Author Topic: Replacement Knobs, Feet and Fittings for Test Equipment  (Read 6817 times)

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Offline Bicurico

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #75 on: March 20, 2019, 09:08:09 am »
Hi,

Here is my contribution: feet for the HP/Agilent 8590 spectrum analyzer series.

A little background: this series uses rubber feet around the case (front and back). These rubber parts get really worn out with time and in my case, the two units I purchased came without any feet. I think that the previous owner either "forgot" to put them back on or, my suspicion, the devices where installed in some rack or whatever.

Using these devices without the feet is not reasonable, because the metal case around the device has a joint on the lower side. If you put the device flat on a table, it will wobble to the left and right due to this joint.

Also, without the back feet, you cannot place the device in vertical position, for example in case of storage with small footprint.

This means I really needed some feet.

Casually, I am working on a software project that requires to capture 3D points using a Microscribe arm (https://revware.net/products/microscribe-portable-cmm/).

Also, I finally managed to repair an old unit that was a dumpster case and which I luckily brought home with me. The problem was one of encoders was broken, as well as one of the axis counter IC.

Anyway, having a Microscribe and knowing how to use a CAD software, I started the reverse engineering process by digitizing the surface where the feet attach to.

I guided my design through pictures of the HP 8594E, in order to make the front feet look as close to the original as possible and reasonable.

The back feet, however, are considerably different. That is because I actually disliked the original HP design and, also, I had to have print material consumption in mind.

So I designed them a little different, but I think the result is actually pretty good.

I had the feet printed in our office, where we have Markforged printers. I used a Markforged Mark Two with their Onyx material (https://markforged.com/mark-two/). This material is not the toughest of the available materials, but it is still very robust. In fact, it is unbreakable with your bear hands and can compete with aluminium. The only draw-back is the color: this material is only available in black and it is not easy to paint (I tried on a different component).

So the feet on my device are black instead of white-ish.

The surface finishing and overall tolerance is miles away from cheap 100 Euro China-Clone-Printer. Especially if you spend a moment figuring out what is the most favorable position to print each part (I left that to my colleague who operates the printers).

Attached are pictures and an archive with the STL files. Please note that the front feet are made of two different models - you need to print 2 of each. This is obviously because they are mirrored (Up-Left and Down-Right <-> Up-Right and Down-Left). Obvious? Well, I got the first trial wrong and printed 4 of the same kind...

Good luck!

Regards,
Vitor
« Last Edit: March 20, 2019, 09:18:17 am by Bicurico »
 
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Offline Bicurico

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #76 on: March 20, 2019, 09:15:04 am »
Here is another part:

A button for the encoder on the Rohde&Schwarz CMU2000 and CRTU.

Note that you need a 3D printer cabable of printing walls with 1.3mm thickness! This is needed for the inner core. If you use a cheap printer, it would probably be better to reinforce the inner support structure.

Regards,
Vitor
 
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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #77 on: March 20, 2019, 11:13:53 am »
Hi,

Here is my contribution: feet for the HP/Agilent 8590 spectrum analyzer series.

A little background: this series uses rubber feet around the case (front and back). These rubber parts get really worn out with time and in my case, the two units I purchased came without any feet. I think that the previous owner either "forgot" to put them back on or, my suspicion, the devices where installed in some rack or whatever.

Using these devices without the feet is not reasonable, because the metal case around the device has a joint on the lower side. If you put the device flat on a table, it will wobble to the left and right due to this joint.

Also, without the back feet, you cannot place the device in vertical position, for example in case of storage with small footprint.

This means I really needed some feet.

Casually, I am working on a software project that requires to capture 3D points using a Microscribe arm (https://revware.net/products/microscribe-portable-cmm/).

Also, I finally managed to repair an old unit that was a dumpster case and which I luckily brought home with me. The problem was one of encoders was broken, as well as one of the axis counter IC.

Anyway, having a Microscribe and knowing how to use a CAD software, I started the reverse engineering process by digitizing the surface where the feet attach to.

I guided my design through pictures of the HP 8594E, in order to make the front feet look as close to the original as possible and reasonable.

The back feet, however, are considerably different. That is because I actually disliked the original HP design and, also, I had to have print material consumption in mind.

So I designed them a little different, but I think the result is actually pretty good.

