply #29 on: January 20, 2024, 10:13:30 pm »
bostonman: a tip for you, look for the exe file installer for an old offline Sketchup version, version 7 or 8, from when Google owned it before the sale to Trimble. These will work under Wine on Linux.

Here's some mroe detail:
https://www.dedoimedo.com/computers/google-sketchup.html

If you install blender then you can import a downloaded stl in to blender, export from blender as a dae (collada), Sketchup 7 or 8 will import that dae, then you modify the mesh geometry in sketchup, and re-export to get it to blender, then export a new stl from blender.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #30 on: January 20, 2024, 11:07:42 pm »
It's much easier to just re-draw these simple parts instead of struggling to re-scale a
STL that doesn't match the part you're trying to replace. 

I'm using the newest version of FreeCAD 0.21.2, which only runs on a 64-bit operation system.

However, you can download FreeCAD 0.18.4 which will run on Windows XPCorrection:  Use FreeCAD 0.16  for WinXP.
There have been a lot of improvements and features that were fixed.
The learning curve is pretty steep but there are a bunch of videos to help get started.
« Last Edit: July 06, 2024, 02:28:32 pm by MarkF »
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #31 on: January 21, 2024, 09:01:19 am »
You might also what to check the calibration of your 3D printer.  I taped a pin onto my extruder and then laying a ruler on the print bed along each axis measured how far the extruder moves.  Then storing the printer steps/mm for that axis.  For example, set the extruder in one corner of the bed, align the ruler zero at the pin, tell the printer to move 200mm, measure the distance traveled, calculate and store a steps/mm adjustment value if the distances don't match.  Repeat for all three axis.

While you're doing the calibration, don't forget to do the extruder.  I load in a light color filament, measure off 110mm of filament from where it enters the extruder and mark the filament with a Sharpie.  Then, extrude 100mm of filament.  Measure the filament again that you have the 10mm left.  Store a correction into the printer if it didn't extrude the 100mm you told it to.

Repeat all your measurements until the printer moves the exact distances you tell it.  Obviously, the larger distance you can measure, the more accurate your calibration will be (i.e. Measuring 300mm would be better than measuring 10mm.  A 1mm error in measurement would have a lower impact if doing the 300mm distance.)
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #32 on: January 21, 2024, 02:17:57 pm »
Mark F, I downloaded Knob002-ver4 and opened the slicing software. I'll print this today, however, looking at it in the slicing software, it looks like additional shapes will be printed giving it the appearance it may not be smooth (see attached) - it looks blurry ironically. Maybe it's just how the slicing software is interpreting it, and the print will be fine.

It doesn't take long to print, so running these prints to test size and stuff isn't an issue anyway.

On another note, I was unaware my printer needs and/or could be calibrated. I'm uncertain who has experience with an Anet A8, it's a good printer, but my experience is that it's sloppy in many directions due to the nature of the printer. Many upgrades exist which I've printed and added, but I thought it was more about belt tension as most prints improved once I added braces and tightened the belts.

This is good feedback and I'll certainly look into checking the calibration.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #33 on: January 21, 2024, 05:48:13 pm »
I see what you mean about the look of the smoothness.  I expect it's just the mesh on the curved areas and the knob being so small.  I haven't printed it so I don't know how smooth it will be.  Try printing with a small layer height (maybe 0.12mm)


I can't find the original video I watched but here is one showing the process.
A few notes:
  • You will need to find the similar menus for your printer.
  • I don't like the extruder process which requires taking the printer apart.  That's why I say heat the hotend to 200oC, mark off 110mm of filament from where it enters the printer, extrude 100mm and measure filament to where you marked it.
  • Out of the box, I had to make some minor adjustments to get my prints dimensionally correct.  At least within a few thousandth.  We are talking small corrections here.  But when you're fitting parts together, these differences matter.

 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #34 on: January 21, 2024, 06:14:37 pm »
I printed it before your reply.

It seems to have printed fine. The side grooves aren’t too deep, but I suspect that’s my printer. Sadly, it still doesn’t fit on the shaft; which again may just be my printer. Even applying lots of force, enough to damage the new encoder switch, it won’t slide on.

I’ll have to look into the calibration when I get a chance this week before I print another.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #35 on: January 21, 2024, 06:35:15 pm »
Deeper grooves..
You said earlier that the Thingiverse knob fit loosely? 
I matched up the hole size to the Thingiverse knob.
(It's now 6.1mm with 4.7mm slot)

1987699-0
« Last Edit: January 21, 2024, 07:55:13 pm by MarkF »
 

Online Ian.M

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Re: Resize a STL File For Me
« Reply #36 on: January 21, 2024, 08:21:09 pm »
I wouldn't be surprised if the X and Y axes are off a mm or so in 100, so calibration will certainly be beneficial, but I would be very surprised if its off by a large enough percentage to affect the fit of a 6mm hole.  X and Y calibration on Prusa I3 clones like the Anet A8 is affected by belt tension, as they do stretch slightly under tension, so make sure the belts are tensioned correctly before calibration.

Extruder calibration is likely to improve small hole fit some, but the volume extruded is also critically dependent on filament diameter, and cheap filament may deviate significantly from nominal. e.g. 1.72mm instead of nom. 1.75mm is 3.4% less volume per unit length.    Take several measurements of the filament diameter for each new spool, and update your slicer's filament settings accordingly.   Even so, you will have to adjust small holes to compensate for the line being extruded dragging inwards as the nozzle moves round small radius interior perimeters, hence my suggestion to print an array of different fit holes test jig to see which hole fits best.  N.B. if you alter the perimeter extrusion speed or nozzle temperature, the required hole compensation will change some, so keep them consistent between test jig and actual part.

Also note that the as-shipped Anet A8 firmware is notorious for not having thermal runaway protection enabled, so unless you have upgraded to a version of Marlin compiled with thermal runaway protection enabled, *DO* *NOT* print unattended, even for only a few minutes.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #37 on: January 21, 2024, 08:26:52 pm »
I’ll try printing it tonight or tomorrow.

Yes, the Thingiverse was loose, but it’s fine as I planned to glue it. The original knob (as you probably saw) uses a V shape groove which I assume causes it to grip tighter on the shaft. Maybe the corners make a solid contact and the flatter part has less contact resistance allowing it to slide on easier and that’s how it manages to have such a strong hold without needing to force it.

Whatever the case may be, the fact a replacement knob now exists is absolutely amazing. Years ago we couldn’t do this, now someone at one part of the world can send a file to someone else and have a replacement part for the cost of a few cents in filament.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #38 on: January 21, 2024, 10:13:41 pm »
I overlayed mine with the Thingiverse knob and mine is ever so slightly smaller.
If your new print is too loose, I shave a little more off to make it tighter.
The last (ver6) is a 6.1mm diameter.  I could make it 6.05mm.  Let me know.

1987888-0

Mine = gray
Thingiverse = purple
 

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Re: Resize a STL File For Me
« Reply #39 on: January 21, 2024, 10:22:56 pm »
Another idea might be to adjust the size to slightly too loose then add a few narrow thin ribs on the interior flat of the D, along the shaft not cross-wise to add some crushability for a snug fit.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #40 on: January 21, 2024, 11:56:58 pm »
Quote
Also note that the as-shipped Anet A8 firmware is notorious for not having thermal runaway protection enabled, so unless you have upgraded to a version of Marlin compiled with thermal runaway protection enabled, *DO* *NOT* print unattended, even for only a few minutes.

Fully aware of this issue and appreciate the warning. The printer has been upgraded with the MOSFET for both the extruder (not necessarily needed) and the bed along with Marlin firmware. My goal was to add the Btouch (?) sensor, for auto leveling, but never got around to installing it.

Okay, here is the latest, something is odd. First off, keep in mind, I'm waiting on replacement rotary encoders that may or may not be the correct replacement due to size or whatever. With this being said, I'll gladly hold off trying to get a 3D printed knob that fits until these new encoders arrive.

With this being said, the most recent one still doesn't fit. I measured the encoder shaft, it's 5.98mm (I'm seeing 5.95mm at a few points - most likely worn down from removing the knob many times) and 4.48mm flat side to round part.

The Thingiverse part I printed (i.e. oversized knob) is approximately 6mm and fits tight enough that I can hold it upside down without it sliding off, but, if I hit the board on my hand, the knob falls off. The most recent one I printed from you is measuring approx. 5.44mm (and that's pulling on the calipers extremely tight).

Maybe something has shifted with my printer since I printed the Thingiverse one (because that fits and measures 6mm). Measuring the rest of the knob recently printed: base 18.25mm, top 17mm (hard to get a good measurement because it's rounded, height 13.05mm.

Give me a minute and I'll post a picture of the D hole being measured.

Edit: I also added a picture of the oversized Thingiverse hole size showing it's basically 6mm.
« Last Edit: January 22, 2024, 12:03:10 am by bostonman »
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #41 on: January 22, 2024, 12:41:05 am »
You got me now.
Somewhere you said our knobs were a little smaller than the original.
So, I increased the knob overall diameter.  The base diameter should be 18.4mm

With an overall printing error of 0.15mm, you D-slot diameter should be 6.1mm - 1.5mm = 5.95
But, you show 5.44mm

Here is a 6.25mm diameter slot.
The base is still 18.4mm.

What size would you like me to make it?
« Last Edit: January 22, 2024, 01:25:53 am by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #42 on: January 22, 2024, 02:04:56 am »
I haven't tried your latest version, however, I went into SketchUp (online) and created a 3mm radius circle (should be 6mm diameter - unless I or SketchUp mesed up).

In the slicing software, I put your Knob002-ver6.zip (which has a file name: Knob002 inside) next to the 6mm circle (see attached) - I also scaled it up to 200% for better resolution.

The outside oval is the skirt (ignore), the left is your knob, and the right is the 6mm circle. With my limited tools (or at the moment mentally drawing a blank on another method), I went into Photoshop, drew a thin rectangle around the 6mm (outside of the three yellow lines) to use for measuring, dragged it over, and compared the two.

It looks like the hole on the knob is 6mm because the rectangle fit in the hole (I thought maybe my slicing software wasn't interpreting the stl file correctly). Is it possible where I drew the red arrow that the radius is closing too soon causing the shaft to not fit in?

Ignore my statement and the red arrow as it appears the measurements you show in your 2D drawing match throwing my theory out the window.

I'm measuring the base and seeing around 18.25. The diameter changes as I spin it down to around 18.11mm, but believe this is due to catching the lines. Although the diameter changes, it doesn't seem that it printed oval implying one of the axis has a loose belt. In all cases, I'm not seeing close to 18.4.

I will still look into calibration and belt tension, but something is obviously off. Maybe printing it at 90% fill is causing issues or printing in the cold (it's in my basement) is causing issues.

 

Online Ian.M

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Re: Resize a STL File For Me
« Reply #43 on: January 22, 2024, 02:19:48 am »
Scaling off the original STL, as rendered by OpenSCAD, I got dimensions of 6.13mm dia, and 4.8mm  on the flat. but that's before printing, and as I explained above, unless the slicer software is advanced and very well tuned, FDM 3D printed small holes invariably close up some when printed.  It seems likely that a 6.13 mm hole was printing 0.13mm or so undersize and it felt loose because that wasn't enough to bring the D flat dimension down to the 4.5mm or so that would be needed for a slip fit to the existing shaft.

However you can get a false tight fit due to Z banding resulting in a hole that's snakey rather than straight sided, and as its got a flat, reaming to size is not a practical option.   

Try this test jig for fit on your existing measured shaft, preferably printed on a raft to avoid elephant's foot distortion.  It starts off at exact nominal size for the hole at the notched corner, and goes up in 0.1mm increments along its length.  The second row holes are 0.05mm bigger than the adjacent first row hole.  The max. oversize is +0.55mm, and if that's not enough, you probably need to fix/tune your printer!

Code: [Select]
shaft_d=5.98;
shaft_f=4.48;
h=3;
grid=10;
nx=2;
ny=6;
ovstep=0.05;
$fn=120;
$dd=1e-3;

module dshaft(l,d,f){ //l=length, d=dia, f=thickness at flat
    intersection(){
        cylinder(h=l,d=d);
        translate([0,f-d,l/2]) cube([d,d,l],center=true);
    }
}

//render()  // only needed (for preview) if graphics driver OpenGL is broken!
difference(){
    cube([grid*nx,grid*ny,h]);
    // --- cuts ---
    cylinder(h=h,r=1); // mark origin corner
    for(x=[0,nx-1])
        for(y=[0:ny-1]){
            oversize=ovstep*(y*nx+x);
            echo(str("[",x,", ",y,"] +",oversize," mm"));
            translate([grid*x+grid/2,grid*y+grid/2,-$dd])
                dshaft(h+2*$dd,shaft_d+oversize,shaft_f+oversize*shaft_f/shaft_d);
        }
}
« Last Edit: January 22, 2024, 02:23:13 am by Ian.M »
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #44 on: January 22, 2024, 02:59:04 am »
I don't see how the outside diameter is off by 0.15mm while the inside slot diameter is off by 0.5mm.  Over extrusion might cause some of that.  But not that much difference.

Until you do a calibration, you might try printing a 100mm x 100mm square that is only 2 or 3 layers.  Leaving a 50mm x 50mm hole in the middle.  See how close the measurements are.
« Last Edit: January 22, 2024, 03:07:08 am by MarkF »
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #45 on: January 22, 2024, 03:14:14 am »
Looking again at the knob print you did; are those ridges, highlighted in red, layer shifts?
They are going to have a hugh impact on the size.

1988107-0
« Last Edit: January 22, 2024, 03:15:47 am by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #46 on: January 22, 2024, 03:19:24 am »
I will print the test jig tomorrow; it's a great idea.

As loosely mentioned, I'm taking all the possibilities into account and will exercise calibration, belt tension, etc... For now, I just tinkered with the STL file for fun.

Sometimes I like to rule out the simpler things and/or just putts around with what is somewhat easier to rule out; in this case it was easy since I was sitting in front of the computer.

Ian.M, as usual, your input is very well accepted. It's quite obvious it's printer related, whether one or a combination of stuff you (and others) have mentioned.

Quote
Scaling off the original STL, as rendered by OpenSCAD, I got dimensions of 6.13mm dia, and 4.8mm

Just to clarify, are you referring to the initial one I posted that's too large (30mm ??) If so, then it would explain why it fit (and loosely) since these others were drawn at 6mm.

Does it make sense to make the hole as a V shape per the factory knob? As I mentioned, I'm guessing the V part allows for less of the surfaces to touch giving more room for error whereas a (half) hole has to fit a round shaft.

My printer isn't anything great as some of you may know. How I acquired it is a different story, but I printed many of the associated brackets allowing me to tighten the belts without bending the acrylic (or less bending). The shaft bearings were replaced for smoother movement, belts were tightened (may have stretched now), and I built an overhead filament holder reducing friction as the roll turns.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #47 on: January 22, 2024, 03:28:25 am »
Here are some closeups. It’s printed so the closed end is the bottom layer and I’ve noticed the printer doesn’t handle curves well, so the first layer is part of the support material and the curved part is a bit off. The sides are fairly smooth with the ability to feel the layers as I pass my fingernail across them.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #48 on: January 22, 2024, 03:28:46 am »
Another thing you can try is design a small cylinder with a 6mm hole in SketchUp.
You'll want to verify the inside and outside are smooth to rule out loose belts.
Adjust the size till you get a fit.  We can then adjust the knob in the short term.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #49 on: January 22, 2024, 03:30:48 am »
Here are some closeups. It’s printed so the closed end is the bottom layer and I’ve noticed the printer doesn’t handle curves well, so the first layer is part of the support material and the curved part is a bit off. The sides are fairly smooth with the ability to feel the layers as I pass my fingernail across them.

Are you printing it upside down?

You might try right-side up with supports.
Maybe the print is rocking on the dome as it prints.

With a 0.12mm layer height, the print should be extremely smooth.
Not what's in the pictures.
« Last Edit: January 22, 2024, 03:32:23 am by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #50 on: January 22, 2024, 03:34:35 am »
I'll try printing it the other way too.

Thought having less support material was better, so I flipped it.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #51 on: January 22, 2024, 04:08:38 am »
Overall, it sounds like you should really do the printer calibration and give it a good look-over for anything loose.
Especially since you've made a bunch of modifications and updated Marlin (correct?).
You should be able to do everything through the printer control panel.

I just changed a wore out brass extruder gear to a stainless steel one on my CR-10 today. 
That alone changed my eSteps for the stepper motor from 97 to 100.5.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #52 on: January 22, 2024, 04:25:57 am »
Quote
Overall, it sounds like you should really do the printer calibration and give it a good look-over for anything loose.
Especially since you've made a bunch of modifications and updated Marlin (correct?).
You should be able to do everything through the printer control panel.

Yes, Marlin and a bunch of modifications have been done. The belt tension upgrades could be implemented, but I never got around to it and always questioned their strength. I got the tension fairly tight and it seemed to make a tremendous improvement (but they may have stretched).

Eventually I found myself spending more time upgrading than actually using it; so I began accepting the prints as they were.

Most stuff I've printed wasn't dependent on such resolution, now I'm in uncharted territory. The printer has never been calibrated as I was unaware this was needed. The only calibration was trying my best to get the Z axis level along with bed leveling.

The test jig is a great idea and may provide just how far off my printer is, so let me provide some updates (hopefully) tomorrow.

 

Online Ian.M

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Re: Resize a STL File For Me
« Reply #53 on: January 22, 2024, 05:39:57 am »
Quote
Scaling off the original STL, as rendered by OpenSCAD, I got dimensions of 6.13mm dia, and 4.8mm

Just to clarify, are you referring to the initial one I posted that's too large (30mm ??) If so, then it would explain why it fit (and loosely) since these others were drawn at 6mm.
Yes, the STL from thingiverse attached to your initial post.
Does it make sense to make the hole as a V shape per the factory knob? As I mentioned, I'm guessing the V part allows for less of the surfaces to touch giving more room for error whereas a (half) hole has to fit a round shaft.
No. That is for a light press fit with injection moulded parts, and will have been carefully optimised for the original plastic used and the wall thickness of the shaft boss adjusted to allow the plastic to flex to make it work.   FDM 3D prints have anisotropic strength, usually far lower than injection moulded parts even with similar plastics, so the feature would need to be redesigned and re-optimised to work effectively without sheering off the shaft boss when it flexes.

Its much easier to simply tweak a D hole to fit reasonably well then figure out how to retain it.  Glue it as you proposed, or maybe a 2.5mm cross hole to allow a M3 grub screw to be tightened on the shaft flat.

My printer isn't anything great as some of you may know. How I acquired it is a different story, but I printed many of the associated brackets allowing me to tighten the belts without bending the acrylic (or less bending). The shaft bearings were replaced for smoother movement, belts were tightened (may have stretched now), and I built an overhead filament holder reducing friction as the roll turns.
Similarly, except my I3 clone has a plywood frame, which was a bit better braced than the Anet design.  I can generally get small parts to come out close enough to what I want.   If in an unheated room in winter, some sort of an enclosure is recommended to block drafts and control warping, which can be as simple as a very large cardboard box with a clear plastic curtain to cover the open front.  Use the Marlin menu to turn on the bed heater (only) to warm up  the enclosure well before staring the print.   If you trust its wiring and MOSFET, use its 90° (ABS) bed preheat setting for faster enclosure warmup.   I tend to do so at least 20 minutes before starting a job, then set the correct bed temperature when I open the slicer and give it 5 minutes or so to stabilise at the new temperature while I'm importing the STL and setting it up to slice and print.

On the subject of calibration jigs, Assuming you can run OpenSCAD, change the line:
Code: [Select]
                dshaft(h+2*$dd,shaft_d+oversize,shaft_f+oversize*shaft_f/shaft_d);to:
Code: [Select]
                cylinder(h=h+2*$dd, d=shaft_d+oversize);for round holes you can check against a gauge pin (or any other smooth round rod of accurately known diameter).  Set shaft_d (first line of script) to the actual diameter of the test pin or rod.

Edit: Another way of getting round holes is to simply set shaft_f (second line) to the same value as shaft_d.
« Last Edit: January 23, 2024, 05:35:39 am by Ian.M »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #54 on: January 23, 2024, 12:46:37 am »
I didn't see your message until tonight; and I already printed everything.

We've definitely established my printer needs some adjustments, but for the fun of it, I printed a few test items. First off, the test jig results are attached. The bright green were loosely fit (fall off the shaft loose if it was a knob), dark green fit tight but nice and snug (held onto the shaft equal to the factory knob), and red it wouldn't fit at all - notice third from the bottom on the left is a bright green.

I printed a square with a 6mm hole in the middle, using calipers, it measures approximately 5.62mm with some slight variations in all directions. Also printed was a 6mm cylinder (approx 7mm height) and measures 6mm and up to 6.18mm as I spin it (implying one belt is looser than the other - or it wobbled due to it's thin structure).

The latest revision knob was printed, without rotating it in the slicing software (made trying to remove the supporting material fun), one was printed at the default 0.3mm layer height (first layer is 0.35mm by default) and the other 0.12mm layer height.

The hole is measuring around 5.7 and 5.8 on both, but varies (it may be because how the calipers are seated in the hole and/or touching filament residue due to supporting material).

In any case, both knobs fit, it's very (and I emphasize that word) tight fit that requires lots of force, but it does fit. I wouldn't use this much force on the new encoders when I get them, so the holes could be sized slightly larger.

