1/4" vs 6mm. A question of knobs and shaft-diameter

[Auke Haarsma]

I have quite a bunch of 6mm alpha-pots. Now I'm looking for chrome knobs, which are pretty expensive (I need ~50/60 knobs). I can get them from Ebay...but they are made for 1/4" pots (which actually is 6.3mm, right?).

Does anyone know a solution to cover the 3 mm difference between my pots and the knobs diameter?

[d95err]

If the knobs have a set-in screw then it's usually allright. It would be more difficult the other way around (1/4" shaft and 6mm knob).

[Auke Haarsma]

yeah, they have a screw. I'm looking at these knobs:
Ebay-link

[Auke Haarsma]

I've orderd two knob types in small amount. Safest way to see if they fit

[The Tone God]

1/4" is actually 6.35mm. If the knobs are set screw then you should be fine but the knob will have a mild wobble when doing full turns due to be slightly off centre.

Andrew

[puretube]

0.35mm, not: 3mm difference...

heatshrink tube or cellotape ("isoleerband"),

or a cut off of a "flap" of a cigarette-paper "enclosure" (e.g.: "Mascotte" or even: "Rizla"...)
wrapped around the shaft will take care of the gap.

[gez]

heatshrink tube

Now that is a good idea! 

+1 Beer Token for you...

[Paul Perry (Frostwave)]

I have not had very good success with heatshrink.
It's kind of soft & when you tighten up the set screw it sort of squashes to one side.
Maybe it is better than not using heatshrink at all, but it wasn't a real win for me. Maybe others will have more luck!

[Auke Haarsma]

That's exactly what I would expect. Heatshrink looks like it's gonna be to weak.

But the idea of increasing the diameter of the shaft seems the way to go. Now I'll just have to find the right material for it.

I don't have the knobs which I ordered as samples in yet, but will ofcourse test (with heatshrink too) as soon as I have them.

[Auke Haarsma]

0.35mm, not: 3mm difference...

Even after reading your post I didn't realize this. Now when I re-read your post... indeed it's not a 3mm gap, *just* a 0.35mm gap.

[Ry]

I have used plumbers tape (the very thin white stuff) for things like this.  I wrapped it around the pot shaft until it was the correct diameter.  I didn't have a problem with it being too squishy.