I had the feet printed in our office, where we have Markforged printers. I used a Markforged Mark Two with their Onyx material (https://markforged.com/mark-two/). This material is not the toughest of the available materials, but it is still very robust. In fact, it is unbreakable with your bear hands and can compete with aluminium. The only draw-back is the color: this material is only available in black and it is not easy to paint (I tried on a different component).

So the feet on my device are black instead of white-ish.

The surface finishing and overall tolerance is miles away from cheap 100 Euro China-Clone-Printer. Especially if you spend a moment figuring out what is the most favorable position to print each part (I left that to my colleague who operates the printers).

Attached are pictures and an archive with the STL files. Please note that the front feet are made of two different models - you need to print 2 of each. This is obviously because they are mirrored (Up-Left and Down-Right <-> Up-Right and Down-Left). Obvious? Well, I got the first trial wrong and printed 4 of the same kind...

Good luck!

Regards,
Vitor

Thanks for the models added to the index post.  :) Interesting project with the Microscribe and very nice prints off the Markforge and Onyx Filament too :-+

I got a couple of rolls of PLA+ I have been going to try and see if they produce anything noticeably better unfortunately any of the branded fancy filaments tend to cost way to much by the time we get them in Australia.
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Offline TERRA Operative

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #78 on: March 22, 2019, 06:28:09 am »
regarding those rear feet, this photo of a HP 3581A I found may come in handy.
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Offline Bicurico

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #79 on: March 22, 2019, 08:05:53 am »
Hi,

While the feet of your device are completely different from the feet used on the HP 8590 series, they show one of the reasons I decided to redesign them.

Notice that the screws have to be extra long! I made the feet, so that a much shorter screw can be used. Also, the feet go around the edge, securing the case (which the original 8590 feet already did, too).

Regards,
Vitor

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #80 on: March 22, 2019, 10:08:30 am »
Hi,

While the feet of your device are completely different from the feet used on the HP 8590 series, they show one of the reasons I decided to redesign them.

Notice that the screws have to be extra long! I made the feet, so that a much shorter screw can be used. Also, the feet go around the edge, securing the case (which the original 8590 feet already did, too).

Regards,
Vitor

Those feet are in reference to an older model Hewlett Packard Scope I guessed/designed some feet for a few days ago (one page back) :)

regarding those rear feet, this photo of a HP 3581A I found may come in handy.

Interesting seems that model has a long bolt unlike Tautech's earlier one. The Square top seems close to what I guessed for Tautechs and the Zipped STL's have a short and a long bolt option so with luck it should suit the HP 3581A too. The only difference seems to be a taper on the leg.
« Last Edit: March 22, 2019, 02:52:38 pm by beanflying »
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Offline CatalinaWOW

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #81 on: March 22, 2019, 11:35:01 am »
Great thread.  This is a sticky candidate.
 

Offline TheDefpom

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #82 on: March 22, 2019, 03:37:06 pm »
Thanks for sharing some of my replacement part designs.

I have a couple more bits which I didn't see listed (I could have just missed them).

Lever for HP PCB daughter boards: https://www.thingiverse.com/thing:2909930
Valhalla 2703 (and 2705) Front Handle: https://www.thingiverse.com/thing:2910473

I make new items as I come across things I need to repair, so the list gets added to as the need arrises.
« Last Edit: March 22, 2019, 03:44:15 pm by TheDefpom »
 
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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #83 on: March 22, 2019, 03:41:50 pm »
Thanks for sharing some of my replacement part designs.

I have a few a couple more bits which I didn't see listed (I could have just missed them).

Lever for HP PCB daughter boards: https://www.thingiverse.com/thing:2909930
Valhalla 2703 (and 2705) Front Handle: https://www.thingiverse.com/thing:2910473

I make new items as I come across things I need to repair, so the list gets added to as the need arrises.

Thanks for jumping in.  :) I haven't gone over Thingiverse is a systematic search yet it's on the 'list'  :palm: I will add your couple of extras on the index.

BTW How is your 2703 going now? I scored a really nicely working one unlike your problem child.
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Offline TheDefpom

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #84 on: March 22, 2019, 03:47:30 pm »
BTW How is your 2703 going now? I scored a really nicely working one unlike your problem child.
It was OK the last time I used it, I need to do a calibration on it, haven't done that yet, but I picked up a Fluke 540B thermal transfer standard (which I also had to repair) so that I can calibrate it with my Fluke 341A DC calibrator (which I also repaired).

I will do a video on it eventually!

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #85 on: March 22, 2019, 03:59:52 pm »
It was OK the last time I used it, I need to do a calibration on it, haven't done that yet, but I picked up a Fluke 540B thermal transfer standard (which I also had to repair) so that I can calibrate it with my Fluke 341A DC calibrator (which I also repaired).

I will do a video on it eventually!

I know that rabbit hole well. Buy another bit to Calibrate the first bit :-DD I have both of my Agilent 6 1/2 digits on their way to Keysight for Calibration at present, when they get home the entire fleet gets a proper going over and Tweak against the pair :-/O
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Offline CatalinaWOW

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #86 on: March 23, 2019, 05:57:28 am »
Base part for vertical gain knob for SC 504 Oscilloscope

https://grabcad.com/library/vertical-gain-knob-for-tek-sc504-1

The files are too large to post here.

Printing this was a long exercise as the photo shows.  On the left was an attempt to mold the part.  No go with deep thin walls.  The key settings as I remember were Cura Fine print settings for base, with 92% density (supposedly optimum for strength), used PLA+ at print temp of 210C.  The disk on the end was required to get adequate base adhesion and is sanded off or otherwise removed.
 

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #87 on: March 23, 2019, 11:32:24 am »
Base part for vertical gain knob for SC 504 Oscilloscope

https://grabcad.com/library/vertical-gain-knob-for-tek-sc504-1

The files are too large to post here.

Printing this was a long exercise as the photo shows.  On the left was an attempt to mold the part.  No go with deep thin walls.  The key settings as I remember were Cura Fine print settings for base, with 92% density (supposedly optimum for strength), used PLA+ at print temp of 210C.  The disk on the end was required to get adequate base adhesion and is sanded off or otherwise removed.

Frustrating beast to get right. Some of these more fiddly ones like this and the HP knobs seem like ideal candidates for non FDM printing even if they were outsourced to a service might get a stronger more detailed result. I keep denying myself a Resin printer but if the raw material prices come down I might add one to the fleet.

Shame you need to sign your life over to Stratasys to download the files too  :-X
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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #88 on: March 25, 2019, 02:06:05 pm »
Odd.. found a file for a Wavepro/wavemaster bezel some time ago but the page is gone. I still have the files if anyone wants them but I guess there's a reason why it was redrawn so I'd rather not upload the files here...

Those who ever serviced one of those know why you'd want a replacement bezel   :-DD I actually considered having one 3D printed and perhaps order a small batch injection molded if the file was OK. If there's ever enough interest for that I may still attempt it...

Was doing some site searches here for any other lost designs and came across the owner of the missing design from Thingiverse  :-// https://www.eevblog.com/forum/testgear/restoration-of-lecroy-wavemaster-wavepro-front-bezel-by-3d-printing/msg2217930/#msg2217930

Even with the files removed for whatever Mechatrommer's reasons were the thread is worth a read.
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Offline CatalinaWOW

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #89 on: April 04, 2019, 01:58:28 pm »
It is not too hard or expensive to find the HP snap in feet used on a wide variety of small instruments including the 3468B multimeter, but it is was a fun challenge to model and print.  There are a number of functionally equivalent model numbers (at least as far as I can tell).  5040-7201, 5040-7222, 5041-8801 and 5041-9167 are ones I am aware of.

This is not an exact copy of any of them.  Changes were made to suit 3D printing and to make it easier to model.  Also the instructions molded into the foot were omitted.

Sliced with Cura, best printed feet down, 85-90% fill, with gyroid infill pattern, and zig-zag supports everywhere.  I used PLA+ filament at 210C and bed temp of 50C.  Any elephant footing will kill the ability to fit mounting holes, so if you have some trim or sand it down.

HP 5041-7201 is and .stl file, renamed to meet forum naming restrictions.  Change the extension to stl and it is ready to use.
« Last Edit: April 05, 2019, 02:31:05 am by CatalinaWOW »
 
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Offline texaspyro

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #90 on: April 04, 2019, 02:20:18 pm »
HP feet are easy to find since somebodu in China tooled up to make them...  the tilt bails, no so easy... at least the last time that I looked.
 

Offline CatalinaWOW

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #91 on: April 04, 2019, 02:33:36 pm »
The tilt bails are easy to make.  I did a couple today.  All it takes is a vise, a crescent wrench and a pair of pliers.  Which also means it is easy to make them different lengths which is good for different uses.
« Last Edit: April 04, 2019, 02:35:35 pm by CatalinaWOW »
 

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #92 on: April 04, 2019, 07:45:21 pm »
HP feet are easy to find since somebodu in China tooled up to make them...  the tilt bails, no so easy... at least the last time that I looked.