The current knob, with the exception of having to apply lots of force to slide onto the shaft, is perfect. The lines on the side, diameter, height, roundness, etc... are essentially equal to the factory one.

My suggestion is to wait until I get the new encoders to confirm they are the correct size/function and then just enlarge the shaft hole again.

If I mess with the printer belts and calibration, then we'll end up starting over trying to get a hole that will fit the shaft. My suggestion is to leave the printer as is for now, print the knobs with the compensating hole size, and then at some point I'll tinker with the printer.

« Last Edit: January 23, 2024, 12:48:13 am by bostonman »
 

Online Ian.M

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Re: Resize a STL File For Me
« Reply #55 on: January 23, 2024, 01:09:46 am »
The test jig may be indicating between 0.1 mm and 0.15 mm shrinkage on a 6 mm hole ID.  The red no fits near the notched corner are as expected but the cluster of five snug fits after the first loose fit  are not, so something odd is going on there.

The console log of the echo statements was:
Code: [Select]
ECHO: "[0, 0] +0 mm"
ECHO: "[0, 1] +0.1 mm"
ECHO: "[0, 2] +0.2 mm"
ECHO: "[0, 3] +0.3 mm"
ECHO: "[0, 4] +0.4 mm"
ECHO: "[0, 5] +0.5 mm"
ECHO: "[1, 0] +0.05 mm"
ECHO: "[1, 1] +0.15 mm"
ECHO: "[1, 2] +0.25 mm"
ECHO: "[1, 3] +0.35 mm"
ECHO: "[1, 4] +0.45 mm"
ECHO: "[1, 5] +0.55 mm"
which indicates it calculated the oversize for each hole correctly.  Hole id is [x, y] with [0,0] next to the notched corner.

Its suggestive of printer or environmental problems, possibly warping due to loss of bed adhesion at one end, resulting in 'dogleg' holes at the edge of the area that lifted.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #56 on: January 23, 2024, 01:47:38 am »
If you are satisfied with everything else about the knobs except the hole size, you may be better off just having the slicer scale the knob by 101% - 105% for a snug fit.
Whichever you choose, I'm perfectly happy to make any adjustments you want.


One point of interest:
   If your Anet stepper motors and lead screws are like Creality CR-10, each step results in a linear movement of 0.04mm.  For example, choosing a layer height of a multiple of 0.04mm will not require any partial steps.  I always choose layer heights of 0.08mm, 0.12mm, 0.16mm or 0.20mm.  I never go beyond 0.20mm.  That's just a personal choice.  My default is 0.2mm unless I want some fine detail.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #57 on: January 23, 2024, 03:44:16 am »
I've never changed any settings except infill and maybe some other basic settings.

Maybe the test jig got slightly warped when I removed it. The bed has painters tape for a base and I struggle to get some items from it. I've seen a rubber (?) sheet that is magnetic allowing it to be removed and making part removal easier, but never invested in it.

At some point I need to learn a bit more about 3D printing along with calibrating this printer since I've never done it. Unfortunately I don't do much printing, and, anything I've printed hasn't been affected by being off by a few millimeters.

This knob has certainly opened my eyes to issues with my printer. At the same time, I'm unaware just how accurate the printer should be making parts. My goal about two-years-ago was to install the belt tension adjustments. They don't strike me as very sturdy, but, either way, I thought having the ability to loosen them when the printer isn't being used would reduce belt stretching.

Another issue I felt was that it has so many upgrades available that I was basically putting three to four times into the printer whereas I could just buy a higher end one; so I began accepting prints as they were.

I never expected this knob design to be so involved. It's a power supply that someone hit, took out one of the two knobs (and encoder shaft) along with three banana jacks. It's not a high end power supply, but it was in the trash bin at work. Being able to bring things back to life for not only my benefit, but keeping them out of a landfill, is a nice felling.
 

Online Ian.M

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Re: Resize a STL File For Me
« Reply #58 on: January 23, 2024, 05:32:43 am »
My first useful print was a 'bumper' for an Arduino Mega.  It took quite a bit of fine tuning of my CTC DIY I3 to get one that fitted.  Back then I was also printing on painters tape, but switched to printing on glass with hairspray as an adhesion promoter, after I'd got fed up with replacing damaged tape every few prints.   Glass isn't for everyone, as to get a good first layer, the nozzle height must be more accurate over the whole part footprint, and any warping of the part typically results in total  adhesion failure and a failed print rather than just lifting a corner and continuing with some distortion the way printing on the more forgiving painters tape typically goes.  However, if you can cut the glass to size yourself, its a very cheap bed upgrade.   

I also had tensioner problems, as CTC had made some very strange design choices, and the D shaft used for the tensioner pully axles was trying to grind its way through the tensioner bodies, but I noticed the slackening belts in time and buying and installing the ball bearings they'd muntzed out  in the recesses still provided for them fixed that.  I generally leave the belts tensioned, as the plywood frame can take the strain, and simply switch on and move the axes every month so the belts don't take a set, but if I was storing it long term I would slacken them.
With an acrylic frame its less advisable to leave them tensioned as the plastic can warp or fail under sustained load, but as you need consistent tension for good calibration, its a PITA to have to frequently slacken them and retension to the same tightness.

Unless your bed is very flat and accurately levelled, having a BLtouch installed, with its probe as near the nozzle as practical, makes a big difference to larger footprint parts.  However as an Anet A8 typically has an ATMEGA1284P controller, getting Marlin built to fit with bed levelling enabled can be a PITA, as it only has half the memory of an ATmega2560.
« Last Edit: January 23, 2024, 05:37:11 am by Ian.M »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #59 on: January 23, 2024, 04:31:18 pm »
The glass and hairspray technique is something used previously. As a result, I have a piece of glass. The current setup is the metal original bed with the glass on top, and painters tape holding down the glass.

As mentioned, the item I saw about two-years-ago was a rubber (?) flexible sheet. if I remember correctly, a strip of magnetized metal gets taped to the bed, and this sheet sticks to it using magnets. After a print is complete, the entire rubber sheet lifts off and you can peel it away from the print, and then reapply the rubber sheet.

It looked quite useful, but at the time painters tape seemed to do the trick.

My Anet has a front and rear bracket mounted to it preventing (or reducing frame bending). If I remember correctly, the design shows to mount these utilizing the threaded rod, however, I have a piece of wood (clear stained) as a base and screwed the printed brackets into the wood. Also, the threaded rod has four brackets holding them down to the wood base as well. For some reason I remember using t-nuts, but, either way, the printer is mounted quite tight to the wood base (maybe 3/8" wood - not plywood - some sort of quality stuff I think). It even has the brackets for the upper part to reduce wobbling.

Basically my printer can be spun on every axis in the middle of a room and (hopefully) not see a shift in the frame - at least this is the image I have due to the amount of effort I put into making it sturdy. :)

The big issues are bed leveling (I absolutely agree that the BL Touch is a great improvement - I just never got around to adding it) and belt tension. Otherwise, I've taken into account all the mounting, reduced friction everywhere I could, etc...

I could be wrong, but believe due to the lack of features I care about (open thermistors shut down is the first feature I care about), I'm able to fit the BL Touch and standard features into the amount of memory available - you're correct though - it's awfully close to running out of room.

The personal issue I had was (as mentioned) felt I was dumping more time/money into the printer and using it to test upgrades rather than just buying some $2k unit that wouldn't need any (or much) upgrades.

My plan was to get a new PC, expand my interests on the mechanical side (I've taken on more interests doing 2D drawings and 3D designs), and maybe then upgrade to a new printer. My hurtles are that in order to transfer my extensive amount of software that I "obtained" years back when it was easier to "obtain", I'd need to "buy" updated versions. If I use a virtual XP system (or run two PCs) so I can still use my software, then I use old software that I can't use new files in. An example is say Altium. I can't take a new Altium file and have it open in a decade old version (or maybe I can, but just using an example).

Normally I use my work laptop for stuff and my XP to bang around. It's getting more ridiculous though to work around such issues as I just experienced with this knob where I have very limited options on taking a STL file and tweaking it or working with someone who has a CAD file who can share it so I can tweak it. My work laptop is limited on what I can do since I can't install anything and certain sites are blocked, but my XP is limited for obvious reasons. Also, I just dread new computers. Having to work through 30-day trial software, the quirks, installing codecs, etc... Wish XP would have just remained the OS forever. :)
 

Online themadhippy

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Re: Resize a STL File For Me
« Reply #60 on: January 23, 2024, 04:55:24 pm »
Have you tried to see if either your older machines,or possible the works machine can accesses the likes of tinkercad (https://www.tinkercad.com ) or onshape (https://www.onshape.com)

Quote
My hurtles are that in order to transfer my extensive amount of software that I "obtained" years back when it was easier to "obtain", I'd need to "buy" updated versions.
or leave the old machine alone and use it for those tasks,with the new machine dealing with modern stuff
« Last Edit: January 23, 2024, 05:01:45 pm by themadhippy »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #61 on: January 23, 2024, 05:38:24 pm »
I'll try later.

FreeCad (link was suggested in a previous post) didn't work with XP.

Years ago I had two computers aside of each other. One was used for old stuff and other stuff while the new one (current) was the one that would only run software I knew was safe. Eventually it got to the point where the old one took forever to boot and wasn't worth keeping.

Obviously options exist to keep my old system such as what I mentioned, a PC (forgot what those are called) that runs within a virtual window. From experience such as having two PCs is that it becomes not worth it anymore.

The answer really is to get a new PC. I should be posting questions about needing help with making a knob rather than having someone do it for me; or people helping by working around my PC limitations.
 

Online Ian.M

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Re: Resize a STL File For Me
« Reply #62 on: January 23, 2024, 09:30:41 pm »
I printed an encoder knob from my reply #19 OpenSCAD script, for a 5.95mm dia, 4.45mm thick D shaft today.  0.05mm oversize wasn't quite enough on my printer, 0.1mm would have been better choice, but a little work with a very small file to smooth out the slight layer ridges in the hole and it went on well enough.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #63 on: January 23, 2024, 10:10:18 pm »
Seems to me that you need one of these (Not for gaming):     :-+
   https://store.minisforum.com/collections/all-product/products/minisforum-n40-mini-pc


There are older versions of FreeCAD (version 16 lists WinXP):
Quite old.  Don't know how well it works.
   FreeCAD.0.16.6706.f86a4e4-WIN-x86-installer.exe

Plus there are Linux and Mac versions:
I believe the 0.18.4 is the last of the 32-bit builds.
   https://wiki.freecad.org/Download


Oh.  You might want to determine if the knob 6mm hole is the issue or the distance to the flat.
A round ~6mm hole would determine the hole size and the flat adjusted afterward.
« Last Edit: January 23, 2024, 10:12:51 pm by MarkF »
 
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Online MarkF

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Re: Resize a STL File For Me
« Reply #64 on: January 23, 2024, 11:48:34 pm »
Well, that was an adventure...

I installed FreeCAD 0.16 on my WinXP computer.

After install goto Edit->Preferences and:
  • Select Part Design as your default workbench.
  • Select navigation style to Touchpad.
    This will allow you to:
       Pan (hold Shift Key, no mouse buttons) moving the mouse
       Rotate (hold Alt Key, no mouse buttons) moving the mouse
       Zoom In/Out with mouse wheel
Creating the Knob is a totally different procedure than in the latest FreeCAD version.
Here is the knob using verions FreeCAD 0.16. 
The dimensions may be all wrong.  I did it from memory.


Here are the dimensions for the last non-FreeCAD_0.16 knob:

1989751-0

Edit:  Updated CAD file with latest dimensions.
« Last Edit: January 24, 2024, 03:26:28 am by MarkF »
 

Offline Infraviolet

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Re: Resize a STL File For Me
« Reply #65 on: January 24, 2024, 03:46:21 am »
I note you mention the knob is a bit loose, it's because 3D printed D shaft holes just aren't very good. The plastic is soft enough that in the really small volume of plastic wich experiences all the forces when torques are applied between the D shaft the the attached plastic thing, the force tends to distort the plastic. I'd always recommend trying to insert some nut slots and screw holes so you can use a screw to clamp against the flat side of the shaft.

This video:

shows how a screw and a nut can be used on a D shaft's flat, though if you go in from both sides 180 degrees apart with 2 screws you often do better as one screw has its end clamped against the flat and one has its end clamped against the curved side of the shaft opposite the flat. This should be a fairly simple geometry to integrate in to your knob. You can have the nuts slotted in from the bottom face, so the top one sees will still look smotth. The only visual difference will be two holes, of diameter sufficient for the screw's heads (M2.5 or M3 will do fine for low torque situations) coming in from the sides.
 

Online Ian.M

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Re: Resize a STL File For Me
« Reply #66 on: January 24, 2024, 06:36:00 pm »
If you are going to add a grubscrew, or if you need to add captive nuts in general to 3D printed parts, but don't want to mess with heat-staked inserts, do yourself a favour and use a square nut.   
e.g. https://www.mcmaster.com/97259A101/
Compared to a hex nut, the fit is far less critical, they are far less likely to spin in their hole. and have a greater surface area to transfer end-load to the part.
« Last Edit: January 24, 2024, 06:38:13 pm by Ian.M »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #67 on: January 25, 2024, 01:52:51 am »
I don't have much experience making 3D parts, but for me (and some of you from previous posts know I tend to go overboard), I think utilizing metal in certain applications is beneficial.

In the case of the shaft, make the 3D part so it can hold a metal insert (maybe brass) with a few spline lines (?) internal, drill a hole in the metal, thread it with a die, use two-part epoxy to keep the metal from slipping (the epoxy will go inside the spline lines for extra strength), and now you have a much stronger piece for a set screw.

My other thought is to make a part, if the software allows it, inverse the design so it's a mold, print it, and then use something like JB Weld to fill the mold. Now you have quite the heavy duty part.

Most likely printing with other material makes for much stronger stuff - but I only have experience with PLA.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #68 on: January 25, 2024, 03:57:11 am »
It's possible you may want to take the knob off or need to repair the power supply.
If the knob fails or starts coming slipping off, you can always print another or change its dimensions.
Maybe you want to change the color to match your outfit of the day...  :scared:
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #69 on: January 25, 2024, 04:08:03 am »
Quote
It's possible you may want to take the knob off or need to repair the power supply.
If the knob fails or starts coming slipping off, you can always print another or change its dimensions.
Maybe you want to change the color to match your outfit of the day...  :scared:

Were you referencing my previous message? If so, I was referring to the previous message about using a set screw for the design used in the posted video. In the case of my power supply, the existing design will be fine.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #70 on: January 25, 2024, 04:32:38 am »
Quote
Well, that was an adventure...

I installed FreeCAD 0.16 on my WinXP computer.


Did you get this error: DLL load failed %1 is not a valid Win32 application

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #71 on: January 25, 2024, 05:54:23 am »
Quote
Well, that was an adventure...

I installed FreeCAD 0.16 on my WinXP computer.


Did you get this error: DLL load failed %1 is not a valid Win32 application
No. I didn't get any errors installing version 0.16.
Are you sure you downloaded the 32-bit version?
I downloaded the x86-installer.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #72 on: January 25, 2024, 06:01:26 am »
It also ask to install the Visual Studio libraries. Accept and let it do them
 

Online Ian.M

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Re: Resize a STL File For Me
« Reply #73 on: January 25, 2024, 08:34:50 am »
Revised knob with grub screw hole and slot for a square nut.  Still based on resizing the original Knob_D_shape_rotary_encoder.stl from the first post.

Apart from some parameters for the nut, it only needs a few lines of code added in the cuts section of the difference().
Code: [Select]
    translate([0,knob_d/4,knob_h-shaft_l/2-recess_h/2])
        rotate([90,0,0])
        cylinder(h=knob_d/2, d=nut_size+slop, center=true); //grub screw
    translate([0, nut_thick/2+nut_to_shaft+shaft_f-shaft_d/2, 3*knob_h/2-shaft_l/2-recess_h/2-nut_af/2-slop/2])
        cube([nut_af+slop,nut_thick+slop,knob_h],center=true);  //nut slot
« Last Edit: January 25, 2024, 08:57:10 am by Ian.M »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #74 on: January 25, 2024, 03:56:30 pm »
Quote
No. I didn't get any errors installing version 0.16.
Are you sure you downloaded the 32-bit version?
I downloaded the x86-installer.

Sorry...Realized after I went to bed that I didn't specify the error occurred after installing, when I loaded FreeCad.

The link had several files, and I downloaded them all (maybe 12 or so). From what I could tell, two .exe files existed that both needed to be installed.

I'll have to do more investigating tonight. From what I could tell, it needs or depends on Python and/or VS stuff. I'm guessing something isn't linked correctly or I didn't install some library.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #75 on: January 25, 2024, 05:39:12 pm »
There is only one file to download and install (direct link to Github 32-bit Windows installer):
   FreeCAD.0.16.6706.f86a4e4-WIN-x86-installer.exe

The other files are for different operating systems, 64-bit Windows, or additional files required for compiling FreeCAD from the source code.  Sure, it uses Python, Qt and Visual Studio dll's under the hood.  But that's not your concern.  I see the 'over achiever' in you extends beyond just hardware.

As you say, there are two .exe files available.  One is for 32-bit Windows installs and the other is for 64-bit Windows installs.  You can't install both.  I see why you got the errors.  It's trying to use 64-bit libraries.  Un-install FreeCAD from the XP control panel and just install the 32-bit exe linked above.
« Last Edit: January 25, 2024, 05:45:30 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #76 on: January 25, 2024, 06:24:54 pm »
Quote
I see the 'over achiever' in you extends beyond just hardware.

That was funny. Sometimes I'm my own worst enemy.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #77 on: January 26, 2024, 02:48:33 am »
I'll need to dig into this more over the weekend, but still no luck.

Edit: I selected <view> <draft> and managed to get a window.

Not sure how this program works, but all, or most, in the "view" drop down menu gives the DLL error (that's the error I was referring to before).

« Last Edit: January 26, 2024, 02:52:29 am by bostonman »
 

Online themadhippy

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Re: Resize a STL File For Me
« Reply #78 on: January 26, 2024, 03:50:26 am »
Quote
Not sure how this program works
Best of luck,i spent sevral weeks trying to get to grips with it,watched countless tutorials,banged my head of the wall,watched more tutorials before deciding brain salad surgery would be simpler.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #79 on: January 26, 2024, 08:13:21 am »
I'll need to dig into this more over the weekend, but still no luck.

Edit: I selected <view> <draft> and managed to get a window.

Not sure how this program works, but all, or most, in the "view" drop down menu gives the DLL error (that's the error I was referring to before).

I assume this means you were able to install FreeCAD successfully and are having trouble knowing what to do next?   :-//

I linked to two Youtube channels a while back that have about 50 vidoes on how to use newer versions.  They probably won't get you over the first hump.  So here are some startup screen captures on setup and getting to a useful start place.
(Note.  The 'Draft' workbench is the last place you want to start.  Start on either the 'Part' or "Part Design' workbenches.)
  • This is the initial start page after install.
    Goto the Edit->Preferences tab to make viewing your model easier.
    1991524-0

  • On the 'General'->'General' tab set the Startup to 'Part Design'.  In most cases, the 'Part Design' is going to be the workbench you use most for complex models.
    1991530-1

  • On the 'Display'->'3D View' tab change the Navigation to 'Touchpad' (even if you don't have a touchpad!!!)
    Panning and rotating the model by pressing either the Shift key or Alt key and moving the mouse WITHOUT pressing any mouse buttons.  Zoom is with the mouse wheel and can be reversed with the 'Invert zoom' on this same tab.
    1991536-2

  • The next two are optional.
    On the 'General'->'Units' you can select millimeters or Imperial.  I do Imperial because my calibers has an analog dial that is in inches.
    1991542-3

    On the 'Display'->'Sketcher' turn off the 'Show grid'.
    1991548-4

  • After restarting FreeCAD you will see the 'Part Design' workbench'.  You can change workbenches from the dropdown box at the top.  On this 'Part Design' workbench you will draw a shape on a plane from which you can pad or cut using that shape to make a solid or cut a hole. 

    On the left will be two tabs 'Model' and 'Tasks'.  The 'Model' tab will contain a tree view of the shapes you have created.  The 'Tasks' tab you will use while drawing a sketch.  At this point, you first need to create a new empty document, create a sketch and then select which plane you want to draw on.  (Some of the videos will help with the actual drawing.)
    1991554-5

  • If you open the knob file for FreeCAD version 0.16,  it should look like this. 
    Clicking on an item in the tree 'Labels & Attribures' will allow you to turn that item on/off with the Spacebar, it will also allow you to change its properties in the bottom half,  double clicking will open the item to change it's shape and dimensions, you can also add new sketches to effect the model by clicking the 'Create Skectch' button on the upper left (box with red circle and square in it).
    1991560-6
« Last Edit: January 26, 2024, 08:33:55 am by MarkF »
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #80 on: January 26, 2024, 12:48:36 pm »
Not sure how this program works, but all, or most, in the "view" drop down menu gives the DLL error (that's the error I was referring to before).

Are referring to errors appearing in FreeCAD Report View window?

If so, you are going to get a lot of warnings and errors.  I pretty much ignore them unless FreeCAD refuses to do something.  FreeCAD is NOT a polished CAD program.  Even on version 0.19 that I started with, there were things that just didn't work.  FreeCAD is an open-source work in progress.  The newest version has come a long way since then.  Even still, there is a lot of capability available to you even in the old versions.

If you want a polished program, go purchase Fusion 360 or Solidworks.


All that being said, here is a video (using version 0.18 though) which will help you create sketches.



« Last Edit: January 26, 2024, 12:56:44 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #81 on: January 26, 2024, 02:20:41 pm »
I'll tinker with it more this weekend. Yesterday was a busy day, and I only had a few minutes to try uninstalling/installing before calling it a night.

In any case, the DLL error appears at the bottom when the program loads. Initially it was a larger window that I closed and it never seemed to reappear as the same size (even after uninstalling/installing).

The same DLL errors are a pop up window that appear whenever I select something from a drop down menu. Unfortunately the 'Start Center' is not what I see at all. My screen is empty with only file, edit, view, and help, drop down menus (and the DLL error on the bottom for a short time at startup).

The 'file' drop down menu only has 'exit' as an option. The 'edit' drop down menu only has 'preferences' as an option, The 'view' drop down menu has 'workbench' with sub options. Most of the sub menu options I've selected show the error: DLL load failed; %1 is not a valid Win32 application.

I believe selecting part and/or part design results in the pop up error window too, but I can't verify at the moment.

This PC has had many things installed over the years with some uninstalls. I have so many programs on it that I've had to combine stuff into groups as the 'start menu' went off the screen. My guess is I have a conflict, so I wouldn't devote too much time helping me since it's an XP system, and who knows what has happened to my PC over the years.

I appreciate the help, but I feel guilty since even I consider running XP silly. At some point over the weekend I'll tinker more, but I'll also try installing on a junk XP laptop I have.

Soon I need to look at what I have for software and make decisions on what I can live without (due to cost) so I can upgrade to a real computer without depending on my work one. Trying to upgrade to newer versions of software isn't..... hmmmm....... as easy let's just say to obtain as in the past. In the past I liked having a piece of software that was universal to stuff used in industry such as Solidworks, or maybe Altium, Xlinx, etc...

Obviously I can use free versions, hobby versions, limited versions, alternate software, alternate open source free software, etc... but knowing I'm designing something in a program that is a skill I can use in my profession is why I like name brand software; but it comes at a cost such as Altium being what.... $15k ?

For the record, about four-years-ago I began piecing together a system on pcpartpicker.com, and found myself overwhelmed with wondering how much I'll spend on software. I blinked, a year went by, blinked again, and now I struggle to view a 3D knob. :)
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #82 on: January 28, 2024, 04:40:31 pm »
Just an update.

I installed FreeCAD on my XP laptop, and it was night and day. It opened to the start up screen in your post and has many, many menu items now.

Not sure what is wrong with my PC as I've done an uninstall, a registry clean, etc... and FreeCAD gives me the same results.

In any case, I'm not looking for answers as this is XP we are talking about and obviously some software conflict, but wanted to post an update.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #83 on: January 28, 2024, 06:40:02 pm »
A silly thought..
I doubt it will make a difference but you could uninstall FreeCAD, then install the 64-bit FreeCAD, then uninstall 60-bit FreeCAD, then install 32-bit FreeCAD.  Then try opening FreeCAD again.

My thinking here is that since you installed both versions the 64-bit installer left something behind that the 32-bit installer isn't writing over.  Reaching for straws I know.  But, it might be a quick fix.


On another note.
I have some Bourns PEC11R encoders with 6mm metal D-shafts.
Their actual measures diameter seems overly large.  Hence, our knobs not fitting.
  - diameter = 5.97mm
  - flat distance = 4.47mm

I printed a knob that went on but was tight.  Maybe try a diameter = 6.35mm and a flat distance = 4.90mm
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #84 on: January 29, 2024, 02:04:31 am »
Quote
I doubt it will make a difference but you could uninstall FreeCAD, then install the 64-bit FreeCAD, then uninstall 60-bit FreeCAD, then install 32-bit FreeCAD.  Then try opening FreeCAD again.

You may be a genius, or it was a combination of what I did differently along with your advice. I installed the 64-bit version (still not sure why XP allows me to install it), uninstalled it, installed FreeCAD.0.16.6706.f86a4e4-WIN-x86-installer.exe, but this time I selected 'uninstall' (instead of 'repair') Microsoft Visual C++ Distribution Package when prompted.

Now it's finally showing the start center when I load it - much better and different than what was originally displayed.

Quote
I have some Bourns PEC11R encoders with 6mm metal D-shafts.
Their actual measures diameter seems overly large.  Hence, our knobs not fitting.

So you're saying my 3D printer is perfect and your design was off? (that was sarcasm).

For reasons not worth getting into, tonight I removed the Y-axis belt  (forward and backwards) bracket and discovered what once was a very little friction moving bed is now much harder to move.

From my experience, the two thin aluminum plates that mount the bearings and mount the bed are flimsy and bend easy. Most likely these bent over time from pulling off prints and causing stress on the bearings.

I'll print the knobs with my printer in the configuration it's in (i.e. needing calibration and adjustments) because I know what I'm getting at least. The knobs I've printed so far look great, so I'd rather not spend days over the course of weeks with the printer and not finishing the power supply repair.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #85 on: January 29, 2024, 03:03:44 am »
If you're talking about the calibration, that should take less than a hour.
You just take the measurements, do a calculation, change and store values via control panel and re-test.

You can just make the measurement and not make any changes to see how far off it is. 
Just measure the distance moved for each axis.

Edit:
  I should also point out that the save and store are two different things.
You can make the changes to try out.  But if you don't store them, the changes will be forgotten when the next time you power up the printer.
« Last Edit: January 29, 2024, 03:15:30 am by MarkF »
 

Online Ian.M

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Re: Resize a STL File For Me
« Reply #86 on: January 30, 2024, 11:04:18 am »
For reasons not worth getting into, tonight I removed the Y-axis belt  (forward and backwards) bracket and discovered what once was a very little friction moving bed is now much harder to move.

From my experience, the two thin aluminum plates that mount the bearings and mount the bed are flimsy and bend easy. Most likely these bent over time from pulling off prints and causing stress on the bearings.

I'll print the knobs with my printer in the configuration it's in (i.e. needing calibration and adjustments) because I know what I'm getting at least. The knobs I've printed so far look great, so I'd rather not spend days over the course of weeks with the printer and not finishing the power supply repair.
Probably a good choice to deal with the PSU first, as sorting the printer out is likely to be a big job.  However a stiff Y axis *WILL* cause problems with accuracy long before it gets bad enough to cause a layer shift so don't put it off too long.

Getting the bed bearings of a laser cut frame Prusa I3 style printer to run smoothly and normal to the Z axis is a PITA as four bearing beds with rigidly attached bearings are over-constrained.   The bed rails have to be level and exactly parallel to avoid the bed binding or twisting about the Y axis with Y movement.  However the front of the frame is only minimally constrained by the allthread that connects it to the main frame and back plate, and as the front plate generally has to be removed to remove the bed rails, you loose alignment whenever you need to take the whole bed off. 

Your fastening the frame down to a wooden surface may not be doing you any favours here as wood tends to expand and contract seasonally with changing humidity and warp if the surface finish or exposure to air circulation differs between the top and bottom surfaces + the coefficients of expansion of the acrylic frame parts, steel allthread and wooden surface will differ so unless you mounted it with a single fixed point at the center of the back plate, and all other points mounted with lateral compliance (e.g. oversize vertical holes and spring washers over flat washers), the bed rails will not stay levelled with respect to the Z axis and may not even stay parallel and in plane.

Assuming the bearings are still good,  their mounts need to be tightened in-situ with the bed on the levelled rails, otherwise it will invariably bind due to misalignment between the bearings.

There's also dirt and gumming to consider.  Linear ball bearings are highly sensitive to contamination of their raceways, far more so than rotating bearings,  so flushing with a compatible cleaning solvent and relubricating them with light machine oil would be advisable, and if they still don't individually run smooth replace them.  OTOH if you have low friction solid bearings, oil or grease + dust form a grinding paste that embeds in their surfaces and destroys them and the rails.  Cleaning + PTFE drylube may help, but if there is visible wear you'll probably have to replace them and maybe also the rails.

« Last Edit: January 30, 2024, 11:06:43 am by Ian.M »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #87 on: January 30, 2024, 04:04:11 pm »
Quote
Probably a good choice to deal with the PSU first, as sorting the printer out is likely to be a big job.  However a stiff Y axis *WILL* cause problems with accuracy long before it gets bad enough to cause a layer shift so don't put it off too long.

This is somewhat my thinking. I just have many projects at the moment, and part of the time I devote to moving unfinished projects out of the way to make room for another project that takes priority.

You're correct, the wood could be causing things to bow/expand/contract. Something I had considered, but weighted the options of a frame that twists when picked up or mounting and hoping for the best. I keep plastic over the top, however, dust could certainly have built up in the bearings too.

The bearings are all metal replacements, but, as you pointed out, the linear bearings are more sensitive. The major upgrades to my printer were (not including upgrading Marlin): replacing the bearings, four 3D printed brackets to hold down the threaded rod (two on each side, one in the front, one in the back), the 3D printed bracket to support the rear acrylic, 3D printed bracket to support the front acrylic, 3D printed frame to make the top acrylic (where the display is) more stable. Also, it's mounted to the straightest piece of wood I could find between HD and Lowe's - but this isn't saying much. :)

The BL Touch is the only other upgrade I felt was useful (bought it, but haven't installed it), anything more, and felt my money would be better spent on a high quality, less needy, printer.

If plans go correctly, this weekend I should knock off a few major projects which will allow me to free time for the printer. Seeing how stiff the Y-axis slid was quite disappointing to say the least as I devoted extensive time when I replaced the bearings to making sure friction was low.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #88 on: January 31, 2024, 04:27:18 pm »
Last night the rotary encoder samples arrived. Hopefully I'll have free time to install them, however, doubt I'll have the unit together since I still need to retro fit some binding posts onto the front panel.

Ideally, I probably won't get far enough to reassemble until sometime next week or the following weekend, but I'll post an update.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #89 on: February 07, 2024, 02:43:04 am »
Quote
I printed a knob that went on but was tight.  Maybe try a diameter = 6.35mm and a flat distance = 4.90mm

The encoders are installed, but this power supply is built with every consideration to save a penny. Disassemble once and you're lucky if the screw holes have enough thread life to catch the ridiculously short tiny screws. Two plastic standoffs broke when I disassembled it, the PCB the encoders mount to are (for some reason) causing one to sit at a slight angle (nothing I need to worry about). I think it's due to the new encoder having a slightly larger base.

A quick test showed the new encoders work. I'm still trying to solve the issue with the three broken banana posts before I fully reassemble.

I'm still familiarizing myself with FreeCAD. Currently I know enough to be dangerous, but one wrong click, and seems I can mess up the entire practice part.

Rather than risk messing up your design, can you resize and post it?
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #90 on: February 07, 2024, 11:56:24 am »
All you do is double click on the sketch, change the dimensions and export a STL file.
Don't save the file and just reopen it if you mess it up.
That old version will be a bit buggy.

Here's is a 6.4mm hole with a 4.9mm flat
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #91 on: February 07, 2024, 03:44:24 pm »
Thanks.

I'll try printing it in a few days.

A bit buggy or maybe it's just my inexperience using 3D software. At one point I did something to a practice design that suddenly made the solid portion (after I used Pad to make it three dimensional) that showed ghostly triangles on the face. After trying to export it to a STL, it would tell me I need to select what to export (I don't have the exact error message at the moment).

So yes, I'm still using training wheels at the moment. :)
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #92 on: February 07, 2024, 05:49:12 pm »
When it comes to exporting to a STL, you need to select what to export from the tree (i.e Model tab on the left).

You don't necessarily have to print everything.  You could export the knob without the hole.
In newer versions you can have more than one body.  For instance, a box with one body as the lid and a second body as the bottom.  By selecting one body at a time you can export two STL files (one a lid and one the bottom).


As I remember on the older versions you couldn't mix the 'Part Design' workbench with the others.  You could start with the 'Part Design' and go to another (i.e. 'Draft' workbench to add lettering) but you couldn't come back to the 'Part Design' to add more.  Most of this has changed now in the newer versions.  There are still some limitations that you need to work around even in the latest version.
« Last Edit: February 07, 2024, 05:55:13 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #93 on: February 07, 2024, 06:14:56 pm »
Quote
For instance, a box with one body as the lid and a second body as the bottom.

Ahhh this makes sense. So basically you don't need to design a box, and a separate design for a lid, it can be all one, but as separate STL files so it prints two separate pieces.

It didn't appear the manual went into detail about exporting to STL, and I haven't had a chance to watch more videos. I tried a CTRL-A to select everything in a tree, and THINK that had worked, but I was under the assumption the design had to be compiled or something rather than using such a method.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #94 on: February 07, 2024, 06:24:07 pm »
No.  There is no compiling.

In the box example, being able to see that two bodies fit together is a benefit.  Not sure if it's possible in version 0.16.  A work around is two CAD files where you can export the first as a STEP file (good for make parts for use in a PCB design program).  You can then import the STEP file into the second CAD file to compare.



Here each component was a STEP file inserted into the box bottom for layout and sizing.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #95 on: February 07, 2024, 07:13:38 pm »
Hopefully I do more mechanical 3D stuff. It is fun to see an idea come to life, be able to spin it in the software, and then print it.

Since I don't have experience with software like Solidworks (except the viewer) and whichever other ones are used in companies, I have a general question: are other pieces of software similar in how they function meaning they use constraints and similar methods?

Some of my 2D experience using AutoCAD is that line lengths and such can be manually entered rather than drawing a line and then needing to enter a constraint length.

I'm just curious how closely FreeCAD models high end software.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #96 on: February 07, 2024, 08:24:30 pm »
I can't help you there.  I don't have any experience with other 3D CAD software.
Like you, I used 2D AutoCAD back in the day.  And even that was doing circuit design.
I have a E.E. degree with 35 years of software development in modelling and simulation.
I retired 8 years ago due to health problems and now spend my time on my HO model railroad.
You can follow along here:  https://www.eevblog.com/forum/chat/model-trains/msg4729595/#msg4729595

All my FreeCAD designs have been mechanical items for my workbench, railroad or household repairs.



Oh.  In FreeCAD you can create a datasheet with your dimensions so you can resize things without going back through all your sketches to change sizes at multiple places.  You enter the variable name from the spreadsheet instead of a numerical value.  I did a lot of compontents for doing PCB designs.  See https://www.eevblog.com/forum/eda/tired-of-searching-for-basic-3d-cad-models/
« Last Edit: February 07, 2024, 08:31:20 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #97 on: February 08, 2024, 03:27:34 am »
Wow, you have some nice diversity.

Most of my 2D drawings are done in AutoCAD 2009, but I find it annoying. I took a CAD course as part of my curriculum, it may have been AutoCAD, but don't remember. In any case, I learned enough to do drawings, and, when I began using it again a few years ago, asked some co-workers at a previous job who used AutoCAD about a few areas I was (and remain) confused in. I know enough about AutoCAD to create basic drawings, however, I probably take the long way to create stuff which makes tweaking drawings a pain.

The last few years I've had a habit of creating 2D drawings in AutoCAD for many projects just for reference. This past summer I had an irrigation installed and used the 2D aerial view of my property I created a few years prior to map all the sprinkler head locations.

I went around my property measuring distances of the sprinkler heads, entered them into my drawing, color coordinated them by zone, did an approximate underground pipe routing drawing, etc...

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #98 on: February 08, 2024, 02:23:30 pm »
Ya, getting accurate measurements is sometimes the hardest part of the job.

The CAD training I had in school involved paper and pencil.   :-+
I still have all my drafting triangles, mechanical pencils, T-square, etc.  Collecting dust.

The version of AutoCAD I used run on DOS (prior to Windows).   :scared:

I bought a copy of TurboCAD years ago, but never got the hang of it.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #99 on: February 14, 2024, 02:35:44 am »
Earlier I printed the knobs at 0.12 layer height and began reassembling the power supply. The knobs look fantastic and add a bit of style since they give it (green) color.

The most recent STL you provided had them fit a bit loose. It was actually perfect because I didn't risk applying pressure to the new encoders trying to force them on (even the originals require a good amoutn of force to slide on).

Due to the cheap (and extremely tiny) plastic standoffs breaking off that hold down the PCB, I used some epoxy to hold down a few areas of the PCB, so I put a dab on the encoder shafts since I had some fresh mixed stuff.

In the future, if this power supply needs to be disassembled, the front panel will not go back together again. The screws are tiny and the standoffs break/strip, so the need to remove the knobs will probably never happen; unless I'm willing to clue all the PCBs back onto the plastic case.

Due to the many revisions of the CAD file you provided, I'm a bit confused on which one is the "final" version. I'd like to keep it so I can tweak it for other D shaft knobs I may need (actually just bought a used Lacroy scope today which is missing a knob, so I may need to print one for that too).

Which revision CAD file should I download and keep that can be easily edited?

Most likely I'll move onto tightening the belts and calibrating my 3D printer since I don't have an immediate need for it. Yesterday I printed a 30x30x10 square I made in FreeCAD to check the calibration. Ironically it was almost perfect in two of the three sizes (I forgot which one was the X and Y, so I don't know which one is off, however, I'll be calibrating all axis).

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #100 on: February 14, 2024, 06:02:31 pm »
Here are the Knob2 files for both the old 0.16 and the current 0.21.2 versions of FreeCAD.
These files have the dimensions for the D-shaft of 6.4mm diameter hole and 4.9mm flat
used in the last STL file I posted.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #101 on: February 14, 2024, 07:00:09 pm »
Great, thanks again!

Hopefully your design will help others too. If all it needs is a few tweaks to resize the overall knob, then this could be quite useful to others since test equipment is prone to broken knobs.

This has certainly opened my eyes to being reminded of becoming more knowledgeable with 3D designs. What a great time we live in that helpful people can create something in one part of the country/world, send the file, and the end user can just print the part to fix their issue.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #102 on: March 28, 2024, 02:55:46 am »
MarkF,

I have a few questions but not sure if I'm going to ask them correctly. Since you created the 6mm shaft knob, referencing it may be the best way to ask my questions.

Basically I'm trying to expand my 3D modeling knowledge and using FreeCAD to do so. Much like other 3D models I've seen, you have several separate sections such as: Revolution, Sketch, Pad001, Sketch001, Sketch002, etc...

As I click on different sections of the knob, specific sections get highlighted. I'm curious why or when is it appropriate to create a separate sub part/section.

To be more specific, before I thought if I were to create a 3D model of a car, I'd create the body, engine, tires, etc... as individual pieces. What you seemed to do is create many separate pieces within just one part.

Recently I downloaded the STEP file for a BNC connector for reasons not worth getting into. The STEP file had numerous individual pieces all within just the BNC. So again, I'm wondering how/when this is done.

With your knob, as I click on each section, it gives me the impression numerous separate pieces were used, but I can't follow it.

Also, although I have several lingering questions I'm trying to work through with FreeCAD, one basic general question is say I wanted to add something like a plate for the knob to sit on. Let's say I wanted to make it a trophy. How do I make the plate "touching" the knob so it's all one piece that gets printed? I think this is called a face, but I haven't found any tutorials that explain this.
« Last Edit: March 28, 2024, 02:57:38 am by bostonman »
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #103 on: March 28, 2024, 01:47:46 pm »
I guess my first question is which version of FreeCAD are you referring to?

In the old version (discussed earlier), it is not possible to create multiple parts.

As far as order is concerned, in many times you don't have a lot of choice.
Certain operations depend of previous ones.  For example, you can't cut a hole in a part
you haven't created.  If you wanted to add a plate to the knob as you suggest, you would
just create a new sketch to the last operation in order to create a pad or perform a
revolution operation.  In the newer versions of FreeCAD, you can create multiple bodies
to build up your model.

The order you create the model depends a lot on what you're modelling.  Most likely, you
will build the model from the inside out.  Mainly you create a sketch, use that sketch
to perform a further operation (pad, revolve, cut), and then a boolean operation in some cases.
After you're comfortable, you can move to the 'draft' workbench to add text.  More advanced
operations to learn are the loft and pipes to create a curved surface or to draw a sketch along
a path.  In the beginning, you try to do things a certain way and find out you can't get from
point A to point B and will need to do it differently.  Especially in the older versions.
I do most of my modelling in the 'part design' workbench building sketch upon sketch.
Think of a sketch as the shape of the tool you will use to draw with.

I can suggest a few YouTube channels:
  - https://www.youtube.com/playlist?list=PL7eiW2bt21YU6QEbly78kUgQCNEiDUwSH
  - https://www.youtube.com/playlist?list=PLWuyJLVUNtc0UszswD0oD5q4VeWTrK7JC

Perhaps a photo of the two versions of FreeCAD:
  2087690-0
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #104 on: April 07, 2024, 01:58:30 pm »
I watched some of those videos and will watch more as time goes on.

Recently I wanted to make a shape (using Free CAD v0.16) and attached a general sketch. In order to make this, I made the outside circle 50mm, the next one in 40mm, and then used pad to give it height.

After I added another shape making the circle 40mm (so it meets the previous circle), the inside one 15mm, and used pad to bring the height slightly less than the other shape.

Although the object came out correctly, I sense this isn't the correct way to do it; nor does the slicing software seem happy because it's doing some funky stuff with the layers. If I try adding a chamfer to the outside (higher raised) circle, the slicing software seems to not see it (even though I exported all the associated stuff in the left side panel).

I'm not asking for someone to create this, but only asking whether this needs to be done as two sketches, add something, or whatever, so I can learn. Keep in mind, I'm still trying to wrap my head around creating parts beyond a simple 2D sketch.

