Adapters For D-shaft Pots?

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: luketeaford, Joe., lisa, Kent

Post Reply
User avatar
glennfin
Veteran Wiggler
Posts: 558
Joined: Sun Apr 19, 2015 1:19 pm
Location: Winston Salem, NC
Contact:

Adapters For D-shaft Pots?

Post by glennfin » Tue Jul 28, 2020 9:04 am

Is there such a thing?. To convert D-shaft to round? I know they exist for knurled shaft pots (out of stock at small bear)
but hoping there is a solution for D-shaft. I know I can mount a round knob on a d-shaft but that out of round travel is no good. :eek:

Thanks

jorg
Veteran Wiggler
Posts: 738
Joined: Fri Apr 03, 2015 9:38 am
Location: East Coast USA

Re: Adapters For D-shaft Pots?

Post by jorg » Tue Jul 28, 2020 11:06 am

Oddly, I can't find such a thing. It seems like it could be a very simple thing. Take a piece of rod stock (chunk of excess potentiometer shaft?) and file it flat. Or maybe glue a piece of toothpick or something in place, just to fill the gap.

User avatar
ersatzplanet
Synthwerks Design
Posts: 6565
Joined: Fri Mar 06, 2009 1:18 pm
Location: Seattle WA

Re: Adapters For D-shaft Pots?

Post by ersatzplanet » Tue Jul 28, 2020 11:44 am

Flatted shafts come in a variety of different configurations so a universal adaptor will not be completely possible. The flat orientation can be spaced on the pointer side or the opposite side. The flat length can very dependent on the knob used, to stop the knob from bottoming out on the front panel if it has a collar. The depth of the flat into the shaft is spec'ed different from 2-3 different standard depths. The shaft itself can have different diameters.

The easiest way to use a non-flatted knob on a flatted shaft is to use a collet knob which will ignore the flat entirely. These are more expensive knobs though. If you are lucky, you can use a set screw knob if the set screw happens to align with the flat on the shaft and is long enough to reach it. I use them all the time on some of my products that have flatted shafts. Set screw knobs with metal inserts work best for this. I use a Davies clone that is perfect for this. If the flat is too deep, a metal shim can be put in the space to make it work. This will also work if your knobs were designed with a shallower flat in mind.

Knurled shafts/knobs are not universal either. There is a 10 degree difference between pots made to mount vertically and those made to mount horizontally. You can see this on older Doepfer modules that used the same knobs for both PCB orientations. A set-screw know will work with those too if they are snug enough. The pots on my modules are either knurled or flatted and I use set-screw knobs on both of them with success. Assemble time is a bit longer on the knurled ones ro align the pointers correctly of course.
-James

James Husted - Synthwerks, LLC - www.synthwerks.com - info@synthwerks.com - james@synthwerks.com
Synthwerks is a proud member of the Mostly Modular Trade Association (http://www.mostlymodular.com).
Always looking to trade for Doepfer P6 cases

User avatar
glennfin
Veteran Wiggler
Posts: 558
Joined: Sun Apr 19, 2015 1:19 pm
Location: Winston Salem, NC
Contact:

Re: Adapters For D-shaft Pots?

Post by glennfin » Mon Aug 03, 2020 10:44 am

Thanks James for "everything you always wanted to know about pot shafts"

I appreciate the info. 8-)
ersatzplanet wrote:
Tue Jul 28, 2020 11:44 am
Flatted shafts come in a variety of different configurations so a universal adaptor will not be completely possible. The flat orientation can be spaced on the pointer side or the opposite side. The flat length can very dependent on the knob used, to stop the knob from bottoming out on the front panel if it has a collar. The depth of the flat into the shaft is spec'ed different from 2-3 different standard depths. The shaft itself can have different diameters.

The easiest way to use a non-flatted knob on a flatted shaft is to use a collet knob which will ignore the flat entirely. These are more expensive knobs though. If you are lucky, you can use a set screw knob if the set screw happens to align with the flat on the shaft and is long enough to reach it. I use them all the time on some of my products that have flatted shafts. Set screw knobs with metal inserts work best for this. I use a Davies clone that is perfect for this. If the flat is too deep, a metal shim can be put in the space to make it work. This will also work if your knobs were designed with a shallower flat in mind.

Knurled shafts/knobs are not universal either. There is a 10 degree difference between pots made to mount vertically and those made to mount horizontally. You can see this on older Doepfer modules that used the same knobs for both PCB orientations. A set-screw know will work with those too if they are snug enough. The pots on my modules are either knurled or flatted and I use set-screw knobs on both of them with success. Assemble time is a bit longer on the knurled ones ro align the pointers correctly of course.

omega8870
Learning to Wiggle
Posts: 10
Joined: Sat Aug 18, 2012 4:03 am
Location: SoCal, USA

Re: Adapters For D-shaft Pots?

Post by omega8870 » Mon Aug 03, 2020 11:24 am

https://lovemyswitches.com/potentiomete ... t-adapter/

Depends on exactly the dimensions of the potentiometers, but I put significant effort to ensure my DIY pots are 1/4" or 6.0mm shafts and use these adaptors if I wanna try different knobs.

Post Reply

Return to “Music Tech DIY”