While you can buy some of them once the design is done and proven to work anyone can print a foot for under $1 and generally under an hours time.

On my list of projects will be feet for my 419A which will also suit a bunch more similar aged HP small format Gear (including my 735A currently sitting on self adhesive rubber). Also missing is the lower and side panels and tossing around Laser engraved smoke grey sides and either a printed or getting an aluminium lower one made.
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Offline nfmax

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #93 on: April 05, 2019, 02:00:11 am »
On the subject of the 419A, how about the little plastic thingummywidgets that take a PK screw and clip into a chassis hole, used to insulate Guard from Ground? My instrument is short a few, and hence not so well assembled as it used to be!
 

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #94 on: April 05, 2019, 03:11:48 am »
On the subject of the 419A, how about the little plastic thingummywidgets that take a PK screw and clip into a chassis hole, used to insulate Guard from Ground? My instrument is short a few, and hence not so well assembled as it used to be!

Won't take much to model so I will take a look when I do the feet and panels.

Interesting video on dielectric breakdown of PLA prints if anyone is interested.

https://youtu.be/ZqXQRq8As1o
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Offline JohnPi

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #95 on: April 08, 2019, 03:14:04 pm »
I worked on a similar (but simpler) push-on knob for the E36xxA (E3610A, E3620A, E3630A etc.) power supplies. These are friction fit, so take a little finessing on the sizing. Knurling on my prints is a little rough, but not so objectionable; I think I need better quality PLA. Here it is: https://www.thingiverse.com/thing:3546393
« Last Edit: April 08, 2019, 03:15:48 pm by JohnPi »
 
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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #96 on: April 16, 2019, 04:54:05 pm »
Just finalising a foot design for some of the smaller HP instruments. The one shown will suit nominal 5 1/8" wide case (735A, 327A and others) and I will be tweaking a version for the 7 3/4" wider case (419A and others).

I was going to do a version of the push in tool less clip but I have decided to go down the path of a 5mm knurl nut and button head screw. There is sufficient clearance of the head due to the design of these feet unlike the edge type feet of the same era. With the fairly tight tolerance I have used on the clip in parts it really isn't needed anyway.

For best strength on the clips it needs to be printer on it's side so as circled I have tweaked a surface with a 45 degree chamfer to reduce the supports needed.

Full Sample one is on the printer and everything being ok I will add it here later today.
I will still have a play with a rivet version and see if I can get it right too.

Edit: Off the printer and it works. Just needs a few subtle tweaks to make it work better on the printer.  :) Added a photo of the sample installed.

« Last Edit: April 16, 2019, 06:23:19 pm by beanflying »
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Offline bd139

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #97 on: April 16, 2019, 06:46:44 pm »
I'm liking this thread.

I worked on a similar (but simpler) push-on knob for the E36xxA (E3610A, E3620A, E3630A etc.) power supplies. These are friction fit, so take a little finessing on the sizing. Knurling on my prints is a little rough, but not so objectionable; I think I need better quality PLA. Here it is: https://www.thingiverse.com/thing:3546393

Just a heads up - keysight still sell those and they are probably cheaper than printing them! Think I paid less than $1 each for them last time.

@beanflying: feet on my 400E are identical to your 427A for ref.
« Last Edit: April 16, 2019, 06:50:23 pm by bd139 »
 
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Offline coromonadalix

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #98 on: April 16, 2019, 07:29:39 pm »
I like this thread too

Nice work  for the 3d printed parts, i wish i could do that  loll   no experience at all

I would love to do 2 very old buttons , they have around 2 inches long shafts, for an 57 years old Phillips vintage tube radio from my father
 

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Re: Replacement Knobs, Feet and Fittings for Test Equipment
« Reply #99 on: April 16, 2019, 07:35:39 pm »
I like this thread too

Nice work  for the 3d printed parts, i wish i could do that  loll   no experience at all

I would love to do 2 very old buttons , they have around 2 inches long shafts, for an 57 years old Phillips vintage tube radio from my father

If you still have one then epoxy is an option. Check out some of these linked youtube videos https://www.eevblog.com/forum/testgear/replacement-knobs-feet-and-fittings-for-test-equipment/msg2255121/#msg2255121

Or

If you were really keen then sharpen up some CAD skills and draw them up and get them made by one of us mob or an online 3DP source.
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