Also, I've yet to find why FreeCAD has a robot workbench. Does anyone know the reason for this? Although it's cool, I don't know what purpose it serves.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #105 on: April 07, 2024, 02:19:32 pm »
I think the problem is that the inner disk and the outer ring are being seen as two different parts.
(i.e. the 40mm intersection is exact between the two.)
FreeCAD has some problems with exact edges like that.
You can try changing the inner disk to have its diameter equal to the diameter of the ring (i.e. 50mm or 40.001mm).

A better way of creating the part may be to create a disk with 50mm diameter with 20mm height and 15mm hole.
Then cut out the 40mm x 10mm hole from the inside.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #106 on: April 07, 2024, 02:53:32 pm »
Quote
I think the problem is that the inner disk and the outer ring are being seen as two different parts.

From how I interpreted the image/stl, this was my thought too.

Quote
A better way of creating the part may be to create a disk with 50mm diameter with 20mm height and 15mm hole.
Then cut out the 40mm x 10mm hole from the inside.

I'll try this method tonight.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #107 on: April 07, 2024, 03:30:40 pm »
I just recreated the part as you described including the chamfer without any issues in version 21.2
This might just be something that works better in the newer version of FreeCAD.

Like I said a while back:  "Sometimes you just have to tinker with how you create a part to make it work."


Also, I was able to create a STL and slice your zip file part without issue.
This also might be how the new version of FreeCAD creates STL files.


FYI: I'm using the latest PrusaSlicer on Windows 7.
I left Cura in the dust since they don't want to support Windows 7 any longer. 
Also, I hated the way you have to control Cura's view angle on a laptop without a mouse.
I wish both slicers would adopt FreeCAD's SHIFT/ALT pan and rotate control.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #108 on: April 07, 2024, 03:56:30 pm »
I have a Win7 laptop as well that I can install V21.2 on.

Quote
Like I said a while back:  "Sometimes you just have to tinker with how you create a part to make it work."

I fully agree and it's why I tried making the second circle equal to the diameter of the other circle. In my mind, it didn't make sense because, as you stated, and I assumed, it's making two separate parts that "touch" each other rather than uniform.

My point is that I did spend time tinkering. In my slicing software, one view didn't show the chamfer, but the 3D view did, however, it also showed support material embedded in the inner circle; this is when it being wrong was obvious.

I attempted to print the part for fun, but it came out looking worse than expected.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #109 on: April 18, 2024, 03:51:25 am »
I'm uncertain whether I should start a new thread.

Periodically I tinker with FreeCAD (0.16) and trying to learn all the options. One option is the 'groove' option and I watched a video ().

Following the video to a degree, I managed to create a groove, but I don't understand what I actually did.

At approx. 2:40min into the video he creates a rectangle on top of the cylinder. First he created a cylinder, created a rectangle on top (for some reason), created the groove pattern, and then used that to make a 360 degree groove around the cylinder.

How is this different than using rotation?

Why was the rectangle needed?

Due to errors in my attempts, does the groove pattern need to be spaced a specific distance from the vertical axis?

It got somewhat confusing why another sketch was created, then pad was selected, another sketch, etc...  I managed to create a funky looking groove in my cylinder, but don't quite get the reasons for the steps including the last three or four steps after the groove was completed (and the rectangle was removed).
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #110 on: April 18, 2024, 12:37:58 pm »
How is this different than using rotation?
- The 'groove' tool basically does a rotation and then a cut.  It's doing multiple operations with one tool.

Why was the rectangle needed?
- The little rectangle on the top was to provide a reference face along the X-Z axis for the groove tool to operate upon.

Does the groove pattern need to be spaced a specific distance from the vertical axis?
- In this example, the 'groove' pattern will be revolved around the Z-axis.  So, you can't have any part of the pattern on the negative X-axis.  If you place part of the pattern on the Z-axis, the 'groove' tool will cut the object in half.

It got somewhat confusing why another sketch was created, then pad was selected, another sketch, etc...
- As mentioned above, the 2nd sketch and pad was to provide a reference plane for the 'groove' tool.  In the newer versions of FreeCAD, I didn't need to create that 2nd sketch.  I was able to reference the X-Z plane directly.  You have a more ways of creating reference planes in the newer versions.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #111 on: April 19, 2024, 02:53:52 am »
Sorry, I used the term 'rotation' and meant 'revolution' (located in the design drop down menu). At one point I tinkered with revolution, and, when I accomplished a groove pattern, wondered if a difference exists.

Quote
I was able to reference the X-Z plane directly.  You have a more ways of creating reference planes in the newer versions.

I assumed the groove "reference" was the vertical part of the groove pattern, however, if this is an outdated method and revised in later versions, no sense pondering on the topic.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #112 on: April 19, 2024, 12:39:22 pm »
I don't know if there is a question there...

FreeCAD 0.16 was released in April 2016.
While it is terribly out of date, you still need to understand how
that version of the program works in order to be productive.
It wouldn't be important to others, but it's worth your time.

Let me pose a modification to the exercise in the video.
How would you rotate the groove pattern around the X-axis instead of the Z-axis?
I haven't tried this.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #113 on: April 19, 2024, 01:39:53 pm »
Quote
How would you rotate the groove pattern around the X-axis instead of the Z-axis?
I haven't tried this.

That's a good question and I'm uncertain.

While I grasp some of the concepts, I don't necessarily understand the steps. At the end of the video he adds a sketch to the face of the rectangle, does something else, and makes it "vanish". Not sure why the rectangle sketch just can't be deleted at that point, however, my point is that it's a step I can easily follow but don't understand.

Per your question, a twist is: after making a cylinder, if I want to attach a square perpendicular to the cylinder, how do I attach the face? Each time I tried this last night, the square (or rectangle) would attach itself to the center of the x-axis.
 

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Re: Resize a STL File For Me
« Reply #114 on: April 19, 2024, 04:13:51 pm »
Not sure that I've figured out how version 0.16 is working.

However if you draw a cylinder around the z-axis as in the video.

Select the top cylinder end face as the reference to create the reference sketch (as the video).
Draw a square with two edges on each of the x-axis and y-axis in the positive direction.
Pad the reference square to a cube.
(Basically, make the little rectangle and pad in the video into a cube for more clarity.)

Now you have a cube which you can use to reference any of the faces in order
to create your cutting pattern.  The revolve then allows you to rotate the cutting pattern
in either the horizontal or vertical directions.

Clear as mud???   For me too.


To answer an earlier question, you can't delete this reference cube because that would
break the draw path used to update the part.  You can only add a cut of the cube at the
trailing end of the operations.
« Last Edit: April 19, 2024, 04:22:12 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #115 on: April 19, 2024, 04:56:01 pm »
I’ll tinker with it over the weekend.

Just for the record, I’m not necessarily trying to perfect learning FreeCAD, but more about trying to understand the foundation of it so I can understand what I’m actually looking at when I create a model. The goal and obvious method is to use the latest version rather than learn outdated tools, but I like learning the foundation rather than just steps.
 

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Re: Resize a STL File For Me
« Reply #116 on: June 27, 2024, 01:33:37 am »
I hate to request another knob, but I tried tinkering with the design in v21 and can't figure out much.

Recently I purchased an Agilent 54831M scope with a missing horizontal knob (and broken shaft - something I'm in the process of replacing). I already have the same scope, so I'm able to measure the knob (and provide pictures which I'll post shortly).

I tried tinkering with the current knob design, but I couldn't figure out the tree structure. Is it too much trouble to edit the design (or create a fresh one if that's easier)?

You'll notice the face is slightly curved, but, I'm not looking for a perfect match, just something somewhat close. Due to the encoder being replaced, the current shaft size is a D shape and I've attached the dimensions from the datasheet.

On a side note, the knobs are slightly rubber type (I guess for better gripping). Does a filament exist that would be hard like PLA but slightly rubbery?

Edit: it would probably help if I included dimensions :)

base: 0.965" diameter
face: 0.9" diameter
length: 0.5"
little dimple on front: 0.38"
« Last Edit: June 27, 2024, 01:38:19 am by bostonman »
 

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Re: Resize a STL File For Me
« Reply #117 on: June 27, 2024, 04:12:13 am »
Do you still want it in the old version of FreeCAD?

How many flutes (i.e. indents) are there on the outside?

How far does the shaft stick out from the scope face?
  (i.e. is the depth of the D-slot even with the scope face?)
« Last Edit: June 27, 2024, 07:02:30 am by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #118 on: June 27, 2024, 01:05:14 pm »
I'll count the flutes later.

The encoder shaft (as mentioned) is broken and replacements are unavailable. Someone on eBay is selling used ones for $92 (or so), but long story short, I found an alternate. The encoder leads need to be connected differently, and the only other difference is the shaft length.

From what I can tell, it's maybe 2mm shorter, but panel doesn't allow for the knob to go in any farther. The original knob D slot is flush with the back of the knob, so a 2mm shorter shaft shouldn't be a problem. If anything, I can (and probably will) put a dab of epoxy to hold it on.

It can be done in v21. My laptop runs that and I know it's easier.
 

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Re: Resize a STL File For Me
« Reply #119 on: June 27, 2024, 01:23:38 pm »
I have struggled with this one in version 0.16.
About ready to give up on the finger flutes on the outside when I thought of a new approach.
You should be able to open it in either version of FreeCAD.

Here is a version with 11 flutes you can have a play around with:
 - You can change the flute count by selecting the 'array' in the tree and changing 'number polar' in properities.
 - I just took a wild guess at the D-slot.  So, fix the dimensions in 'sketch002'.
 

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Re: Resize a STL File For Me
« Reply #120 on: June 27, 2024, 01:54:21 pm »
Thanks. I'll look at it later.
 

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Re: Resize a STL File For Me
« Reply #121 on: June 29, 2024, 09:15:24 am »
I thought I would take this opportunity to create a teaching moment for anyone who would like to see how the knob was created.  This was done with version 0.16 of FreeCAD.  If using the newest version, you would probably do this with two bodies (one with the knob shape and another with the cutting objects).  Also as you do each step, FreeCAD seems to re-arrange the objects in the tree view.  I did screen captures of the final model.  So your tree will look different until completed.

Step 1:
  Create the knob profile and revolve it around the z-axis.  (via 'Part Design' workbench)

2297727-0

Step 2:
  Create and pocket the D-shaft hole.  (via 'Part Design' workbench)

2297731-1

Step 3:
  Create the cutting shape.  (via 'Part Design' workbench)
  Sketch, then Pad, then Fillet.

2297735-2

Step 4:
  Make an array of all the cutting surfaces. (via 'Draft' workbench)

2297739-3

Step 5:
  Cut the finger flutes into the knob.  (via 'Part' workbench)
  Select knob pocket, then cutting array, then cut.  (Windows CTRL+click for selecting multiple items in the tree.)

2297743-4

Step 6:
  Fillet the upper edge of the knob.  (via 'Part Design' workbench)
  Try to do fillets and chamfers as late as possible in the process.  Of all things they tend to break FreeCAD most of all.  You can not fillet or chamfer a distance greater or equal to the width of the surface.  Also if you modify an earlier sketch you will inadvertently change what edges are filleted or chamfered and will need to redo them to select the proper edges.

2297747-5

« Last Edit: July 02, 2024, 09:54:56 am by MarkF »
 

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Re: Resize a STL File For Me
« Reply #122 on: July 02, 2024, 03:28:27 pm »
I plan to look into tweaking this based off your feedback and tutorial.

As you mentioned, the tree structure seems to change in FreeCAD. Even though I've tinkered with FreeCAD several times, the tree structure is still challenging.

At the moment I'm dealing with a scope problem after reassembling, so tweaking and dealing with the knob is somewhat on the backburner.
 

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Re: Resize a STL File For Me
« Reply #123 on: July 02, 2024, 06:28:17 pm »
I noticed your other thread on replacing the encoder.  It looks like you're getting enough help, so I haven't been following it.

FreeCAD's tree is the mechanism for display/selection/edit of items. 
It is the basic flow of the creation of the model. 
You have little to no control over the order of those items.

How I navigate/use the tree as a novice (in no particular order):
  • Show/hide the visibility of an item (click then space-bar).

  • Transform a body (rotate and/or move)(right click).

  • Change an item's appearance (color and transparency)(right click).

  • Toggle 'active' body you wish to modify (if more than one)(right click).

  • Double-click to edit an item.

  • Create a 'link' (i.e. make a clone copy) of a body.
    For example, I created an HO scale office building.  The front, back, roof and one side wall were each a body.  I cloned the wall for the other side because both side walls were identical.  That allowed visualization of all sides while creating the interior.  Each body was then exported individually as STL files for 3D printing.

  • Selection of items for export.
      Export to a STL file for 3D printing. 
      Export a STEP file for use as a model in PCB software or to import back into FreeCAD.

  • You have a very limited ability to move a sketch from one body to another.

Create a separate body for each part of what you're making.  This allows you to place each in their proper location to insure that they match their counterpart.  For instance, a mount of some kind with multiple joints.  Each leg would be its own body with a joint at each end.  Then, you lineup the bodies at their joints.  You can animate the joints so the bodies can actually move but that's beyond my skill level.

I believe the 'body' was introduced in version 0.19.  But don't hold me to that.

The spreadsheet is very helpful too.  Instead of hardcoding dimensions, you place them in a spreadsheet allowing you to resize your model without the need to go into every place you used a particular dimension. 
I did a capacitor model and used a spreadsheet to define multiple capacitors for export.  See https://www.eevblog.com/forum/eda/tired-of-searching-for-basic-3d-cad-models/
« Last Edit: July 02, 2024, 06:41:28 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #124 on: July 02, 2024, 07:14:28 pm »
I'll tinker with this at some point. My goal was to reassemble the scope and tinker with the knob, but, after reassembling, the scope isn't working correctly. If things went according to plan, the scope would have been somewhat finalized and I'd be tinkering with the knob for ascetics.

BTW, the knob you made has a great height and width and both ends. I failed to mention this.

 

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Re: Resize a STL File For Me
« Reply #125 on: July 05, 2024, 04:22:19 pm »
I forgot to tell you that you will get a better finish
on the top of the knob if you use a smaller layer height.

For me, working layer heights are 0.08mm to 0.28mm in 0.04mm steps.
The 0.04mm height is so the stepper motor doesn't have to do partial steps.
With even steps, all the layers will have the exact same height.

I saw a video a long time ago on how to calculate what the even step height is
give a particular stepper motor and lead screw pitch.  Can't find it anymore.
« Last Edit: July 05, 2024, 04:28:18 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #126 on: July 05, 2024, 04:35:39 pm »
I assumed playing with layer heights would need to be done. The initial print was to get an idea of what I was working with.

The layer height was decreased, but forgot what I tried. Either way, it’s a great knob and don’t mind tweaking things a few times to get it correct.

The only suggestion I thought of was mankind it more hollow to save filament, however, I may try printing in TPU (whatever the gasket type filament is that I have) to get the rubber affect the original has so too hollow and it may be too soft. At the moment I just have clear, so maybe I’ll invest in grey if it proves to be a good alternative.
 

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Re: Resize a STL File For Me
« Reply #127 on: July 05, 2024, 05:42:19 pm »
Found it!  Had it bookmarked all along.
Here is that video on layer height and exact motor steps:

 


Also, here is a video showing how I calibrated my three axis and the extruder:

 
« Last Edit: July 05, 2024, 05:49:55 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #128 on: August 13, 2024, 02:08:01 am »
MarkF,

You've been following the TPU jamming issue thread and wanted to update this thread.

I printed the knob (forgot the settings I used for the G Code) after fixing the TPU jamming issue and the knob looks great.

The diameter is perfect on both the face and base, and the height is perfect.

You've provided information on how to tweak the design, so I'll go back and read them because the design needs some changes, and I'll tinker with it when I get some time.

All that I need to do is:

It has 11 flutes and the original is 12 (you provided directions on how to add/subtract flutes).

The flutes could be deeper as they are not as pronounced (could just be the limitations of my printer and the resolution)

The face lacks the dip (I tried a better resolution setting and the dip doesn't seem to be visible). I'm uncertain if the dip isn't being exported correctly into the STEP file or the printer just is lacking the resolution.

The hole for the shaft needs to be larger

From what I see, printing with TPU (I forgot which infill setting I use) is perfect. The knob is solid with a nice slight rubber feel. I expected it to be soft, but it's perfect.

If I perfect the knob size, I'll probably plan to purchase grey TPU filament so it matches the rest of the knobs.
« Last Edit: August 13, 2024, 02:22:14 am by bostonman »
 

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Re: Resize a STL File For Me
« Reply #129 on: August 13, 2024, 09:23:30 am »
Good job.

As for the dip, I seem to remember the top just has a flat spot.
You should be able to change the knob profile to add a dip.
It would be changed in the sketch being revolved to get overall shape.

The flute deep is a real compromise as it tends to break the model.

I'll take another look if you can't get it fixed.
 

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Re: Resize a STL File For Me
« Reply #130 on: August 13, 2024, 12:07:21 pm »
I couldn't resist having a play with the knob while watching the news this morning.

I fixed the number of detents to 12 and over exaggerated their depth and width.
The problem with them is probably due to TPU being so soft. 
They wouldn't look good if printed in PLA.

I also added an arc depression on the top of the knob instead of being flat.

I didn't adjust the D-slot hole.  You know best how much to change it.
« Last Edit: August 13, 2024, 12:09:24 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #131 on: August 14, 2024, 03:45:03 pm »
Thanks, I'll download this soon and try printing it.

The original knob doesn't have very deep flutes (or detents?), but, I think due to the better resolution design, they are more defined in appearance. The knob doesn't have to be identical, just needs to look decent and fit, so I'm not trying to make it perfect.

Keeping in mind I didn't tinker with any fine tuning when I printed this latest knob (I used the previous GCODE but don't remember the settings - I think 0.12 resolution), the face was rough.

I attempted to sand it, but sensed it wouldn't sand well since it's more like rubber, and seems I was correct.

Any methods I can use to smoothen the face when I get a print I'm satisfied with?
 

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Re: Resize a STL File For Me
« Reply #132 on: August 14, 2024, 08:43:50 pm »
You will still have to tinker with the shaft hole.  Version 5 of the knob is the same size as version 4.

As for smoothness, you can go to fine layer height (the smallest I ever print is 0.08mm) or you can try the 'variable layer height' option.

What slicer are you using.  I wrote a program to parse a gcode file and extract the most relevant setting used.  It is mainly for the PrusaSlicer since they append almost every possible setting to the end of the gcode.  It also parses gcode from Cura.  But, it is hit or miss because they only append a few settings (totally unpredictable what they include).

Screenshot:
  2339305-0


** UPDATED 'G-CODE VIEWER' TO INCLUDE ADDITIONAL OPTIONS PARSED FROM 'SLIC3R' G-CODE **
« Last Edit: August 23, 2024, 12:19:06 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #133 on: August 15, 2024, 02:38:39 am »
I use Slicr3r (see attached screen shot).

It's one I downloaded upon first getting my 3D printer and grown (somewhat) acquainted with it.

Maybe my Anet A8 is more capable of printing a smooth face, but I haven't had much luck with the finer details of a print, so my opinion has been: that's the best my printer can do.

Certainly I plan to tweak the settings, and maybe that's all it needs, but the last knob (printed in PLA) had all the settings tweaked and still needed some fine sanding.
 

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Re: Resize a STL File For Me
« Reply #134 on: August 15, 2024, 01:27:07 pm »
I have tried Slic3r before.
Just looking at it again, I see on the tab for 'Printer Settings' -> 'Extruder 1' there is a Min and Max layer height.
The default that comes up for me is Min = 0.15mm and Max = 0.3mm.
Change the Min = 0.08mm  (or 0.04mm for an extreme case).

Also on the 'Print Settings' -> 'Layers and perimeters', you can try the 'Use adaptive slicing' option.
(You could temporarily change the Min=0.04mm and Max=0.2mm from before just for the knob print.)

Overall, you will never get a perfectly smooth surface.  Not sure of any technique for smoothing TPU.
« Last Edit: August 15, 2024, 01:32:11 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #135 on: August 15, 2024, 01:50:07 pm »
Quote
Overall, you will never get a perfectly smooth surface.  Not sure of any technique for smoothing TPU.

I agree on never getting it perfect, and, for a $300 printer, I don't expect perfection.

As for smoothening the surface, the only idea I had for TPU was maybe forming a metal cup, laying the knob in it, and heating with a heat gun. Most likely it needs better control and will just distort more than just the surface.
 

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Re: Resize a STL File For Me
« Reply #136 on: August 15, 2024, 08:52:58 pm »
Added additional parsing for Slic3r g-code output.

See above:  https://www.eevblog.com/forum/3d-printing/resize-a-stl-file-for-me/msg5605071/#msg5605071
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #137 on: August 16, 2024, 12:45:03 am »
Using FreeCAD v21, I figured out a few things such as how to tinker with the D shaft hole, but I can't figure out how to increase the dip on the face.

Not sure why FreeCAD isn't clicking with me.
 

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Re: Resize a STL File For Me
« Reply #138 on: August 16, 2024, 10:55:05 am »
The knob port to FreeCAD 0.21 is pretty messy.
I re-made it in the spirit of version 0.21 (attached).
Also attached is an annotated screenshot of the FreeCAD tree.

