Replacement Knobs, Feet and Fittings for Test Equipment

[Jay_Diddy_B]

Hi,
I purchased a TDK Lambda GENH series power supply from eBay. One of the two knobs was missing. They are simply pushed on and there is no real retention mechanism.

I used Fusion 360 to create a model of replacement. I printed the replacement in white PLA.
I reduced the number of bumps on the outside to get a better print.




Replacement




Edit: Here is a picture showing an original and the 3D printed part:




The same knob is used on Lambda GEN  and ZUP series power supplies.

I have attached the files.

Regards,
Jay_Diddy_B
 lambda knob.zip (408.63 kB - downloaded 253 times.)

[dl6lr]

I got a Rohde&Schwarz BOL (rebranded National VP-5512A) with a broken rear foot. So I designed a replacement to be printed.

This is somehow simplified to the original molded one. The scad file is ugly hacked together without parameters.

It can be printed without supports by laying it flat on the bed on the slanted side.
Just add an adhesive rubber bumper if you want.

The second one tries to imitate the original corrugated design. I haven't printed it yet.

Can be found at Thingiverse: https://www.thingiverse.com/thing:4966337

[Paceguy]

Does anyone know where I can find a replacement frequency knob for my HP 339A Distortion Measurement Set? Can some one here make one for me? I temporarily installed an old hp knob but have to count the turns since it does not have a numbered 1-10 skirt. Thanks in advance!

[CatalinaWOW]

Here is a fairly often broken part that isn't available anymore.  The cooling fan impeller for a Tektronix 2465 Oscilloscope and its matching collet.

The fan can be printed bottom down without support.  The collet should be printed thin side down with a raft for adhesion.  Density isn't too important for the impeller, but the collet should be printed at high density.

The collet needs a stud in the end, with matching nut.  You can use SAE or Metric as is your preference.  Printing the collet at high density allows for drilling and tapping to match your choice, though it should be possible to melt it in with care to get it straight.

The original part uses a metal reinforcing ring at the top of the shaft.  That ring could be salvaged from a broken part, but many won't have that part or the ability to fabricate the ring so this design settles for adding more plastic in this area.  Would greatly complicate the mold if that were how this part was going to be made, but not an issue for 3D printing.   This will probably fail after a decade or two of use, but that is just time to print another.

The picture shows that I don't go for perfect finish on my functional parts, but it works fine and is completely hidden under the back cover of the scope.

Those who can't or don't want to print their own can message me and we'll work something out.

SEE LATER POST FOR CORRECTED (IMPROVED) MODEL

[Kean]

I don't have a 2465 but I'm printing one of these anyway because it is so cool 

[TERRA Operative]

If you were to put a 45 degree chamfer under that overhang where the metal ring would sit, it will help prevent dags hanging down as seen in the photo.

[CatalinaWOW]

If you were to put a 45 degree chamfer under that overhang where the metal ring would sit, it will help prevent dags hanging down as seen in the photo.

I have better luck with fillets than the chamfer and this was intended to have a fillet at that joint.  Went back and found that the fillet was missing.   Attached are the corrected models.

Thank you for taking the time to look closely.  I hadn't noticed the error before, because for my purposes it was "gootenuf".

[Johnny10]

 

[Matsh]

If you need knobs printed I can help with the Print-out on a Form 2 printer.

[dl6lr]

-hp- 1744A storage scope (and many others):

Mine lost a pushbutton, especially the one for AUTO-STORE in the upper left corner. So I removed one of the others, took the dimensions and made a somehow similar design.
Printed in PLA with 0.1mm layers and slightly sanded, it is a press-fit to the switch. With a SLA printer you may want to recalculate with more facets to have a smoother finish (beware, will take ages to calculate).

https://www.thingiverse.com/thing:5141182 (Once again it is not showing any images yet...)

OpenSCAD design file is included in the ZIP with the STL...

[Le_Bassiste]

tautech suggested to post this here: Feet for FLUKE 540B, and FLUKE343A, FLUKE 5450A and alike.
https://www.eevblog.com/forum/repair/chassis-feet-for-fluke-540b-and-fluke-343a/

[dl6lr]

Vintage hp test equipment feet (i.e. 5245L, 5345A etc.)

Those feet have a spring loaded pushbutton to install/release the feet. I redesigned a functional but simplified foot that can be installed from the inside only using a M2.5 8mm socket head cap screw (sorry, no idea what kind of imperial screw can be used). A button head can be used too.
I already have an idea how a simple spring loaded push button could be made with standard parts, but springs that would fit are hard to find.

https://www.thingiverse.com/thing:5142216

STL and OpenSCAD file included in ZIP.

[CatalinaWOW]

Rainy days made for several models.

First for Tektronix 465 Oscilloscope (and probably several others in the series.)
  a.  Bezel for the CRT
  b.  Trigger level knob
  c.  Trigger slope knob
  d.  Horizontal position
  e.  Fine horizontal position

I didn't have the original aluminum collars for these so designed them around standard set screw collars from McMaster-Carr.  Part number 6432K71 for the trigger slope knob and the horizontal fine position knob and part number 6432K17 for the other two knobs.  Unfortunately the inner diameter is not correct on these collars and must be drilled out to match.  I also had to chase the set screw threads after drilling, YMMV.  I used Gorilla Gel CA to mount the collars in the knobs, but there are many good adhesive choices.

