Author Topic: Resize a STL File For Me  (Read 48802 times)

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Offline bostonmanTopic starter

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Re: Resize a STL File For Me
« Reply #150 on: September 25, 2024, 03:52:48 pm »
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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.

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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.
 

Offline 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 »
 

Offline 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.
 

Offline 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.

 

Offline 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.
 

Offline 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 »
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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.
 

Offline 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?
 

Offline 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 »
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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.
 

Offline MarkF

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Re: Resize a STL File For Me
« Reply #165 on: October 29, 2024, 08:47:26 am »
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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?

 

Offline 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.
 

Offline 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.
 

Offline 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 »
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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.
 

Offline 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 »
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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. :)
 

Offline 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.
 


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