ideas for using regular 1/4 inch knobs with D-shaft rotary?

[ruairioflaherty]

Hey guys,

I've found the perfect knob for a project I am building (surplus) and it is a regular 1/4 knob with a screw to tighten it to the shaft. I've also sourced some grayhill rotaries that are ideal for the task but they are D-shaft.

Please excuse my ignorance if this is a dumb question but is there an easy way around this? Is there such a thing as an adapter (I imagine a semi-circular half shaft)?

thanks,
Ruairi

 

[Ptownkid]

Tighten the screw over the flat part of the D

 

[ruairioflaherty]

I guess it depends on the screw(s) being long enough to make it. If they were too short I guess I could find replacements. I found really sweet knobs and a pretty good deal on some Grayhill rotary switches so I hope I can make it work.

I'll post a link for the knobs once I'm sure I have mine,

thanks,
Ruairi

 

[BYacey]

If the setscrew is too short, slide a shim into the opening between the inside collet of the knob and the flat spot on the shaft, and tighten the setscrew against the shim. Small pieces of brass or aluminum work well for this.

 

[ruairioflaherty]

Thanks Bill,

it's all kinda obvious when you think about it,

cheers,
Ruairi

 

[drpat]

Home Depot sells set screws of various lengths...

 

[SSLtech]

No Homeopathic Despot in Ireland as far as I know...

Keith

 

[ruairioflaherty]

Thanks guys. As Keef says no Home Depot but we do have screws! My Dad was a toolmaker for 40 years specialising in custom taps, dies and all things threaded. I figure I'll just buy any cool grayhills and funky knobs I see on ebay and let him figure it all out :green:

cheers,
Ruairi

 

[drpat]

To clarify things...

Set screws are such a common hardware item, even Home Depot sells them...

 

[BYacey]

If a shim as I suggested is of sufficient thickness, a longer setscrew shouldn't be necessary.

 

[drpat]

If a setscrew as I suggested is of sufficient length, fabricating a shim shouldn't be necessary. :wink:

 

[ruairioflaherty]

If I had actually waited 'til I got my switches and knobs instead of asking dumb questions none of this would have been necessary :green: :green: