Knob: Shaft-length Problem

[gootee]

How about just drilling a large enough hole in the panel that the whole knob will fit through? Then you can tighten the shaft screw inside the box and you won't have any visible screw holes in the knob.

I_F

Hi I_F,

Thanks. That's a good idea.

I mentioned it as an option, in my original post. But at this stage I preferred to avoid it, if possible.

- Tom

 

[gootee]

A couple thoughts- there are/were collet type knobs where you put it on the shaft, then tightened a screw in the center front. This drew up a split collet (like on a lathe) to grip the shaft. A center cap then snapped over the front. No idea where to get them, but a search might turn them up. Maybe start with Rogan. You could also get hold of the guy who posted here recently about his new metal lathe he bought for making knobs. Perhaps he could be persuaded to make you a custom, with the setscrew in just the right place to hit the short shaft. The idea of making a sleeve to lengthen the knob and bring the diameter to 1/4" for standard US knobs is appealing. If it were a good fit and installed with something like Loctite 271 or stud lock, I'd expect it to be reasonably permanent.

Conrad Hoffman wrote


they are also called....chuck type

Gajanan Phadte

Thanks, guys. Mouser.com has some collet knobs, by Rean. I ordered some, a while back, but then found out that Rean's special tool, which is needed for tightening them, is no longer available. I put them aside and now I can't find them. But I don't know if they would have worked very well, with a D-shaped shaft.

- Tom

 

[dangus]

I know there's a shaft extender in my junk box. I don't remember where it came from... probably some old-time parts place, possibly Modern Radio Labs.

One of those places that deals in small machine parts (for robots and the like) would probably have couplers. Although it wouldn't be hard to drill out a threaded coupler or hex spacer to 1/4" ID, then drill and tap for set screws. Or just glue the shafts in.