Also learned that the SC-504 knob core mentioned earlier in the thread works in the Tektronix 2230 and probably several others in that series.  Included the stl here.  There is another thread on the forum describing how to make the transparent skirt that has the gain legends.

Enjoy

By the way these knobs were generated for the 475 shown.  But I didn't have originals so they were patterned after 465 knobs that I did have.

[MarkF]

Rigol DS1000Z replacement feet:

The original feet have little detents to keep them open or closed and I believe the stress of these detents caused the feet to break.  My replacement feet are smooth and don't have the detents.  Because of this, I scraped off the small ridge on the case under each foot.

I printed them with a fine layer height and 50% infill.


Moved from 3D Printing topic

[xrunner]

Replacement range button for Boonton Model 42A and similar models.

These can be painted with glossy acrylic model paint if you wish, such as Tamiya X-1

https://www.tamiyausa.com/shop/acrylic-paint-mini-10ml/acrylic-mini-x-1-black/

Use a toothpick to place the dot using white paint, such as Tamiya XF-2

I'm posting some addendums, the first is showing what some final finishing can do for your 3D printed parts (mainly the parts that will show). I finished the button by sanding and priming (3 times). Then painting with Tamiya X-1 gloss black. I made the dot with Tamiya XF-2 flat white. The 3D finished button is on the left and the original right. It's nearly impossible to tell which is which once installed and the front bezel in place.

So just some finishing to your part, if it's one that needs to be "museum quality" can make a huge difference.

[masterx81]

Anyone know a place where find this safety banana plugs?
Thanks!

[BmaxTom]

Housing for Leo Bodnar's fast risetime pulse generator --> https://www.eevblog.com/forum/projects/yet-another-fast-edge-pulse-generator/

Printed it with a layer height of 0.1mm and infill grid pattern with a density of 33%. I attached the cover with a little bit of super glue.

[BmaxTom]

Siglent housing spacer for e.g. SDM3065X and SDG2042X.

Printed it with a layer height of 0.2mm and infill gyroid pattern with a density of 25%.

[Peter_O]

Usually I mount 38mm 'adam hall' rubber feet with a printed plastic nut. In case it falls off inside the device, it will cause no problems.

My new old HP6653A power supply does not have a bottom cover plate, but the chassis itself is the bottom. So it would be a lot of dismounting to place a nut inside.



So I'm back to HP's hook and lock system.
The avaiable print models copy the plastic spring locking of the original.
As prints often do not reach that level of plastics quality and precision I was not conviced and scribbled another solution:



The locking is done by a locking plate with konical cotters and is fastened by a screw.
On top is a furrow to allow pliers to grab and pull out the locking plate.







On top of that I mounted the usual rubber feet to save table tops or other device covers.



The front alignment key part of the HP feet is not that important for me. I place to 4mm threaded holes in the front of the feet, but obviously this was not planned to the end. 

Anyhow, for me, it does the job for now.

You can find the STLs without the front holes in the zip file attached as well as on thingiverse:
https://www.thingiverse.com/thing:5352112.

[andrejr]

If someone needs a replacement button for a Gould Delta 9500A, I've 'drawn' one in OpenSCAD, printed it and it works fine. The STL, scad (in the 7z) and image files are attached: in the image, the "Print" button is printed, the others are original.

This same kind of button is also used on all Gould Classic series scopes, and a bunch of Nicolet scopes, such as the Nicolet Integra series.

[Peter_O]

A printed button for the "print" function. Nice.

[mnementh]

      

https://www.amazon.com/dp/B09SP54HNW/

Just a quick heads-up; I found these on slAmazon while hunting stick-on feet for a particular project. They look to me like a good generic substitute for the OEM feet on many different models of TE. At $6/doz, pretty reasonable too.

Cheers!

mnem
 

[Monkeh]

Rigol DS1000Z replacement feet:

The original feet have little detents to keep them open or closed and I believe the stress of these detents caused the feet to break.  My replacement feet are smooth and don't have the detents.  Because of this, I scraped off the small ridge on the case under each foot.

I printed them with a fine layer height and 50% infill.


Moved from 3D Printing topic

Thanks for those, I snapped a foot off the other day - terrible design. Now replaced both with the last few metres of some purple PETG. I left the ridge in place as it provides a nice bit of drag to keep the feet from flopping about.

[SoundTech-LG]

Still in-stock just ordered some!

[CatalinaWOW]

The attached zip file has a FreeCAD parametric model for knobs found on equipment from the late 1930's to the 1950's.  Also included are brief instructions on how to use it, and an stl file for a knob resembling those used on Muirhead decade boxes.  Unfortunately I couldn't make it fully automatic, so some fiddling is required, but it can generate a wide range of sizes and patterns.  Enjoy.