Author Topic: WTB Knobs for Keithley 225 Current Source  (Read 366 times)

0 Members and 1 Guest are viewing this topic.

Offline 4thDoctorWhoFan

  • Regular Contributor
  • *
  • Posts: 146
  • Country: us
WTB Knobs for Keithley 225 Current Source
« on: May 19, 2022, 08:53:34 pm »
I'm looking for some replacement knobs for a Keithley 225 current source.  I need one of the numbered knobs & a range knob (the knob on the far right).  Please see attached picture for the type of knobs.  The picture is for reference only.

The range knob will probably be hard to find but I have seen the clear numbered knobs on various vintage test equipment like on some older fluke stuff.  The center of the knob can be any color.

Thanks!

 

Offline HighVoltage

  • Super Contributor
  • ***
  • Posts: 5115
  • Country: de
Re: WTB Knobs for Keithley 225 Current Source
« Reply #1 on: May 20, 2022, 07:59:26 am »
These knobs are near impossible to find.
A few years ago I bought a second broken unit to use the good knobs and made one good unit out of two.

There are 3 kinds of people in this world, those who can count and those who can not.
 

Offline _Wim_

  • Super Contributor
  • ***
  • Posts: 1290
  • Country: be
Re: WTB Knobs for Keithley 225 Current Source
« Reply #2 on: May 23, 2022, 06:53:09 pm »
Seems possible to DIY something look-a-like, but of course quite a bit of work.

I would 3D print the acrylic discs with clear plastic on an SLA printer (via an online service). SLA will be required to be almost transparent, FDM will not work. Another approach would be to make them on a CNC router out of acrylic, but not sure if only services are easy to find for this.

I would emboss the letters into the 3D print, and then fill the letters with a white paintstick as described here: https://markforged.com/resources/blog/engraver-filler-labeling

Those disc I would glue onto a standard knob from Ali-Epxress that looks similar: https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20220523104659&SearchText=knob+potentiometer+black&spm=a2g0o.home.1000002.0

Off course, I have not tried this myself, so not sure if it would work and look ok, just this would be my way of tackling this...
« Last Edit: May 23, 2022, 06:57:11 pm by _Wim_ »
 

Offline 4thDoctorWhoFan

  • Regular Contributor
  • *
  • Posts: 146
  • Country: us
Re: WTB Knobs for Keithley 225 Current Source
« Reply #3 on: May 24, 2022, 10:21:19 am »
Yes, these knobs are impossible to find.  :scared:  :P

Also, I don't have a 3D printer or the means to try and DIY but thanks for the suggestion anyway.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf