I designed this knob for my guitar pedal builds, though it should fit any ¼" (6.35mm) potentiometer shaft. Specifically, I designed this to fit these poteiometers:

https://stompboxparts.com/pots/16mm-potentiometer-short-pcb-leg/

I designed to fit the poteiometer shaft pretty tightly (no added tolerance), so I added a couple “cut outs” to the element that hugs the shaft.

I would probably recommend printing these in a material like PETG - something that has a little flex to it and won't deform like PLA might under stress. The prints shown are in Inland PETG.

There were certain design elements that I went back and forth on:

• Did I want the position indicator to bleed over the side of the knob?
• How deep or long did I want the position indicator to run?
• Did I want any filleting to soften the edges?
• How high should the knob sit?

To circumvent the vast number of variables there could be, I've included the STEP file. Have at it.