Generally, there are three sketches to define the knob:
  1) The overall knob blank (Sketch) which defines a vertical profile: height, width, depth, top dimple and outer edge
  2) The hole for the D-shaft (Sketch002)
  3) A flute vertical profile (Sketch003) which is pedded and then 12 instances via polar array

The top dimple/dip is defined by an arc in (Sketch) for the knob blank
« Last Edit: August 16, 2024, 01:12:09 pm by MarkF »
 

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Re: Resize a STL File For Me
« Reply #139 on: August 16, 2024, 01:38:44 pm »
... but I can't figure out how to increase the dip on the face.

This is how the basic knob is created with Sketch then Revolution:
Just decrease the height of the line along the z-axis (you're changing the arc endpoint, not its radius).

2340969-0

If you mean the flute depth, that's done by positioning Sketch003 and its V-shape angles:
In Sketch003, the distance from the origin to the profile point is specified.
  Sketch003 -> Pad -> Fillet -> Array -> Cut

2340977-1 2340983-2
« Last Edit: August 23, 2024, 12:20:18 pm by MarkF »
 

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Re: Resize a STL File For Me
« Reply #140 on: August 22, 2024, 10:00:22 pm »
Hours of FreeCAD 0.20 Tutorials demonstrating advanced drawing techniques for those interested.

  https://www.youtube.com/playlist?list=PLWuyJLVUNtc0UszswD0oD5q4VeWTrK7JC

(At the time of this posting, the tutorials are based on the previous FreeCAD version.  Newest version is 0.21.2)

'Mangojelly Solutions' has several other playlists of FreeCAD. 
IMHO his tutorials are some of the best I've found.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #141 on: September 22, 2024, 01:00:35 pm »
Does a way exist in G code to change the layer height on a specific layer range?

The knob prints fine with 0.3mm layer height and looks good, but the face is sloppy. The dip on the face isn't noticeable (I'm going to tinker with the depth in FreeCAD) and the face isn't smooth.

Printing the whole thing in 0.12mm causes the printer to jam - I've already discussed this issue in another thread and know/understand the reasons - but don't have much time to fiddle with the printer. I'd like to print the whole knob at regular layer height and then when it prints the face, start a short layer height.
 

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Re: Resize a STL File For Me
« Reply #142 on: September 22, 2024, 01:49:55 pm »
G-code isn't that high level.  What gets sent to the printer is just a bunch of sequential XYZ moves at a specified speed and extrusion rate (including zero and negative for retracts) + some other stuff for temperature and machine control.

Changing the layer height, infill density or other slicer parameter is a slicer function.  Some slicer software can slice different regions differently or even dynamically vary the parameters layer by layer, others cant.
 

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Re: Resize a STL File For Me
« Reply #143 on: September 22, 2024, 02:03:09 pm »
Interesting.

I assumed the layer height was part of "speed" and amount the G-code tells the Z axis to move. Guess G-code doesn't play as much of a role as I thought.

I had one successful print with 0.13mm layer height, but even with that, the face wasn't close to smooth.

It seems more that the TPU gets dragged around a bit before it cools due to it being elastic type, so trying to get finer details on the knob face is harder.
 

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Re: Resize a STL File For Me
« Reply #144 on: September 22, 2024, 05:38:20 pm »
G-Code just tells the printer how to move.
The real work is done in the slicer software.

I use PrusaSlicer (and I'm sure Cura also) has variable layer height.  You would need to see if your slicer has that capability and how to configure it.  If so, I would print the lower part at 0.20mm and the top at 0.08mm.  If not, just print the whole knob at 0.08mm and find a good book to read   :-DD

If you haven't already, cut your print speed way down.  At least 25% to 50% of you PLA print speed.

FYI.  The G-Code is just a text file.  Open it in a text editor and explore.
        Reference:  https://marlinfw.org/meta/gcode/
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #145 on: September 25, 2024, 03:33:58 pm »
Still uncertain I understand the difference between "groove" and "revolution".

Long story short, I wanted a 3/8" acorn nut cap (i.e. no threads). Last night I tinkered with making one using revolution (groove is still confusing to me).

I made a horizontal line, up a bit, over a bit, and down to the same horizontal line. This made the "wall" of the nut". One vertical line on the Z axis, and joined the vertical lines with a three-point arc (one arc for the outside and one arc to make the inner wall). After I performed a revolution and it was what I visualized.

I'm uncertain what a "groove" can do that revolution can't.
 

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Re: Resize a STL File For Me
« Reply #146 on: September 25, 2024, 03:34:55 pm »
Where do you come up with these oddball layer heights?

I think I mentioned this before...  I recommend you use a multiple of 0.04mm layer heights because of the pitch of your lead screw and they do not require a fractional turn of the stepper (which it can't do). 
(ie.  0.08mm, 0.12mm, 0.16mm, 0.20mm, 0.24mm or 0.28mm.  IMHO: layer heights outside of these are too small or large for a 0.4mm nozzle).
 

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Re: Resize a STL File For Me
« Reply #147 on: September 25, 2024, 03:38:39 pm »
Quote
difference between "groove" and "revolution".
just a guess but  could it be grove cuts out  the shape around an axis whilst revolution builds
 

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Re: Resize a STL File For Me
« Reply #148 on: September 25, 2024, 03:44:20 pm »
Still uncertain I understand the difference between "groove" and "revolution".

If you're asking about the two different tools, the 'revolution' is an additive action while the 'groove' is a subtraction action.

There is a 'Fasteners' tool bench for making bolt and nut threads.  Can't remember if it's one of the workbench you need to add or if it's there by default.  Goto Tools > Addon Manager to install it.  Another interesting workbench is the 'Assembly 4' which allows you to attach bodies together into movable parts to see the animation.
 

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Re: Resize a STL File For Me
« Reply #149 on: September 25, 2024, 03:49:53 pm »
There are always multiple ways to skin-a-cat.
You can make a body with a revolution of the shape you want to remove and then use it as a cutting body to remove it from a second body.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #150 on: September 25, 2024, 03:52:48 pm »
Quote
Where do you come up with these oddball layer heights?

Were you referring to me?

If you mean the 0.3mm height, that's the default in my slicing software and what I've used. As for the 0.13mm height, I didn't remember if the suggestion was 0.12 or 0.13, but I didn't realize multiples of 0.04mm was important. Maybe I even used 0.12mm and thought I used 0.13mm. Again though, I didn't realize multiples of 0.04mm was important until now.

Quote
If you're asking about the two different tools, the 'revolution' is an additive action while the 'groove' is a subtraction action.

Yes, that's what I'm asking about. Let's say I wanted to make diagonals, not necessarily threads, just  45 degree angles all connected together. I could draw a horizontal line, go up 45 degrees to the left, 45 degrees to the right, etc... draw a line back to the z-axis, and down to the 0,0 point. Now perform a revolution and I have the same as I would with groove (or believe I would).

Using 'groove' is still an uphill battle for me due to not grasping the whole tree structure. I create a sketch, then a pad, then another sketch, etc... I can follow the 1-2-3 steps, but I don't grasp the whole concept.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #151 on: September 25, 2024, 04:05:34 pm »
All you need to do is create a body, then a sketch of the profile, and do the revolve.
Note:  You can't cross the axis you're going to revolve around or it will fail.

Watch this:
  https://youtu.be/eP_pMWu25tM?list=PLWuyJLVUNtc0UszswD0oD5q4VeWTrK7JC&t=540
« Last Edit: September 25, 2024, 04:07:31 pm by MarkF »
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #152 on: September 25, 2024, 04:11:56 pm »
It would behoove you to watch his entire FreeCAD series.

   https://www.youtube.com/playlist?list=PLWuyJLVUNtc0UszswD0oD5q4VeWTrK7JC 

It's a serious commitment of time but well worth it.  It took me about four days to watch.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #153 on: September 25, 2024, 04:53:07 pm »
Not crossing the axis makes sense.

I'll have to set aside time to watch the videos. Typically if I don't grasp the concepts or the foundation, I tend to not retain the information well. Hence why I keep getting stuck on basic concepts, however, I know what needs to be done in order to create a part based off a mental image.

3D modeling I grasp. I've explained the basic concepts to friends when I've printed something and they stare at me like I have three heads, but I think the tree structure is what throws me for a loop; especially when I view designs by others.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #154 on: September 25, 2024, 05:20:25 pm »
I can't say that I have ever looked at someone else's FreeCad model.  I've always just watched them developing the model and seeing the process and not paying much attention to the tree structure.  I use the tree structure mostly to go back and edit previous parts of the model.  Not so much how it is built.

The only way I tend to learn is by 'doing'.  I do go back to videos to see how something is done and then doing it right away.  Just did a quick look and found that I've done 180+ models over the past several years.

I see that FreeCAD v1.00 is in release candidate and looking forward to seeing what's new.  Just the topological naming problem mitigation will be a welcome fix.  I'm always modifying something that adds a extra edge and breaking the whole model.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #155 on: September 25, 2024, 05:36:20 pm »
You're absolutely correct about learning by doing.

I don't necessarily follow the tree structure, but uncertain how to avoid it. In the case of this knob, the dimple on the face and the shaft hole needed to be changed. Ignoring that the tree names could be changed to make it more obvious, I find myself questioning why 'revolution' is above 'sketch'. Seems to me 'sketch' would be the parent part of the model and 'revolution' is a sub design (since it was done second).

When I made the acorn cap last night, I realized it was easier to delete the 'revolution' from the tree and return to the 2D 'sketch'. Prior I was looking at a series of constraints, lines, etc... that didn't make sense.

Again though, no idea why 'revolution' is sitting above 'sketch' in the tree structure, but just emphasizing why I get confused.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #156 on: September 25, 2024, 05:44:06 pm »
You have to pay attention to the indentation.  With the arrows, you can expand and contract tree branches.  The expanded revolution shows what was revolved.  The same with pads.  Expanding the pad shows what was padded.  etc.
The tree structure shows the sequence but also the sub-branches show the makeup of the higher branch.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #157 on: September 26, 2024, 08:29:08 am »
I was thinking of FreeCAD's tree structure and my understanding of it.
  • It is NOT a list of instructions for building a model.  As you would find in a set of Ikea shelves.

  • The tree shows the dependencies within the model.  As you go down the tree (at the same level), each item is dependent on the one above it.  Each sub-level/indentation contains the items that makeup that branch.  For example, the sub-level for a fusion shows what was combined or a cut sub-level shows what was cut from what or a compound shows all its pieces or etc.
Maybe that helps your understanding.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #158 on: September 26, 2024, 02:37:04 pm »
Quote
The tree shows the dependencies within the model.  As you go down the tree (at the same level), each item is dependent on the one above it.

This does help.

I think it's decades of seeing a tree structure for a Windows directory that's confusing. When I see 'sketch' under 'pad' I question: how can a pad exist when it was created after the sketch.

Interpreting the design from others is harder I think. Currently, as it has been, I can handle padding a 2D object and managing the tree somewhat. It's doing the fancier stuff like adding a second piece to a part that I don't grasp. Also, sometimes I've exported to a STL and I get garbage in the slicer software. I end up highlighting different things in the tree until I get a STL that makes sense; so I haven't understood what I need to highlight. In the past I believe I did a CTRL-A and got a junk STL, and then I've highlighted the last thing in the tree and got a good STL; but don't hold me to this as I don't remember exactly.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #159 on: October 28, 2024, 02:14:27 am »
I'm uncertain if I should start a new thread. If so, please let me know and I will.

The attached was created by me in FreeCAD v.21 and I have some questions. If I did this drawing correctly, I created the first sketch, padded it, added a 'map sketch to a face', added a sketch, added circles/holes, etc... Each time I wanted to add something to the initial 'sketch', I just clicked on that face and added a 'map sketch to face'. For the most part the tree structure began making a slight bit of sense, but did get confusing farther down the road.

I tried making it fancy by putting fillets at various points after I did a 'pad', but it restricted me on how much of a fillet I could add which I didn't quite understand; but assume it has to do with the constraints and the fillets being restricted.

After I realized the 90 degree bends on the outside (the outside of the U shape) should be rounded, so I attempted to add a fillet on the initial sketch but it wouldn't let me.

My thought is the fillets on the various areas were preventing the larger fillets, so I attempted to delete them, however, it wouldn't let me without telling me to also delete 'right side' and 'left side'. At this point things went downhill. Also, as usual, exporting it to an STL caused me to tinker with which stuff in the tree to highlight in order to get the correct STL.

My questions are: what (and I guess why) do I delete to have the ability to add fillets on the 90 degree bends?

Which stuff do I highlight to get the STL to export correctly and why? Exporting to STL has been a challenge for me as I don't understand the reasons the STL doesn't export correctly.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #160 on: October 28, 2024, 10:44:28 am »
The first problem is the filename.  No wonder it doesn't work.   :-DD

To get serious:
  • I would keep your questions all together in this thread.

  • Fillets and chamfers are tricky.  I suggest leaving them to the very last and not intermixed them throughout.  Sometimes you can do them within a sketch to help with the problem.  For example, you could have rounded the inside and outside corners in your first sketch when forming the 'U'.

  • Doing fillets and chamfers throughout creates extra edges and surfaces.  Therefore if you want to go back and modify something, the model may break and may be hard or impossible to fix.  (Save your work often.)  Trying to modify any of the dimensions can break the model if it creates or deletes an edge.  This is due to how FreeCAD names things internally.  You will learn as you go ways to help ease these restrictions.  FreeCAD 1.0.0 is an attempt to hopefully fix most of these issues.

  • The actual size of the fillet you can do depends on the geometry.  If while doing the fillet it reaches another edge in the model, the fillet will fail.  See the two red highlighted areas in your model as examples.

    2416455-0

  • The order you do the fillets and the edges selected can be important and may cause the fillet to fail.  I have had cases where I was unable to get what I wanted and wasted lots of time on compromises.  Hopefully, they will improve upon these tools in newer versions.

  • As for creating a STL file.  You can select one of two things from the tree to export.  Either the 'body' or the last operation 'Pad004'.  Whatever is highlighted will be included.  For instance, you could export just the 'U' shape with holes and no posts by selecting 'Fillet004'.  This is very powerful.  Allowing you to draw the entire part and printed it in pieces.  You can model how multiple bodies fit together during the design phase before printing them out.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #161 on: October 28, 2024, 01:45:36 pm »
Yes, the file name is what caused lots of my problems. :)

I named it JUNK because it was a copy of the original and would remind me it's a useless copy (unless I edited enough to be what I wanted).

You are correct about fillets being tricky. The inside of the U can't have fillets as it needs to have 90 degree bends, but thought to pretty the outside. I assumed, and it makes sense, that trying to add a fillet that imposes on something will cause issues. In some cases, I really don't understand why the fillet fails because nothing seems in the way. All I know is I add a larger number, not by much, and next minute I get either an error, the model vanishes due to an error, and/or I get a red explanation mark next to the name in the tree.

It seems enough room exists to add fillets to 'Sketch', but it just gave me errors. As mentioned, I thought it was the fillets I added when I clicked on a face and added a fillet. Since I didn't really understand, I just clicked a face, added a fillet, and looked to see if it was what I wanted. Other times I'll add some large number just to see what/where got affected, but large numbers results in the model vanishing on me. :)

At least you confirmed that the model can "break" easy when trying to tinker with stuff at the end like I did. I spent quite a bit of time trying to figure out why deleting something I added caused errors. No matter what I did resulted in the model being junk; unless I deleted everything and started from 'sketch'.

As for exporting the STL, you have mentioned the benefit of exporting individual sections in the past. I don't remember which item(s) from the tree I selected. Initially I tried CTRL-A, also 'body', and the last in the tree.

I assumed selecting "Pad004" would just export the one Pad rather than all the previous stuff. So it's always either the last in the list (in this case Pad004) or 'body'; unless I want an individual piece?
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #162 on: October 28, 2024, 03:05:52 pm »
When making selection for fillets and chamfers, you can select edges or faces.  Adding additional by holding CTRL key and clicking on more.  Clicking a second time removes the selection.  You can also change the selection from inside the tasks tab when it opens (the little button above the list that toggles between 'select' and 'preview').

I usually select for export from the tree.  You can select multiply pieces again buy holding the CTRL key.  What gets highlighted is what gets exported.  I have gotten errors and a blank STL in rare cases on complex models.  If you want to play it safe to begin with just select the desired body from the tree.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #163 on: October 29, 2024, 03:09:43 am »
Quote
I usually select for export from the tree.

Does a different way exist?

Earlier I was trying to delete the holes on the sides and rear, but leaving the padded knobs on the sides and top. For whatever reason, I could highlight holes for the right side, delete, and they erased. I tried the exact same steps for the left, and, even though they erased from the tree, the holes were still visible.

This is a design for something silly, but also a bit of playing for learning purposes. The reason for deleting the holes, or trying to delete the holes, was to place a pad on the left and right sides to show a center point. I created one on the right side, but, as mentioned, all hell broke loose when I attempted to tinker with the left.

Although this is a simple design and can just start over, I'd like to understand why all hell breaks loose should I have a complex design that I can't start over easily.
 

Offline Monkeh

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Re: Resize a STL File For Me
« Reply #164 on: October 29, 2024, 03:53:13 am »
The 0.04mm height is so the stepper motor doesn't have to do partial steps.

This is pointless as you have no way to ensure your position is actually a full step unless you entirely disable microstepping.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #165 on: October 29, 2024, 08:47:26 am »
Quote
I usually select for export from the tree.
Does a different way exist?
I believe you can click on the model itself to make selections.  It seems to be more trouble than it's worth.

Quote
This is a design for something silly, but also a bit of playing for learning purposes. The reason for deleting the holes, or trying to delete the holes, was to place a pad on the left and right sides to show a center point. I created one on the right side, but, as mentioned, all hell broke loose when I attempted to tinker with the left.
I can't answer to exact details.  In general, you could delete all of the pads and pockets (leaving just the sketches) and then select each sketch and pad or pocket each again.  You would need to be a little careful of the order that you redo them.  Not necessarily the order they appear in the tree.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #166 on: October 31, 2024, 03:16:00 am »
After many, many tries, and many minutes, I remain confused.

I wanted to create fillets on the outside of the U as mentioned. FreeCAD will not allow me, so I assume it's due to the fillets I created on the edges and/or the constraints on sketch x.

After changing the combination of which stuff I delete first, I always seem to break the drawing with all hell breaking lose.

I try deleting the fillets on the edges and it states I'm going to break the right (or the left) side drawing (I manually named these), I click yes since no other option exists, and an explanation mark is shown on the right/left side drawing.

I also tried deleting all the constraints on the holes, and that didn't eliminate all hell breaking lose.

What am I doing wrong or what did I do wrong when creating this drawings?

 

Online CatalinaWOW

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Re: Resize a STL File For Me
« Reply #167 on: October 31, 2024, 04:57:33 am »
After many, many tries, and many minutes, I remain confused.

I wanted to create fillets on the outside of the U as mentioned. FreeCAD will not allow me, so I assume it's due to the fillets I created on the edges and/or the constraints on sketch x.

After changing the combination of which stuff I delete first, I always seem to break the drawing with all hell breaking lose.

I try deleting the fillets on the edges and it states I'm going to break the right (or the left) side drawing (I manually named these), I click yes since no other option exists, and an explanation mark is shown on the right/left side drawing.

I also tried deleting all the constraints on the holes, and that didn't eliminate all hell breaking lose.

What am I doing wrong or what did I do wrong when creating this drawings?

Not an expert here, but I have fought fillets on many occasions and have learned a few tricks.  One that helps a lot is that if you right click on a fillet a menu comes up which includes "edit fillet".  Clicking on this brings the fillet creation box up where you can reduce the size of the fillet, which is the most common cure for me.  You can also uncheck edges until you find the problem edge (or edges).  Another thing that causes problems is geometry that only looks right, but isn't actually.  I don't see any obvious candidates for this type of problem in your model but its another thing to keep in mind.

One thing I am still wrestling with is keeping the coordinate systems of all the different pieces and parts of model properly associated.  It is quite possible to create something that looks right on the screen, or seems right logically where the program either has the coordinates tied together in a way you didn't really expect or understand, or just not tied at all.  Those with a proper CAD background probably laugh at problems like mine, but as a sparky used to the two dimensional problems of schematics and pwbs it can be confusing.  Following some of the YouTube tutorials on workflow can help here.  Some of the things that I saw as useless fluff as I started up the learning curve are starting to make sense now.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #168 on: October 31, 2024, 12:39:17 pm »
One thing I am still wrestling with is keeping the coordinate systems of all the different pieces and parts of model properly associated.  It is quite possible to create something that looks right on the screen, or seems right logically where the program either has the coordinates tied together in a way you didn't really expect or understand, or just not tied at all.  Those with a proper CAD background probably laugh at problems like mine, but as a sparky used to the two dimensional problems of schematics and pwbs it can be confusing.  Following some of the YouTube tutorials on workflow can help here.  Some of the things that I saw as useless fluff as I started up the learning curve are starting to make sense now.

I agree and I have gone back into a fillet selecting and unselecting to find the issue.

@bostonman mentioned earlier that when creating sketches, he would click on a face to use that as the reference.  As he intermixed fillets while creating the model, it is very possible that the reference face changed while he made edits.  I found that while referencing a face for a sketch is very inviting, I tend to avoid do it.  Instead, I will reference one of the axis to base the sketch on.  Afterward, you can through the data tab of a selected sketch change its attachment point.  For instance, you have a face 10mm above the XY plane you want to draw on.  You create the sketch on the XY plane (can leave it blank here), then exit and move the attachment point up 10mm, edit the sketch and finish drawing it.  In this manor it the face name changes, the model doesn't break.  One word of caution, the model can still break if face moves and you end up with multiple objects.  If doing a pad, you can always overlap the sketch reference a small amount.

Without more details, I can't comment on what might be going wrong.  But it suspect one of his reference faces has changed.  However, I did remove all of his pads and fillets and started over with just his sketches redoing the padding.  The holes on the middle section were a different size for some reason by doing that (didn't investigate why) and I don't know if all the pads were in the right direction.  But, the basic model was re-creatable from just the sketches.

Try doing the fillets with just edges and no faces as @CatalinaWOW suggested to see what is breaking it.  But rebuild the model without any fillets before you start to eliminated any other conflicts.  The current version FreeCAD may not be able to do what you want.  I recently did an airbrush holder that I never could fillet that way I wanted.

Or find a different way of drawing it.  Maybe drawing a U-shaped pipe with the fillets already built into the profile.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #169 on: October 31, 2024, 01:29:37 pm »
Okay.
After removing all the fillets and redoing the pads and pockets, I was able the create three different fillet sizes.  They are limited by the size and position of the holes and posts and the order of the fillets is critical.

In the original JUNK model the hole sizes in the sketches were bigger than the resulting pockets in the model.  I have no explanation for this.  It must be related somehow to the first three fillets but I don't see how.

2420127-0
« Last Edit: October 31, 2024, 01:41:27 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #170 on: October 31, 2024, 01:57:00 pm »
Quote
As he intermixed fillets while creating the model, it is very possible that the reference face changed while he made edits.

Although I have limited knowledge, if I understand correctly, this would make sense. I remember clicking on a face to create a fillet, and, when I saw it was created, thought this was good enough. Maybe at that point FreeCAD decided to link stuff together and why it wants to delete more than just a fillet (and holes).

I understand enough basic stuff to create something from scratch, however, as most can tell, going backwards is the challenge. Currently I understand enough to create a 2D model, pad it, and add to faces. Also, create a circular part. The fancy stuff I still haven't had a need to dive into nor know.

It seems v0.21 is much better than v0.16. In v0.21 which is the one I used for this, I was able to click on a face and then 'map sketch to a face', create a sketch, and then I could add. When I tried this series of steps with v0.16 last night, it kept giving me errors and realized v0.16 isn't worth the hassle to tinker with since a better version exists.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #171 on: October 31, 2024, 02:21:01 pm »
Quote
As he intermixed fillets while creating the model, it is very possible that the reference face changed while he made edits.

Although I have limited knowledge, if I understand correctly, this would make sense. I remember clicking on a face to create a fillet, and, when I saw it was created, thought this was good enough. Maybe at that point FreeCAD decided to link stuff together and why it wants to delete more than just a fillet (and holes).
 . . .
It seems v0.21 is much better than v0.16. In v0.21 which is the one I used for this, I was able to click on a face and then 'map sketch to a face', create a sketch, and then I could add. When I tried this series of steps with v0.16 last night, it kept giving me errors and realized v0.16 isn't worth the hassle to tinker with since a better version exists.

In the quote I was referring to your second statement where you have a face selected and create a sketch on it.  The new sketch has its base reference on the face and not one of the XY, XZ, or YZ planes.  When you later try to change an earlier object, you may destroy the face that was referenced, breaking the model.  Just be aware that it is easy to break these references.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #172 on: November 01, 2024, 01:00:05 am »
Quote
The new sketch has its base reference on the face and not one of the XY, XZ, or YZ planes.

Do I need to reference a plane?

I just clicked the face that I wanted to add and selected 'map sketch to face', then create sketch. When it allowed me to do it, I thought it was correct. :)
 

Online CatalinaWOW

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Re: Resize a STL File For Me
« Reply #173 on: November 01, 2024, 02:33:56 am »
Quote
The new sketch has its base reference on the face and not one of the XY, XZ, or YZ planes.

Do I need to reference a plane?

I just clicked the face that I wanted to add and selected 'map sketch to face', then create sketch. When it allowed me to do it, I thought it was correct. :)

Correct is tricky.  Tying a sketch to a face has benefits.  But if the face number goes away due to some later operation the sketch loses its roots.  The planes are always there.  Which is good.  But means you may have to jump through other hoops moving things around.

So correct depends on what you plan to do.  By the way the Part and Part Design workbenches do have differences and bouncing between the can cause still more "fun".
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #174 on: November 01, 2024, 02:43:53 am »
So what is the "correct" way to add?

Using my "junk" file as an example. I start off with making the U and pad it to 1". Now I want to add those little cylindrical pieces to the top.

The way I'd attempt is the way I mentioned: click the top plane, map sketch to face, add sketch (which I think would be auto named to sketch 2), and then treat sketch 2 like sketch.
 

Online CatalinaWOW

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Re: Resize a STL File For Me
« Reply #175 on: November 01, 2024, 03:52:12 am »
That is fine if you stop there.  But now imagine that you want to add cleats to the U.  By just padding a rectangle and merging it with the U.  Now the faces are different and it might make the reference go away.  But a different set of follow up operations would foul up a sketch tied to the base plane.


Again, I am a fumbler, not an expert, but the only way I see to know which way to go is to plan out the entire model, understanding all the pitfalls and decide then how to start.  Recognizing that if you change your plan in the middle you might need to go back and start over.  I am not proficient enough to do this so I do a lot of messing around a finding out, with quit a few dead ends and a few mysteries that have never been solved.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #176 on: November 01, 2024, 11:06:19 am »
There is no right or wrong here.

What you did is a correct thing to do.  What we are pointing out is that if, after the fact, you want to go back to an earlier step and make some change.  That change may break what you did in referencing the face.  There are ways to mitigate the risk of breaking the model while doing a modification.

You can reference one of the XYZ planes instead of a face.  However, this also has risks of breaking when editing older steps.

Only experience will determine which is best in any one situation.
Later, you will discover you can create custom reference planes in addition to the XYZ planes.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #177 on: November 01, 2024, 01:00:37 pm »
I fully agree more than one way exists to do something; not just with 3D modeling.

Hopefully I wasn't coming off as asking for the 1-2-3 step process. Obviously the way I approached this design worked and various ways to create this exist. When the design "broke", I was unable to understand the reason(s) why and that was the more frustrating part.

I can always delete everything and return to just a single 'sketch', but I always look at such problems knowing a time will come when something is more complex, greater precision is needed, etc... and question the correct way to do it now before I'm confronted with such issues.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #178 on: November 01, 2024, 01:27:47 pm »
I didn't think you were asking for a 1-2-3 step process.
And, I still don't know why your design broke.  Mostly, just guesses.

We're just pointing some of the pitfalls we have run across in our own designs and alternatives that may help you in the future.  I most cases it doesn't matter how you do the design.  The trouble starts raising its ugly head when you need to tweak the model.  Over simplified examples are your knobs and adjusting the dimensions of the hole for the D-shaft to correct for tolerances in the encoder and your 3D printer.  It's much easier to break a model if you need to add a hole or change a shape.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #179 on: November 01, 2024, 01:44:38 pm »
It's nice to know that my confusion isn't just me.

I'll tinker with it more just for fun, but think the fillets is what added a layer of complexity and why things break when I tweak. I thought my foundation was enough to build on, but, after watching some of those FreeCAD videos, I learned lots exist I never imagined.

It's a comforting feeling though knowing something can be created and printed which makes 3D modeling so much fun.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #180 on: November 01, 2024, 06:57:17 pm »
I was just sharing some new 3D designs for my model railroad.
Thought you might enjoy some more complex FreeCAD model examples:
(All the walls, roof, and furniture are their own 'body' in FreeCAD.)
   https://www.eevblog.com/forum/chat/model-trains/msg5697955/#msg5697955
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #181 on: November 03, 2024, 01:51:30 pm »
Wow, those are some great designs. Maybe you know FreeCAD better than you think. :)
 
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Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #182 on: November 27, 2024, 12:04:01 am »
I have another design that went off into left field.

Attached is something I made for a project. The larger square began as 3.55" and the width of the two forks were 1.5" along with two ovals on the sides with pockets.

I wanted to increase the square to 3.6" and decrease the width of the forks to 1.4". After about three-hours of trying to accomplish this due to constraints getting in the way, I was successful, but realized one of the ovals went off into left field.

After I went back to the original design to tinker with the pockets. I discovered if I made pocket two 0" depth and pocket one "through", then it made pocket two a hole too.

My first question: why is pocket one affecting pocket two?

My other question: why did the oval go off into left field and how to get it back?

I thought trying to map it to a sketch would help or switching planes, but I don't understand what is going on.

As always, I'm trying to understand things rather than have it done for me.
 

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Re: Resize a STL File For Me
« Reply #183 on: November 27, 2024, 02:28:56 am »
  • In your "I'm More Lost" file you once again discovered what happens when you wipe-out a sketches reference.  I suspect FreeCAD changed the sketches name while you were making changes.  Sometimes it's easier to redraw a simple sketch rather than fixing its reference.  You can make this model by only referencing one of the axis planes.  I've attached an example.

  • When making pockets, the sketch does NOT have to be on the surface.  It can be out in space as I demonstrated here.  Try changing the pocket to various distances instead of through all.  Also in your "I'm More Lost" file, you can see that your pocket is cutting into both forks.

    Review this video for "Understanding Pocket Types and Options"


  • In both files, the sketch used for padding is not totally constrained.  Although this is okay to through something quickly together, it's a bad habit to get into.  It's also a possible source of things falling apart when later being edited.

  • When constraining a sketch some things I noticed:  set opposite sides equal instead of their dimensions the same, set a line endpoint tangent to the axis instead of setting the distance to zero to attach a line to an axis.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #184 on: November 27, 2024, 04:50:00 am »
Sorry for the file naming. I was aggravated and named them out of being annoyed.

Am I suppose to select 'map sketch to a face' when I add something (in this case) an oval to make a pocket?

In the video you linked, he just clicked a face and selected 'create a sketch'. Maybe this is causing names/links to get renamed/break?

I never know how much to constrain. Usually I constrain lengths, I try making things equal so two sides move equally, etc... Eventually the design is full of so many constraints that I can't figure out which one is applied to which line(s).

Unless I haven't found it, I think being able to click on a constraint in either the constraint list or the image would help.

One minute I'm trying to change a line length and next minute fillets are giant reversed circles, some line changes length, a line goes off the main axis, etc...

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #185 on: November 27, 2024, 11:47:32 am »
I couldn't care less what your filenames are.  They just give me a laugh.   :-DD

First, there should be a toolbar in sketcher with all the constraints listed.  It may be shrunk a little if all your toolbars are on the same line.  You can re-arrange them to suit.  If the toolbar is not there, go to View -> Toolbars and turn it on.

2447279-0

I tend to avoid mapping a sketch to a face unless it's needed.  It's has been the most likely way I've broken my models.  If you have something selected when you create a sketch, FreeCAD will use the selection as the reference plane.  Otherwise, it asks you which XYZ plane you wish to use.  I have a great deal of difficultly in fixing the reference plane after the fact.

I try to totally constrain my sketches.  Mostly starting with things vertical and horizontal edges.  Then constraining the lengths and diameters.  While dragging points, those large reversed circles and flip-flopping can be minimized by having more constrained prior to dragging a point.  You want to continue until FreeCAD tells you that there is zero DOF's left and the sketch turns green.
« Last Edit: November 27, 2024, 11:52:39 am by MarkF »
 

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Re: Resize a STL File For Me
« Reply #186 on: November 27, 2024, 02:32:29 pm »
I tend to use sketches for complex geometry, which means LOTS of constraints.  Naming the constraints can help in keeping track of them.  Also a large, high resolution screen so you you can see and separate them more easily. 

For simple shapes like ovals and circles I tend to use simple geometry from the Part Workbench.  I know many folk recommend not doing that, but it works for me.  As always you have to keep track of the geometry references.  The Body concept in Part Design handles much of this and is the reason that approach is recommended.  So far I haven't done complex stuff like multi-cylinder engines or submarines that really benefit from the recommended approach
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #187 on: November 28, 2024, 12:27:22 am »
Quote
I couldn't care less what your filenames are.  They just give me a laugh.

Good to know, I'll keep up the good work. My PhD friend would name variables and such as 'dog', 'cat', etc... and I thought that was funny. Eventually I adopted it, so when I'm questioning a variable in something like an Excel spreadsheet, I'll use them.

The constraint list is visible on my screen. I do need to practice naming constraints as I go. Being able to click on a constraint and/or a line where it tells you the constraint number would help.

I'll also stop clicking 'map sketch to face' before adding a sketch. The concepts and planes I have an understanding of, but it's when FreeCAD (I assume no 3D modeling software comes without quirks) throws something off into left field, then I can't seem to connect my knowledge of X,Y, and Z planes, and what FreeCAD is torturing me with.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #188 on: November 28, 2024, 12:57:16 am »
The constraint list is visible on my screen. I do need to practice naming constraints as I go. Being able to click on a constraint and/or a line where it tells you the constraint number would help.

If I understand what you're saying, FreeCAD does do that.  All the constraints are listed in the 'Tasks' tab (mine is on the left bottom).  You can select one in the tab and it should get highlighted on the model.  The reverse is somewhat true also.  They are numbered at both places and you can delete one from both places.  I find it a little hard to select one on the model sometimes.

I have to check but I think some of them can be hidden.  Haven't really fleshed that out.
« Last Edit: November 28, 2024, 01:03:31 am by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #189 on: November 28, 2024, 04:01:15 am »
I'll have to check again.

I thought when I click one in the 'tasks' tab, it doesn't highlight the line in the drawing.

All the constraints can be hidden at once by clicking the eye, and believe individual ones too.

 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #190 on: December 08, 2024, 02:26:55 pm »
I have a few questions to (hopefully) get to another stage in learning/understanding FreeCAD. I know what I want to achieve, but not sure what terms to search for which makes it hard to search online.

To emphasize, I understand there is more than one way to do something and many tinker to achieve what they are trying to accomplish.

I don't necessarily have a particular project at the moment, but, to make my questions easier to visualize, let's say I want to make a box with two halves so the top can be removed and maybe four posts to use as legs. Again, this isn't an actual project, but the questions I have about FreeCAD are applicable to this example.

The main issue I keep having is: when I add a sketch (sketch 2) to the main sketch (sketch 1) so I can draw the circle for the legs, I can't work off the sketch 1 drawing. Meaning, I can't place a circle and then set constraints off sketch 1, I have to figure out where the lines are for sketch 1 and then set constraints off the X and Y axis.

Having said all this, my questions are:

Does a way exist to work off sketch 1 (it's visible, it's just unable to be 'touched' when in sketch 2.

When drawing the box, I'd start by making a square (or rectangle) and then padding it. How do I "cut" it to make it two halves, but also, the top (or bottom) half would need an inner lip to fit inside the other so they lock together eventually. So I'd need to work with one of the two sketches to add an inner lip, this is where being able to 'touch' sketch 1 would help.

Also, is there a way to set the distance between two curves? If I made the corners of the box a fillet, can I set the distance on the curves rather than the parallel lines? I find that when using fillets that the corners come out different lengths based on where you click on the lines. I end up trying to add constraints to them, however, all hell tends to break loose because it causes other stuff to fall off the deep end.

 

Online rteodor

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Re: Resize a STL File For Me
« Reply #191 on: December 08, 2024, 02:55:27 pm »
Does a way exist to work off sketch 1 (it's visible, it's just unable to be 'touched' when in sketch 2.

Yes there is: while in "Sketcher" use "External geometry" to select whatever you want to import in the current sketch. This can be a feature (dot, line, circle) from a previous sketch or body. Of course it has to be made visible before. It is not possible to import external geometry from another body, (at least not directly).

When drawing the box, I'd start by making a square (or rectangle) and then padding it. How do I "cut" it to make it two halves...

As far as I know in "Part design" workbench is not possible to work with more than one solid object. Cutting a body in multiple pieces is possible in "Part" workbench, for example, by subtracting a proper shape.

PS: I use an older version so some things might have changed in the meantime.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #192 on: December 08, 2024, 04:10:59 pm »
When drawing the box, I'd start by making a square (or rectangle) and then padding it. How do I "cut" it to make it two halves, but also, the top (or bottom) half would need an inner lip to fit inside the other so they lock together eventually. So I'd need to work with one of the two sketches to add an inner lip, this is where being able to 'touch' sketch 1 would help.

No.  You don't approach it that way.  You do it with two bodies.  One being the top half and the other the bottom half.  The two bodies are easier if they are both referenced the same way.  (i.e.  Pick a corner for (0,0) or I tend to make them symmetrical around the center of the box and specify a length and width.)  I also pick the divide between the top and bottom half as the XY plane.  The top and bottom height does not have to be symmetrical.

I just re-made a box for my handheld railroad throttles.  Looked at the attached for a blank box as an example.
You can make one of the halves 75% transparent to see how well they fit together.

Quote
Also, is there a way to set the distance between two curves? If I made the corners of the box a fillet, can I set the distance on the curves rather than the parallel lines? I find that when using fillets that the corners come out different lengths based on where you click on the lines. I end up trying to add constraints to them, however, all hell tends to break loose because it causes other stuff to fall off the deep end.

I would need an example, but you can probably use a tangent constraint so that the ends of the curve are 90 deg relative to the center.  Or you can use the vertical and horiz. constraints on the ends of the curve and the center point.  Also, if you're doing curves from within a sketch, you can use "End points and rim point" instead of "Center and end points".  Also, you can trim a corner using the "Constraint preserving sketch fillet" which leaves the corner as reference.

If your sketch falls apart, try constraining other parts of the sketch before the constraint that blows it up.  FreeCAD doesn't know what to do when a radius moves from the inside of a curve to the outside for example.  It tries to draw the curve the opposite direction.  Trying to draw close to the end dimension size helps.  Don't draw ten times bigger than actual size and expect good result scaling it one dimension at a time.  Other times it's better to draw some disconnected pieces and then with the "Coincident constraint" tied two points together after dimensioning.

I don't use the grid much anymore.  It might help you with an inch grid to get your zoom nearer to actual size before starting a sketch.
 

Online CatalinaWOW

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Re: Resize a STL File For Me
« Reply #193 on: December 08, 2024, 07:07:59 pm »
First I will endorse all of MarkF's suggestions.  And add a methodology which helps getting the scale right in a great many cases.

Take a picture of whatever you are matching up with.  This doesn't help if both sides of all interfaces are from the ground up designs, but usually you are trying to make something that fits into the real world.  Sometimes a scanner is an easy tool for getting the picture, other times your cell phone or digital camera works.   Having a ruler (scale) or at least something of known dimension helps immensely.

Import and properly scale your picture and then draw your sketch over the photo.  FreeCAD 0.22 and 1.0 do this differently than earlier versions (much easier), but in either case there are excellent YouTube tutorials on how to do this. 
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #194 on: December 08, 2024, 11:12:11 pm »
I'll try all those suggestions.

I shouldn't have sent the message before giving more thought to all the questions I came up with over the weekend because I had one more.

When I use AutoCAD and need to do something such as add something that's both horizontal and vertical X units away, I'll draw a line from point A, go across X units and then up/down Y units. After I return and delete those lines.

Although maybe an easier method exists, it works for me, but is a pain to return to delete lines.

In the case of FreeCAD, I wanted to add something X and Y units away from a point, and did the same thing. I drew a horizontal line then a vertical, horizontal and vertical length constraints, added what I wanted, and then deleted the lines.

Does an easier way exist or is this the best approach?

My assumption is that I may throw FreeCAD off into a loop if I add lines and then delete them, but it didn't seem to have a negative affect.
 

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Re: Resize a STL File For Me
« Reply #195 on: December 09, 2024, 12:20:23 am »
Everybody has their own way of seeing things.

In FreeCAD the concept of construction lines may help.  Draw the lines as you have, and identify them as construction lines.   They then won't be part of the model, though they are part of the file (that distinction is subtle, but important).  You won't need to, and possibly would prefer not to erase them.

When I am doing something like that I often just adjust the position coordinates of the object appropriately, or sometimes use the transform tool.

Both of these approaches can lead to a problem.  Due to rounding of the screen display the point you placed may not be identically equal to the location of an adjacent part.  The same to perhaps several decimal places, but not equal.  Whether this causes a problem or not depends on what downstream modifications you make.  A more robust approach is the external geometry approach mentioned above along with using the appropriate constraints in Sketcher (same, tangent or whatever).
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #196 on: December 15, 2024, 03:42:57 pm »
3D modeling isn't as easy as I initially thought.

I also have a 2D mindset where I draw a 2D box or whatever and pad it, so my lack of creative mind hinders me.

Each time I try to set a line to an external geometry it just gives me a circle with a line through it each time I hover over a line.

Attached is a picture of a concept I've struggled with. It's two shapes, but ideally it will be more elaborate such as the cylinder being a slot to hold a part and the rectangle being a mounting bracket.

The concept I've struggled with is: I need to make the rectangle "touch" the cylinder outside so it's one whole part. Both pieces will be different shapes/sizes, but they need to be one complete part in the end. My thought is to make the outside of the cylinder a geometry line and then use the tangent constraint to "touch" the two.

The other issue: the rectangle needs to be (for this discussion) centered. When I draw the rectangle, it starts off at 0.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #197 on: December 15, 2024, 04:46:09 pm »
Not sure I grasp what you're trying to do here.

Maybe describe the drawing steps you're taking.

Notes:
 1)  To reference external geometry, the geometry must be in the same body.
     Not exactly.  There are other ways but I don't want to make it too complicated right now.

 2)  Just having the rectangle tangent with the cylinder is NOT good enough. 
     FreeCAD will see them as two objects which is not allowed at this time.
     They will have to overlap a little.  Even as much as 0.001" would be enough.

I'll wait till I understand better what the end product is to be.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #198 on: December 15, 2024, 05:00:32 pm »
The drawing I provided is a rough idea to show what I was trying to learn, but let's say it's a cup holder with a wall mounted bracket.

The cylinder would be the cup holder part and the rectangle will be shaped into some sort of bracket. Both parts need to be as one, but, in my drawing, I just showed them with a large space for example purposes.

Can I just move the rectangle close to the cylinder (or overlap as you stated) and that will become "one" complete part? I assumed FreeCAD and slicing software would treat them as two separate pieces.

Also, as mentioned, I'd like to understand how to move the bracket (rectangle in this case) so that it's centered and not starting at point 0. Currently it's at the open end of the cylinder, but I'd like to understand how to make it so I can position the rectangle say halfway between both ends of the cylinder.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #199 on: December 15, 2024, 05:33:30 pm »
Something like this?

2462251-0

Assume the cylinder is sitting on the XY plane.

Method 1:
Draw the bracket on the XY plane also and pad it to desired thickness.
Select the sketch with the bracket and change the Z attachment point in the "Data" tab.

Method 2:
Draw the bracket in the XZ plane at the desired profile.
Then pad the sketch with "Symmetric to plane" option selected to the desired width.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #200 on: December 16, 2024, 01:42:30 am »
Quote
Select the sketch with the bracket and change the Z attachment point in the "Data" tab.

I tinkered with this one and didn't realize that menu (Data) existed; or I never really paid attention. I'll try your other method in a bit.

So, if I make the cylinder a radius of 1" with a wall width of 0.1", the rectangle offset 1.1", that would place the rectangle on the outside of the cylinder (if I explained this wrong, all I meant was to place the edge of the rectangle so it touches the outer wall of the cylinder)

Is this all FreeCAD (and the slicer) needs to make the two shapes one complete part? I understand the two are "touching" but is it enough for it to make one whole part that won't print with a "space" between the two shapes?
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #201 on: December 16, 2024, 03:12:59 am »
So, if I make the cylinder a radius of 1" with a wall width of 0.1", the rectangle offset 1.1", that would place the rectangle on the outside of the cylinder (if I explained this wrong, all I meant was to place the edge of the rectangle so it touches the outer wall of the cylinder)

Is this all FreeCAD (and the slicer) needs to make the two shapes one complete part? I understand the two are "touching" but is it enough for it to make one whole part that won't print with a "space" between the two shapes?

Try it.
I think you will find that when you try to pad the rectangle it will fail.
Even the smallest fraction of an overlap will fix it.
When printed with such a small intersection, the joint will be very weak.
In the one I did the screen-capture on, I made the rectangle intersect with the inner wall instead of the outer cylinder wall.  You will want some structural strength to the joint will you not??
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #202 on: December 16, 2024, 03:37:03 am »
Quote
You will want some structural strength to the joint will you not??

You are absolutely correct and I agree.

I didn't give thought to them "touching" and not having structural integrity. I focused on the rectangle overlapping and deforming the rectangle. Yes, it should be buried to a degree and then tweak the rectangle to accommodate the buried section.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #203 on: December 18, 2024, 12:38:09 am »
Either FreeCAD is trickier to use than most programs I've tinkered with and learned (to a degree), or I'm just not made to learn 3D modeling.

I'm not having any luck trying to create 'external geometry'. I've looked on the FreeCAD website and have gone through the steps. It seems straight forward, click the 'ext geometry' button, click on a line or whatever, etc...

Each time I follow them I get the cross hair, but, when I hover over a line, I get the circle with the cross through it.

 

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Re: Resize a STL File For Me
« Reply #204 on: December 18, 2024, 01:22:01 am »
 : Don't give up.  I have had problems learning new software, and then at some point I understand the "world view" responsible for the software organization and it suddenly all makes sense. 

As an example I started spreadsheets on Lotus 123, the made an easy switch to Quattro (the Borland low coast 123 clone) but when Excel came along I was flummoxed.  Could make no sense of how to create charts and graphs.  The one day it clicked and never looked back
 

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Re: Resize a STL File For Me
« Reply #205 on: December 18, 2024, 01:45:27 am »
Quote
Either FreeCAD is trickier to use than most programs I've tinkered
Dont know if its trickier,but i just couldn't get on with it,tried following sevral tutorials but buggered if i could get me head around it.Ended up giving up and going else were.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #206 on: December 18, 2024, 04:09:09 am »
Quote
but when Excel came along I was flummoxed

I had just converted from my C64 to a PC when I first came across Excel. It booted, I saw a bunch of rectangle blocks, and didn't know what it was used for. Then I was with a friend and he opened Excel to show me what it did. From there, I just figured out how to connect the dots by applying formulas and stuff. Although, till this day, I don't use all the features, don't need to, and don't really know what exists that can benefit me.

You're correct, don't give up, which I'm not doing. I think FreeCAD is a good program, especially since it's built from a group and free. Seems like it has quirks that maybe the more experienced (or maybe developers) know to avoid while the common user deals with the quirks in unorthodox methods.

In most cases, designs or practice designs I tinker with in FreeCAD result in trying to fix some error/quirk rather than learning new techniques to create more elaborate designs.

Quote
Dont know if its trickier,but i just couldn't get on with it,tried following sevral tutorials but buggered if i could get me head around it.Ended up giving up and going else were.

I wouldn't give up unless you have a more expensive program like Solidworks. Otherwise, from the few CAD programs I've seen/used, I think FreeCAD is quite good and powerful.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #207 on: December 18, 2024, 05:25:02 am »
Never mind, think I grasp the concept now.

I was trying to make a line a geometry line from the start rather than waiting until I added a sketch. Plus, I wasn't clicking on a face, I was just adding another sketch.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #208 on: December 18, 2024, 11:08:41 am »
Never mind, think I grasp the concept now.

I was trying to make a line a geometry line from the start rather than waiting until I added a sketch. Plus, I wasn't clicking on a face, I was just adding another sketch.

You DO NOT need to select a face for this to work.
Mapping a sketch to a face was a misleading example.

You just need to be in a sketch to reference a line or point from another existing sketch.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #209 on: December 18, 2024, 01:00:56 pm »
Here is a more detailed video on the sketcher and using construction geometry and external geometry.
It also shows techniques for doing constraints.

https://youtu.be/sXPapS0WLgk?t=870

An "external geometry" example with two sketches and NO map to face as in your example.
However, I recommend watching the entire video.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #210 on: December 18, 2024, 02:11:59 pm »
I'm using 0.16 (I have 0.21 on a laptop) and the steps in the video don't work in 0.16. The same results occur: I get a circle with a line through it.

I don't use 0.16 often, usually 0.21, but sometimes rather than pull out the laptop, I'll tinker with 0.16.

Later I'll try the same steps on 0.21.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #211 on: December 18, 2024, 02:40:02 pm »
Now I see why, in your example video, he mapped the sketch to a face when he created it.
In FreeCAD 0.16, you can ONLY reference external geometry from the object you mapped to.

If you first draw a rectangle and pad it into a cube, you can then map a new sketch to any of the cube faces.  Within that new sketch you can now pick external geometry even from other faces of the cube that you didn't map the sketch to.
Very restricting.
 

Online themadhippy

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Re: Resize a STL File For Me
« Reply #212 on: December 18, 2024, 04:03:14 pm »
Quote
I think FreeCAD is quite good and powerful
No doubt its is  but it don't seem to be compatible with my brain

Quote
I wouldn't give up unless you have a more expensive program like Solidworks
funny you mention solidworks ,my weapon of choice comes from the same stable,pity its online only but for the price i can put up with that.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #213 on: December 18, 2024, 11:57:02 pm »
I may have mentioned in either this thread or others that I usually prefer using software that's used in industry. It allows me to use it if needed and/or be able to talk the same language with others.

Wanting popular (and expensive) software comes at a cost. Years ago I "obtained" such expensive software (Solidworks, Altium for PCB layout, etc...). Now I'm trapped because I need my old PC to run such software due to not having the same connections to get new versions.

When I want to do something secure, I'll use my work laptop. Whenever I look into a new PC, I think about trying to get MS Office along with other pieces of software. I can run a virtual XP within Windows 10 on a new PC, but I've been down this road. The results are spending more time messing around with issues than using the old system.

Anyway, alternatives exist for MS Office, but find having the same software used in industry can be quite useful.

With this being said, FreeCAD is a great alternative to blowing $15k (?) on a license for Solidworks. Due to my main PC running XP (for reasons listed above), I'm stuck with 0.16. My laptop runs Win7 and I'm stuck with 0.21.

I agree though, for some reason it doesn't seem to be compatible with my brain either. The only 3D modeling experience I have (besides seeing others use Solidworks) is Google Sketch. If you think FreeCAD isn't compatible with your brain, then you haven't experienced the frustrations of holding your breath praying even the simplest model looks the same in the slicing software.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #214 on: December 24, 2024, 11:26:52 pm »
I have a few more FreeCAD questions.

First off, using geometry has opened a whole new world and now makes more sense. Although I haven't had any "real" designs, I've been tinkering with different concepts using geometry.

Two things that continue confusing me is in the attached two pictures (although this seems like I should have figured out this problem by now on my own).

In 'Design 1' I made a rectangle with a circle, 'padded' it, and the result was a block with a hole. Wanting to make another hole (used a hexagon to distinguish between the two for purposes of discussion) left to right, I clicked the planer face on the right, added a sketch, and added a hexagon (I 'padded' it so it stood out for my question but want it as a hole that goes all the way through).

For whatever reason, I can't make this a hole that goes all the way. FreeCAD 0.16 doesn't have a 'hole' option, but v0.21 does, however, it doesn't seem to make the hexagon a hole. What am I doing wrong?

In 'Design 2', I made a simple circle (the front part that is highlighted), cut it to make it a semi-circle, and padded it. Now, the (what I consider) more difficult question I haven't been able to solve: how do I mess with the padded part (the top curved black part or even the underside curved part)?

If I click on it and 'create a sketch', it gives me an error that it needs a planer face as a support for a sketch.

Things I'd like to do would be: curve/fillet the corners rather than have 90 degrees, and then just adding something to the non-planer (?) face.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #215 on: December 25, 2024, 12:09:22 am »
Design #1:
  The "Hole feature" is really for making threaded holes with various characteristics.  I would classify it as an advanced capability.  For making basic holes, use the "Pocket feature".  It just makes a simple hole.  You can select the length, direction, symmetric, taper.  One of the last videos I linked to showed most of the options and how to use them.

Design #2:
  This is where things get complex in a hurry.  At a very basic (limited) level you can draw a sketch on one of the XY, XZ, or YZ planes to pad or pocket something with the techniques we've already discussed.  These will NOT be perpendicular to the curve.  If you want something perpendicular, you will need to learn how to create datum lines, planes and local coordinate systems.  I'll see if I can find a tutorial for using datum planes.  You may want to review the tutorial playlist I linked earlier for other advanced techniques using curved surfaces.

  You should be able to select any of the edges to fillet or chamfer as it is unless you want some special edge shape.


For future reference:
  I'm going to assume all your questions are referring to version 0.21.2 unless you otherwise specifically state that the question is for another version.  And since I'm running Win7, I will be staying with version 0.21.2 for the for see-able future.  I believe I actually started with version 0.19.  I have to go try things for 0.16 questions.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #216 on: December 25, 2024, 12:38:01 am »
Here's a tutorial of tricks to add features to a curve without using datum planes.


 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #217 on: December 25, 2024, 02:25:46 am »
Quote
For making basic holes, use the "Pocket feature".

I tried different features and used pocket too. Prior to typing this reply, I checked again to make sure I'm not explaining this wrong. After using the 'pocket' feature, the hexagon does show throughout all (I selected 'through all').

After, when I'm looking at the tree structure, I notice 'pad' for the rectangle that I did in the previous step is greyed out indicating it's 'hidden'. After I make it visible, the hexagon vanishes; but I can still see the outline of where I placed it on the planer. As a result, I assumed that using 'pocket' wasn't correct since I couldn't get the entire tree structure to show everything as visible and still get all the through holes.

Quote
And since I'm running Win7, I will be staying with version 0.21.2 for the for see-able future.  I believe I actually started with version 0.19.  I have to go try things for 0.16 questions.

I tinker with both versions. v0.16 more common since it's on my PC, but I confirm any anomalies on v0.21 before posting a question.

Quote
Here's a tutorial of tricks to add features to a curve without using datum planes.

Wow.... I don't know what is more impressive in that video, making the groove throughout the curve or adding the mounting holes to non-planer surfaces.

I wasn't expecting such an involved process adding something to a non-planer surface.

Whenever I watch one of these videos, my confidence level in learning FreeCAD (or 3D modeling) gets knocked down a level. So far I've mastered the art of making a cube and thought I was ready for the advanced course. :)
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #218 on: December 25, 2024, 03:13:19 am »
Quote
For making basic holes, use the "Pocket feature".

I tried different features and used pocket too. Prior to typing this reply, I checked again to make sure I'm not explaining this wrong. After using the 'pocket' feature, the hexagon does show throughout all (I selected 'through all').

After, when I'm looking at the tree structure, I notice 'pad' for the rectangle that I did in the previous step is greyed out indicating it's 'hidden'. After I make it visible, the hexagon vanishes; but I can still see the outline of where I placed it on the planer. As a result, I assumed that using 'pocket' wasn't correct since I couldn't get the entire tree structure to show everything as visible and still get all the through holes.

What you're experiencing is just the visualization of the steps you selected to be visible.  When more than one item is visible, they are all drawn on top of one another.  If you watch the tree as you create a model, you will see that FreeCAD will hide previous steps as you create new ones.  There is also the advantage that you can hide newer steps to see stages of the development (or as I mentioned before, you can actually export a previous step).  In your 'Design #1' you can export the block with both holes or export it with just the round hole WITHOUT modifying the model.

I have done complex designs where I've seen multiple things overlaid and had a difficult time even identifying them. It keeps you on your toes.  ;)
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #219 on: December 25, 2024, 04:11:44 am »
Quote
I have done complex designs where I've seen multiple things overlaid and had a difficult time even identifying them. It keeps you on your toes.  ;)

I can't imagine dealing with complex designs. My tinkering is simple and yet they become confusing.

Exporting can still get confusing as I hold my breath each time I export something. It's been explained in this thread plenty, but it hasn't clicked in as to why a CTRL-A doesn't export everything whereas I need to click (in this current tree) pocket (for the hexagon) which is the 3rd last in the tree under pad-sketch (for the rectangle) and the last (4th item) is sketch1 (the hexagon) - see my screen shots with file names explaining.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #220 on: December 25, 2024, 01:28:21 pm »
Apparently you still see the tree structure as a list of all the parts of the model. 
It is NOT.
Only multiple 'Bodies' make up individual parts.  But even still, you would export/print each body one at a time.

The tree is a list of each stage of the design process.  It's like a cooking receipt.  You do this, and then this, and last of all this.  It's the construction order.  (In complex designs that's not exactly true.)
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #221 on: December 25, 2024, 03:45:20 pm »
I'll try getting that out of my head that the tree is a list of parts.

Sometimes I export a model (to STL) and I don't see fillets in the slicing software, so I'm baffled. Then it seems to exist when I view the individual layers in the slicing software, but they are on such small faces that I don't know if they don't appear due to size or don't exist.

At this point I say, whatever.... just print the thing and attribute not seeing fillets to the slicing software; but also keep in the back of my mind I don't understand the tree enough to figure out if I'm not selecting something correctly when I export.

Since the tree is a list of stages in the design, then it makes sense selecting the last item in the list (pocket in this case) will export everything.

Using CTRL-A in the tree seems like that should also export everything, but obviously doesn't.

If I'm having this much "fun" now with a rectangle and two holes, can't wait until I step up a notch and 3D model an internal combustion engine. :)
 

Online rteodor

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Re: Resize a STL File For Me
« Reply #222 on: December 26, 2024, 02:58:34 pm »
Using CTRL-A in the tree seems like that should also export everything, but obviously doesn't.

If I'm having this much "fun" now with a rectangle and two holes, can't wait until I step up a notch and 3D model an internal combustion engine. :)

One thing it seems its not well explained and made clear in any FreeCAD tutorial I saw, but it is a must to know: everything, everything relates to your selection in the Model tree.. When something does not appear to make sense check what is the current selection until this habbit gets into your bloodstream.

To export everything, best is to select the body. That will export whatever its the last step in the tree - and that is usually what you want to print.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #223 on: December 26, 2024, 04:16:57 pm »
I can't remember what slicer you're using.  But, the slicer should not loose any part of your model and, if you exported it correctly, any fillets should exist in the STL.

However, the slicer may not be able to reproduce, and may not display, tiny fillets due to choices you made in configuring the slicer.  For very tiny fillets and other details, you will at least need to select a fine layer height or a different print orientation.  If you have a large layer height, small details will be blown out.  It's like trying to read a car license plate in a picture with a low resolution.  You just can't see the detail.

A lot depends on your model.  But, sometimes you are able to change the orientation on the print bed to gain better detail when printed.  Some model however force their placement in order to be printed.  I did a HO scaled file cabinet that I was able to get a better print by placing the side on the print bed instead placing the back down.

If you print everything at a 0.2mm layer height for example, you are severely limiting the detail your printer can reproduce.  When I want fine details, I reduce my layer height and slow down the print speed giving the printer every chance at a good print.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #224 on: December 27, 2024, 03:44:31 am »
I'd rather not deviate towards slicing software issues as the one I use (Slic3r) is probably not very popular and keep it on topic of FreeCAD since I'm trying to learn more than just padding a square.

Maybe soon I'll learn how to pad a rectangle, but that's next semester. :)

Anyway, attached is four screen shots. I created a square, placed two circles in it, padded it, and added fillets. The fillets on the holes are on both sides and both all four fillets are 0.04". The short sides have a fillet of 0.03", and the longer sides have a fillet of 0.02" (I couldn't go any larger without it giving an error).

As the picture shows, I did a CTRL-A and exported it. In the slicing software in the platter preview, it doesn't show the fillets. I changed the layer heights to 0.1mm and it still doesn't show; but shows in the 'preview' window (although it doesn't seem to show the edges nor does it show the edges on the 'layers' preview).

I may be wrong, but believe in the platter view the layer heights and settings don't impact that view, only the preview and layer windows.

In any case, this is where I begin questioning: did I export it wrong in FreeCAD, or is the slicing software showing an error? Then I print it at the default of 0.3mm, but can't tell if fillets are present; although maybe in this case the fillets on the holes would be obvious since they are so large.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #225 on: December 27, 2024, 04:02:43 am »
I'll make it real simple:  NEVER USE CTRL-A in FreeCAD!

This is version 0.16?

Either select 'Block' or 'Fillet007' to export.
Assuming 'Block' is a 0.21 body. 
If 0.16, you probably can't select 'Block' and your only choice is 'Fillet007'.


Select ONLY ONE item in the tree to be exported.
« Last Edit: December 27, 2024, 04:12:45 am by MarkF »
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #226 on: December 27, 2024, 09:44:32 am »
The FreeCAD tree is a recipe for Chocolate Chip Cookies.

When you want a cookie:

  YOU DO NOT
    - Add flour, sugar, eggs, chips, etc. to a bowl
    - Mix the dough
    - Drop on a cooking sheet
    - Bake for 10 minutes
    - Let cool
    - Eat

  YOU JUST
    - Eat the cookie


If you make everything you selected for export visible, you will see what you have in the slicer.

Also, you can fillet more than one edge at a time.  For edges with the same fillet size, you can add additional edges by CTRL-Click more edges before doing the fillet.  You can also add/remove edges from the fillet tab.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #227 on: December 27, 2024, 03:08:44 pm »
Quote
  YOU DO NOT
    - Add flour, sugar, eggs, chips, etc. to a bowl
    - Mix the dough
    - Drop on a cooking sheet
    - Bake for 10 minutes
    - Let cool
    - Eat

The analogy is not only a good explanation, but hilarious. I get the tree structure better now, but, to be a bit sarcastic. If I add a sketch (sketch1) to a face, and then 'pad' it or make it a 'pocket', the tree becomes <pocket> and underneath it <sketch1>. i.e. 'sketch1' is the last in the tree.

This is similar to adding "clean the plate" which now becomes the last item on the list under "eat", so (normally) I would have picked "clean the plate" thinking "clean the plate" wouldn't be included if I selected "eat the cookie". Hence, I'd lose "sketch1" because I selected the "pocket" above it.

Yes, I'm being a bit sarcastic, but I'm also pointing out that it's not as simple as picking the last in the list.

Now that I get the tree structure better, I should have less issues exporting.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #228 on: December 27, 2024, 04:50:53 pm »
I must point out that a sketch is not a 3D-object.

It's just a two dimensional drawing.
It has no height.
It has no interior.
It's not solid.
It's not something you can print.

No. It's not as simple as picking the last item.
You have the option of picking anything.
To over simplify, my point is you ONLY pick one item.
« Last Edit: December 27, 2024, 04:54:48 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #229 on: December 31, 2024, 12:18:41 am »
I watched the video posted in Reply #216 and thought it was excellent (I need to watch it again), but helped explain adding shapes to non-planer shapes - this was the video regarding adding shapes to non-planer surfaces and involved making a bracket (?).

Regarding that video and a discussion from prior. I asked whether "touching" a shape to another shape would result in a weak bond when printing and believe the answer was overlap is fine. My question revolved around a box and a cylindrical shape. I asked whether "touching" the cylindrical shape to one of the sides of the box would result in a weak bond.

In that video, he created half the bracket (?) and then mirrored it to make it a full bracket. Does that create two "halves" (i.e. a microscopic gap) that will result in a weak bond when printed or does the software (FreeCAD in this case) know enough to make it one uniformed shape?

Another question I had is piggy backing off my last one. In the attached shape (I tried to come up with a comical name since some of you enjoy my file naming), let's call it a purse since it resembles that, how do I edit the non-planer part to say curve the strap a little to avoid the edges cutting into the hand carrying it?

Not curve the entire strap into a U because I think that may be simpler since it's a uniform shape, but say I wanted to curl the edges slightly and leave the rest of the strap flat without cheating by making a fillet on the faces.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #230 on: December 31, 2024, 01:00:13 am »
In that video, he created half the bracket (?) and then mirrored it to make it a full bracket. Does that create two "halves" (i.e. a microscopic gap) that will result in a weak bond when printed or does the software (FreeCAD in this case) know enough to make it one uniformed shape?

Since the bracket has symmetry around the center, he saved time by only drawing half and mirroring it.  The results would be the same if he had drawn the whole bracket without the mirror.

After the mirror, there won't be any microscopic gap.  The bracket will be one complete solid.  The strength will depend on the cross-section where the mirror occurred.  The same with the two shapes in the example you created.  Once you have them so they form one object, the strength comes from the cross-section where they meet.  As you build your shape, it becomes a solid and the strength comes from the cross-section at any point and the characteristics of the material you print with.


Quote
Another question I had is piggy backing off my last one. In the attached shape (I tried to come up with a comical name since some of you enjoy my file naming), let's call it a purse since it resembles that, how do I edit the non-planer part to say curve the strap a little to avoid the edges cutting into the hand carrying it?

Not curve the entire strap into a U because I think that may be simpler since it's a uniform shape, but say I wanted to curl the edges slightly and leave the rest of the strap flat without cheating by making a fillet on the faces.

Here you need to think outside the box a little.  No one says the handle has to be a single circle.  In the sketch, build the upper half as a semicircle.  Then extend the ends with an arc to connect to the purse.  The extensions can be of a different diameter than the semicircle to get the shape you want.  If you want to go overboard, you can use splines or pipes to create a custom shape.

"So, how long have you been carrying a purse?"
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #231 on: December 31, 2024, 01:44:14 am »
Quote
The strength will depend on the cross-section where the mirror occurred.

I must have misunderstood initially.

So if I create two cubes (let's say a pair of dice) and "touch" them, it will print as one solid (the same as if I created one large square/rectangle) rather than a microscope gap between the two; and it would be a strong bond since the cross sectional area is quite large (assuming a standard size pair of dice and the entire sides are touching).

Quote
"So, how long have you been carrying a purse?"

As soon as I send this 3D design to the printer and it prints. :)
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #232 on: December 31, 2024, 04:42:23 pm »
I created two blocks and "touched" them. I created the first block, added a second to the face, created geometry lines, and used the geometry to start the side of the second block.

Looking at the slicing software, it appears it's one "complete" solid part, and believe I answered my own question.

I assume if I put a microscopic space between the two blocks of something so small such as 0.001", then it would technically be two separate blocks that could split apart; assuming a perfect world and perfect printer.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #233 on: December 31, 2024, 05:48:30 pm »
I can't figure out where you're going with all of this.

You seem to be banging your head why you get the 'multiple solids not currently supported' in FreeCAD.  Most of the time this is due to limitation in the precision of floating point numbers.  Sometimes a 5 in a floating point number is 4.999999999999.  You will notice in the last tutorial he pointed out where there was a small gap due to the angles involved and the solution is to overlap the pad a small amount.  It doesn't hurt to embed the pad into the other solid to fill in any gaps.  This shouldn't be a problem if you are able to map the sketch onto a face.

In your dice example, look at how the layers are printed.  If the nozzle moves in two loops for each layer, it will not be as strong as if the nozzle moved in one big rectangle.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #234 on: January 01, 2025, 04:44:11 pm »
The direction I was going was just understanding whether (using the video as an example) mirroring half the bracket results in a weak point in the middle because it would print them separately or whether it ends up being one complete solid uniform piece.

To experiment, I tried a similar approach by just touching two cubes together (using geometry) and the slicing software showed that it was truly printing it as one complete uniform piece.

My statement that if I added a microscopic gap by placing the second cube a fraction of an inch away, then technically it would be printed as two separate pieces.

This is all I was stating. I wasn't doubting the feedback/advice from anyone, and sometimes my messages are rhetorical or stating that I took the time to "experiment" in order to get an understanding of what was discussed.
 

Offline Old Printer

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Re: Resize a STL File For Me
« Reply #235 on: January 03, 2025, 12:24:14 am »
Bostonman, you can put this to bed by doing a couple test prints. Put two blocks together as you have described then watch them print. My experience is limited to a Fusion, Bambu P1S and Bambu Lab slicer, and I had this same concern. My tests printed as one. The nozzle went past the seam as if it was not there and the finish in the join area showed nothing.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #236 on: January 03, 2025, 03:36:54 pm »
Yes, you're correct, but it was answered by others already and seeing the slicing software showing it as a whole helped.

Hopefully nobody took my questions as doubting the answers or any other negative fashion. Sometimes I ask obscure questions that are interpreted as a waste or explain how I proved the answer to visually see the results, but it confuses people because they already provided an answer.

It's because I'm the type that if I'm driving somewhere, come to a fork in the road, knowing I need to bare right, I may bare left just to see what is there.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #237 on: January 17, 2025, 08:55:53 pm »
Does a way exist to pad at an angle, or does fancy geometry need to be done?

I’d like to attempt making some missing feet for a table saw stand - see attached.

I can create most of it except the angle.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #238 on: January 17, 2025, 09:16:31 pm »
I don't understand what you want to pad?

Can you describe it more or draw over your photo?
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #239 on: January 17, 2025, 09:48:58 pm »
Oh...  The photo is the actual foot you want to duplicate.

Just draw the triangle on the bottom and pad it.
Then draw the right angle and pad it.
Both sketches on the XY plane.

You can pocket out the interior or just use the slicer fill pattern to do it.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #240 on: January 17, 2025, 09:50:52 pm »
I made the mistake of thinking everyone could read my mind. :)

I started by making the triangled flat part that sits in the floor and padded it, maybe 3/16”.

After I created another sketch on top making the V shape, padded it (maybe 3/4”), and then added a groove for the slot.

The issue is trying to make that V with the groove an angle.

Maybe the steps I’m taking are wrong, but that’s the route I took (although it was a rough drawing without correct dimensions).
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #241 on: January 17, 2025, 09:54:57 pm »
So the V or right angle tall part is not vertical but sits at an angle to the floor?

Does it look like this?

  2484491-0
« Last Edit: January 17, 2025, 10:19:24 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #242 on: January 17, 2025, 10:59:43 pm »
Not sure if this picture helps.

Basically what you posted seems to be the same as the feet I’m looking to duplicate.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #243 on: January 17, 2025, 11:14:45 pm »
I still can't tell.

Basically the table saw legs are a piece of angle iron?
They go inside of the plastic foot in the groove shown?
Are the legs angled from the floor or are they perpendicular to the floor?
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #244 on: January 17, 2025, 11:23:48 pm »
I can draw it with a 'pipe' but that may still be beyond you yet.
Take a look.  It's NOT fully constrained and you would need to adjust ALL the dimensions.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #245 on: January 18, 2025, 01:50:00 am »
I couldn’t get a good angle.

Yes, the four legs are angled both on the X and Y plane. So they are (maybe) 25 degrees in both directions; and it’s angle iron.

The table saw was being discarded years ago on CL. Now the legs with missing plastic feet tend to make 90 degree rust marks on the concrete and thought printing feet would be a nice project.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #246 on: January 18, 2025, 02:55:11 am »
The angle in my model is currently at 10 deg.
You can change it in the 'Sketch-profile' under the 'AdditivePipe'.

I measured my Delta Contractors table saw and it was 5 deg.


Actually there are 3 sketches that need to be modified to change the skew angle to the floor:
  the 'Sketch-profile', 'Pocket', and 'Pocket001'.
« Last Edit: January 18, 2025, 03:33:40 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #247 on: January 18, 2025, 09:02:52 pm »
You're spoiling me by doing this stuff for me. :)

That foot looks identical to the original and looks great, however, I haven't' applied any dimensions yet to tweak it. Your honesty about a "pipe" being beyond me is appreciated. It's obvious I don't try to lie about my lack of FreeCAD skills but I'm trying to learn. Unfortunately I lack a bit of creativity, so I get stuck in a 2D world with simple padding to make it 3D.

For reference, I took measurements of my table. It's 23" tall. The front (can we call it a trapezoid?) is 18.25" across on the top and 26" across on the bottom - this would be looking at it from the front. The "trapezoid" on the side (now I'm walking to the right side of it and looking at the side view) is 20.5" on the top and 28.25" on the bottom - obviously still 23" tall.

If I did my trig correctly, that's (rounding off) 20 degrees which isn't far from my estimate of 25.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #248 on: January 18, 2025, 11:37:22 pm »
I get something different.

Front:
  26 - 18.25 = 7.75  wider at bottom than top
  7.75 / 2 = 3.875  wider on each leg
  tan-1(3.875 / 23) = 9.5 deg,  angle = arctan( opposite / adjacent)

Side:
  28.25 - 20.5 = 7.75
  7.75 / 2 = 3.875
  tan-1(3.875 / 23) = 9.5 deg

An angle of 10 deg would seem correct.

2485307-0
« Last Edit: January 18, 2025, 11:57:49 pm by MarkF »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #249 on: January 19, 2025, 12:32:35 am »
Oh….. I didn’t divide by 2. I took the inv tan of the height and delta of the width.

Thanks for the correction.

My angle was correct; if I wanted one leg vertical and the other angled. :)
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #250 on: January 21, 2025, 05:43:59 pm »
I just finished my first model where I imported a photo to use as a reference.  I wanted to try using this capability for a while but didn't have a need.  It was remarkably easy and my first print was spot on size.

I wanted to print road crossing ramps for the track on my model railroad layout.  To start, I laid a piece of paper over the rails and trace them.  From there, I took a photo with a ruler in the view for scaling in FreeCAD.  (You need to take the photo as perpendicular to the object as possible.)  After importing the photo into FreeCAD, you need to scale it for use.  Here, I right clicked on the photo in the tree and selected the ends of the ruler and gave FreeCAD the length.  After scaling, it was just a matter of drawing the shape.

A nice bit of kit for the toolbox.

2486767-0


 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #251 on: January 22, 2025, 02:39:43 am »
Quote
It was remarkably easy and my first print was spot on size.

You're just showing off now. :)

Not sure if you have a scanner, but could you have used a scanner so the picture came out more perpendicular (ignoring that you got the picture spot on)? I've scanned things before by leaving the cover open and covering it with something to avoid external light getting in the scan.

Have you ever considered a 3D scanner? I've done searches for them and found many, but I don't have much of a need for one except bragging rights.

Also, I'm sure you know this, but if you need multi color prints, they can always be painted.

I haven't tinkered with the dimensions of the bench foot you made but plan to. Currently the cold and recent snow is limiting many hobbies. Although very simple and basic compared to what you (and others) created, I pieced together a plate for my Arbor Press.

My press is small, got it off CL for $35 a few years ago and used it several months ago to replace bearings in a drill press. The issue is that it didn't come with a plate or anything else. Long story short, I printed a cone shape to assist with removing some of the bearings and remained shocked how tough the print was. Not sure how strong this plate will be (I'm planning to print at 80% or maybe more infill), but it may be enough for any future projects. The slot and hole sizes are somewhat random as I didn't find any standards online. The slot on the press is about 1-1/8", so I made one slot that width.
 

Online CatalinaWOW

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Re: Resize a STL File For Me
« Reply #252 on: January 22, 2025, 04:33:33 am »
A flatbed scanner works very well for collecting geometry.  And I usually don't have to put a shroud over the object to get good enough contrast.  You do run into problems with anything that isn't flat against the scanner surface.  The problems are fairly obvious in the image and you can usually apply some Kentucky windage to work it out.  But it is fabulous for making gaskets and the like.  The newest versions of FreeCAD have improved image import dramatically.  It is really easy now.

If you have any serious work to do on your press I suspect your 3D printed parts won't be up to the task.  I have tried a couple of times to do things like this.  An example a two inch thick shim to allow use of a tool from a 6" swing atlas lathe on my 10" swing lathe.  It looked and felt seriously strong, but the first time I attempted a real cut it failed completely.

I was gifted one of the moderate cost 3D point scanners a couple of years ago.  It is pretty impressive for non-precision work.  Scanning a persons face allows making a print that looks like the person.  But it is fiddly to use, the software is temperamental, the workflow isn't totally obvious and the accuracy isn't much beyond the James Watt fit specification for his steam engines (can't put a five farthing piece between the piston and cylinder wall).  It is possible that they have improved in the last couple of years, but I would recommend saving your money.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #253 on: January 22, 2025, 01:42:58 pm »
I do have a flatbed scanner, but you have to be able to get the object onto it. 
A 7x10 ft railroad doesn't fit very well.   :-DD
I don't think I would find much use for a 3D scanner.  I just don't do that kind of work.

Using a photo has a niche place in CAD modelling. 
This is the only case I have been able to use this capability.
It was a savior in this unique case to get the complex geometry into FreeCAD.

As for strength, I use mostly PLA and found it's not as strong as I would think.
I doubt a base plate for your press would survive your first press.
Even carbon fiber filament would be hard put for tough tasks (if you could even print it).
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #254 on: January 24, 2025, 02:06:37 am »
MarkF, you never mentioned how you created the angle for the table saw foot. You mentioned it being beyond my level, but I'm always up for learning existing methods so maybe I can apply them in the future.

Maybe I won't remember how to do it, but at least I know what exists so I can try searching for it. Things are much harder when you don't know what to look for or terminology on what to look for.

The angle iron is only 1-3/4" of an each on each side, and approximately 0.07" thick (slightly over 1/16th" of an inch thick). It's not a very big foot, but the angle was the only part preventing me from creating one for some time.

Not sure if I'll print it using TPU or PLA. The TPU is more forgiving with sizing since it stretches and it's durable, but might grab the floor too much.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #255 on: January 24, 2025, 04:27:10 am »
If you expand the AdditivePipe in the tree, you will see two sketches.  One is the profile of the shape I want to create and the second is the path to sweep the profile over.  It's like doing a Pad except that it follows a path.  You will also note the two Pockets following.  Their sketches also have the angle needed to trim the ends of the Pipe to bend them in at the bottom of the foot.

The pink parallelogram is the profile and the yellow line is the path.

2488095-0

Another view with one of the Pocket sketches (green) to trim the ends:

2488109-1

You would change the path to match the width of the angle iron plus twice the thickness of the foot.

You would change the top of the parallelogram for the thickness of the angle iron plus twice the thickness of the foot.

I would print with PLA.
« Last Edit: January 24, 2025, 04:54:02 am by MarkF »
 

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Re: Resize a STL File For Me
« Reply #256 on: January 24, 2025, 05:00:57 am »
Another option would be to add a solid plate to the bottom of the foot, print it in TPU to allow it to have a tight fit on the leg, and then bond a material with the properties you want onto the bottom.  Rubber, nylon, felt or whatever.  Or go the hardware store, pick a foot that has the floor interface that you want, and then make the appropriate shape so this foot sleeve mates to the foot purchased in the store.  An adapter so to speak.  One very appealing option is to make the adapter mate to one of the screw thread adjustable feet that you can buy.  Then you can level your saw even if the floor isn't level or flat.

The real beauty of 3D printing is that there are very few constraints on the shape.  The sky is the limit.
« Last Edit: January 24, 2025, 05:03:09 am by CatalinaWOW »
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #257 on: January 24, 2025, 03:59:27 pm »
Quote
The real beauty of 3D printing is that there are very few constraints on the shape.  The sky is the limit.

I fully agree and why I think this stuff is so cool. Even just spinning a shape on the screen looks cool.

Unfortunately, as mentioned, my brain lacks some creative ability (I've always been more of the person who disassembled stuff, figured out how it worked, repaired it, etc...) and I also tend to draw stuff in 2D models.

When I went for my BS, I took a drafting course and was taught to draw showing the front, side, and top view (I forget the term for this) and that's how I show most drawings when I'm explaining something to someone. Others whip out nice 3D hand drawings when they explain stuff.

Having said this, I think these are reasons I struggle with creating 3D shapes along with stuck in the mental mode of a simple 2D model that gets padded (or a revolution for a shape).

The table saw itself (a freebie off CL years ago) didn't have a fence. Recently I thought of using that aluminum stuff that can be screwed together (I don't know the name of it - it has lines in it along with holes - but have some long pieces). They are straight which may be a perfect fence. I came up with the idea to model the handle part along with the hook and maybe threaded rod to reach the other end of the table.

I have the image in my head based off Internet pictures, but struggle to come up with an actual working design. This all relates to what I stated above regarding lack of creative ability.

 

Online MarkF

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Re: Resize a STL File For Me
« Reply #258 on: January 24, 2025, 04:39:12 pm »
DIY table saw fence:

 
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #259 on: January 26, 2025, 02:56:27 pm »
Thanks for the links. I may have seen that video before when i searched for DIY fences.

People come up with some elaborate, and simple ways of making stuff. Some though make it look easier than it is.
 

Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #260 on: February 05, 2025, 02:36:12 am »
I'm back to struggling with exporting to a STL.

As told to me, the 'tree' on the left is a cake recipe and I select the last step to export. For whatever reason the holes are not exporting.

In some cases I get half the drawing or part of the drawing.

Although many ways exist to do 3D drawings, I drew the top half and mirrored it. After I created a standoffs and mirrored those (although I think a way exists to do an array).

If anyone digs into the drawing and/or steps, I think they'll have a good laugh because I probably took the hard road including many construction lines that probably didn't need to be used.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #261 on: February 05, 2025, 04:36:51 am »
Sorry.  But, there are so many errors that I don't even know where to start.
You have a serious phobia with mirrors and you are not consistent with them.  Take the corner standoffs to start.  You mirror them I suppose so their all the same.  However, one is not like the other three.

My suggestion is the start over with a new model and place the center of the coordinate system in the center of the model.  Then, model only one quadrant with just the solid base, with one corner section and one standoff. 
Then mirror right to left.  Then mirror those top to bottom.  Afterward pocket all the holes.  And finally, do the fillets.

You MUST systematically divide the model into pieces and build it up.  I can't isolate all the pieces and neither can FreeCAD.  PAD002 should look like a mirror of PAD003 but some how it has the lower half attached.

You can't export the model because the geometry is broken in places.
 
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Online rteodor

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Re: Resize a STL File For Me
« Reply #262 on: February 05, 2025, 04:41:46 am »
I would do it a bit differently using only 'Part Design' and 'Spreadsheet' workbenches. I was a bit lazy: all dimensions would have to go into the spreadsheet...
By exploiting symmetry as much as possible starting from the sketch, there is no need for any mirroring.

To be noted in the first sketch, I may have simplified it and use arches for the sides. That I think was your intention but I might be wrong.

2495307-0
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #263 on: February 05, 2025, 05:37:04 am »
I would do it a bit differently using only 'Part Design' and 'Spreadsheet' workbenches. I was a bit lazy: all dimensions would have to go into the spreadsheet...
By exploiting symmetry as much as possible starting from the sketch, there is no need for any mirroring.

To be noted in the first sketch, I may have simplified it and use arches for the sides. That I think was your intention but I might be wrong.


That's probably the best way.  He is not really saving anything in the long run from doing the mirroring.  In the end trying to put the holes and fillets in afterward is a lot more difficult and involved then just drawing each piece outright.  In fact it is down right a struggle to do.  A bit of déjà vu for me.  You end up with something that is NOT part of a body and you can not operate upon it.  There are some tricks that I keep forgetting to make it work.
 

Online MarkF

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Re: Resize a STL File For Me
« Reply #264 on: February 05, 2025, 07:35:51 am »
@Bostonman

Here is the Display Box cleaned up.

I deleted everything except the three basic sketches:  the bottom, the top sides, and one standoff.
Then I mirrored and positioned the sketches into their correct location.  Padding each as I went.
After which, I pocketed the three holes.  Followed by the fillets.

Just mirroring and padding the sketches in a more logical order allowed me to export the last item in the tree (i.e. the fillet).  I could have just clicked on 'Body' for the export.

You really need to plan a more systematic approach as you build-up the model.
I also tweaked a few of the sketches trying to add constraints and keep the dimensions the same as you had.
« Last Edit: February 05, 2025, 07:38:27 am by MarkF »
 

Online rteodor

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Re: Resize a STL File For Me
« Reply #265 on: February 05, 2025, 12:38:49 pm »
I would do it a bit differently using only 'Part Design' and 'Spreadsheet' workbenches. I was a bit lazy: all dimensions would have to go into the spreadsheet...
By exploiting symmetry as much as possible starting from the sketch, ther