Replacement Knobs, Feet and Fittings for Test Equipment

[calin]

Here is my small button for Lecroy WavePro 7300A . SCAD model and STL attached.
Note: Updated the archive as somehow was corrupted

[dl6lr]

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%.

May I ask what design you have used to print the BNC caps? I assume you have printed them, being the same color as the spacer...

[BmaxTom]

BNC Dust Cap.

Printed it with a layer height=0.16mm, shells=3 and infill density=25%.

[BmaxTom]

Ethernet Dust Cap.

Printed it with a layer height=0.1mm, shells=2 and infill density=25%.

[dl6lr]

BNC Dust Cap.

Printed it with a layer height=0.16mm, shells=3 and infill density=25%.

Thank you. Just tested, they had too tight fit with my prints. I measured the STL indicates 9.8mm inner diameter, but my prints came with 9.55mm inner diameter, outer diameter was fine. Had to scale up a little.

[DavidKo]

I have created new power button for Advantest devices. I have measured the original button from TR6143 to replace my missing button on R7210.

The source CATPart and STL can be found on thingverse.

[CatalinaWOW]

In https://www.eevblog.com/forum/testgear/replacement-knobs-feet-and-fittings-for-test-equipment/msg2318376/#msg2318376 I posted a model for HP 5040-7201 feet.  I recently had need to print some and found that errors in the model existed that my prior slicer didn't catch and there were some dimensional problems which made trimming and fitting necessary.  The attached zip file contains the corrected stl file, the corrected model in FreeCAD format, and a crude model of the wire bail foot associated with the plastic part.  The bail is pretty easy to bend up from 0.125 inch steel wire, but if you don't have at least one existing foot it is helpful to have dimensions and angles.

My apologies for the poor item naming in the model and the crudeness of both.  This poor EE is still a rank newbie at solid modelling.

Also note that these feet are still available commercially.  Printing them is only necessary if you want other colors or have other reasons for printing.

[AVGresponding]

The main reason for printing your own is the satisfaction you get from not having to pay (since anyone printing them already has the printer and filament). Thank you for taking the time and effort to update your design.

[CatalinaWOW]

This isn't quite a perfect fit for this, but I found it useful when doing the stuff in this thread.

I needed a new front and rear bezel for one of my instruments.  The old one was fragmenting rapidly, already in a dozen or more pieces.  Unfortunately the bezel is larger than the build volume of my printer, so it needed to be printed in parts.  And it was desirable to have built in alignment and features for a strong bond joint between the parts.  The two models attached form this function and also give the basic idea for those who need to split even larger assemblies.

The basic procedure is to place the target part model within the volume of the right and left splitter.  Make a copy of the target model and then use your CAD program to do the AND or COMMON process between the original and the left splitter and the copy and the right splitter.  The two results can then be printed and then bonded together with the appropriate adhesive.

I am sure this idea is so obvious to some here that it isn't worth posting, but it took me a while to come up with a nice general solution and there may be others as slow as I am.

[minifloat]

For everyone who wants to make a Tektronix 1103 probe supply clone:
3D models attached for the shroud of the TekProbe interface.

'Made 'em for this https://www.eevblog.com/forum/testgear/tek-p5205-hv-differeantial-probe-teardown-btw-what-are-the-red-and-brown-wires/msg4610551/#msg4610551 "Hacktronix" device.

br, mf

[hpw]

After long FreeCad trial and understanding as in addition required 3D printing cycles too... I have it now 

but as 3D printing with matching colors is still an issue as it looks not available 

BTW: it is for LeCroy 6000, 7000, 8000 models..

Hp
 

[xrunner]

but as 3D printing with matching colors is still an issue as it looks not available 

Good work, but for color we sometimes need to use high quality model paint, such as Tamiya (flat or gloss), to get a closer color match. 

Tamiya Paint

[ZigmundRat]

Looks like a nice fit. Can you please share files here? Thx.

[KeBeNe]

Hi,

as I am restoring an R&S SMIQ, I needed the potentiometer knobs for the LCD.
I created them in Inventor 2021, step file is also included.
Printed with a resin 3D printer.

[RAQU_PL]

Front panel for Agilent PSU E3648A and for the rest of the line.

Minor inaccuracies may exist.

If anyone is interested i have .ipt file, but it is too large to upload here.

[dazz1]

Hi

As part of a mod to replace the factory original high flow high noise fan on a HP 54600 series oscilloscope, I made some clip-on front feet risers to provide more space, and more air flow for the very low noise, lower flow Noctua fan I fitted.
I designed and 3D printed two spacer feet that simply slide over the factory molded front feet and lock in place.  The feet lift the scope a few millimeters to increase the space for exhaust cooling air to escape.  The only exit for cooling air is a grill in the base of the enclosure. 

Others have done the Noctua fan mod without raising the oscilloscope, so the feet mod is definitely optional with questionable and unmeasured benefit.  I could have done a before and after measurement of fan current to detect a change in air flow, but I didn't.

As always, I try and make my mods look like they are factory made. The new feet are close to the factory colour so it is not obvious the feet are fitted.  No screws, no holes, no modifications to the enclosure and all completely reversible.  The feet just slide on and lock into place.    They will not slide off with just lateral force (ie. normal use).

I included a shallow relief in the foot for gluing on a piece of rubber roofing material.    The rubber will provide some extra grip and reduce noise transmission by at least a few femtodecibles.


Just in case someone wants to do the same mod, I have also attached the 3D file of the design.    I printed with PETG. 

On a scale from brilliant to useless, this mod definitely leans to the useless side, but I got to design and make something.  Fitting the Noctua fan was definitely a good thing to do.  The fan is barely audible.

[Ice-Tea]

Anyone know how to get a 3D model for one of these?

[CatalinaWOW]

I am sure you have tried a search of the internet for the .stl or .step or .iges file format using the Manufacturer and Model number of the instrument this came from.  This works if either the manufacturer has released their design files to the internet, or if someone else needed the part, modeled it and donated the result.  My personal success rate in these searches is low, but it works often enough to be worth the attempt.

You have several options if that fails.  Find a local engineering firm and contract them to make the model (expensive and slow).  Or find a nearby student or hobby person willing to to do it for free (maybe at a maker space or local electronics club meeting).  Or get micrometer and calipers and make detail measurements of the part and post it them here with a plea for someone to turn them into a model.  Identifying what this came from may help in getting interest in doing this.  Or purchase/rent/borrow one of the 3D scanners, generate a point cloud of the part and use associated software to turn it into a model.  I don't think this approach would be very successful on this part because of the small size and potentially the need to duplicate internal geometry on the base of the part.

Or you can get one of the free modeling programs, and learn to do it yourself.  Fusion 360, FreeCad, Blender and others are among the most popular programs.  Learning FreeCAD  and doing this on my first knob, an item not too dissimilar to your part only took a few days.  This approach is beneficial in implementing the corrective iterations that are almost always needed in this type of project.  It is almost impossible to get the measurements for some of the critical dimensions so a bit of cut and try is often needed.

[Ice-Tea]

Thanks. Yes, I've searched the net and Thingiverse. It would seem I've found a forumite willing to lend a hand ;-)

All my attempts to get into something like FreeCad have failed. At some point I realise I'll never "really" be good at it and I don't need another skill that I "kinda" can do ;-)

[CatalinaWOW]

Thanks. Yes, I've searched the net and Thingiverse. It would seem I've found a forumite willing to lend a hand ;-)

All my attempts to get into something like FreeCad have failed. At some point I realise I'll never "really" be good at it and I don't need another skill that I "kinda" can do ;-)

I would encourage you to give another try to FreeCad.  I won't pretend that I am doing modeling right. My sons, who both do mechanical modeling professionally sneer at my efforts, but doing simple things comes fairly easy.  And even "kinda" doing like I do has proved extremely useful.  Having a specific project aids me tremendously in learning, you may find it the same.  When I run into a block trying to accomplish something I look for an Online tutorial and it is usually cleared up quickly.

Basically your knob appears to be a truncated cone with a hollow square rod for attachment to whatever it is going on to.  Using the Parts Workbench these are canned shapes.

A big aid can be if you can figure out the manufacturer of the switch or pot this knob attaches to (or a similar product).  These 3D files are much more readily obtainable, and can be subtracted from a simple knob model to get the attachment right.

Why don't you post some key measurements of your knob (diameter at top and bottom) and measurements of the base.  I (or somebody more competent) might get motivated to do at least a rough model to get you started.

As another path, you might search this forum and eBay for the instrument that this knob comes from.  On eBay you might find a non-working one sold for parts that meets your budget, while on the forums you might find someone who has a parts donor.

Finally, if your need is only for functionality and you don't care about appearance you can take some scrap plastic and with a drill, some jewelers files and an exacto knife carve something that does the job.  I have done this on a couple of occasions. 

[CatalinaWOW]

Actually the attached file should give you a start.  It is a parameterized version of a knob similar to yours.  You can plug appropriate dimensions into it and get something pretty close.  This is a quick and dirty job, so no error checking or anything.  18 flutes is the max allowed value and it will let you foul up just about any dimension.

[CatalinaWOW]

The previous discussion reminded me of a knob file I posted elsewhere, which should also go here.  It allows you to generate knobs similar to those popular on radios and test equipment in the 1930 to 1950 time period.  Just adjust parameters on the spreadsheet page and it will give a wide variety of knobs.  The screen capture shows one example of what you can generate.  Somewhat better instructions are included in the zip file.

[syzygy]

I thought I'd contribute how I sourced replacement feet for several of our Tek TDS scopes a few years back, because the Tek P/N was difficult to find for less than $20:

[ I'm cheap ]

Original Parts, Tek P/N 348-1703-00 (broken & whole), and 'Replacements':

[KG7AMV]

A few days later, another one:
Rear foot for a Sencore Powerite II PR570 variable isolation transformer - will probably fit other equipment from Sencore as well, there are a few things in this form factor.
https://www.thingiverse.com/thing:3624712

Thank You, Printed Some Fit Great... https://www.stevenrhine.com/?p=132208

[KeBeNe]

Since I needed the rear device feet for a PSL-3 from Rohde Schwarz and only had one, I created a new one. (Inventor .ipt + stp files in the zip)
In case someone needs it.