Knob with too big a hole.

[Axtman]

I bought two knobs for vintage Peavey amp I am working on. It turns out the knob is for the larger diameter shafts for pots. The amp I have has smaller diamter pots.

Any ideas on how to fill the holes in the knobs to fit my pots?

[xtian]

Poster tack. It's like putty, sticky but easy to remove when desired.

https://www.amazon.com/Adhesive-Mult.../dp/B09NNRD7GJ

[The Dude]

Yes, whatever you use, make sure it's easily removed. I once worked on a 32 channel Mackie board. The knobs kept coming off, so the customer superglued them on. THAT was fun.

[Helmholtz]

What is the diameter difference?

There are reducing adapter sleeves/bushings made from thin wall brass tubes.

https://www.tube-town.net/ttstore/po...uf-6-3-mm.html

[Mick Bailey]

If the knob is 1/4" and the shaft is 6mm I either use thin heatshrink or a couple of wraps of masking tape. If they're 4mm shafts and I have 6mm or 1/4" pots I have brass tubing to make up the diameter. Anything else and I machine a length to fit, as when I needed to fit 6mm knobs on 2mm shafts.

[Tom Phillips]

In addition to the previous recommendations I offer the following links to various sizes of pot shaft adapter hardware
https://www.tubesandmore.com/product...s-125-shaft-14
https://www.tubesandmore.com/product...r-18t-shaft-14
https://www.tubesandmore.com/product...-4mm-shaft-6mm

[Tassieviking]

https://lovemyswitches.com/potentiom...shaft-adapter/

[Axtman]

I appreciate all the suggestions. My bad for not further explaining that the pot shafts were knurled plastic.



I am nervous about trying shrink wrap tubing for fear of melting the shaft. I tried masking, friction and electrical tape. It held the knob but if you turned the knob with a little bit of pressure it spun when the pot stopped.

I am toying with the idea of filling the hole with an epoxy then drilling out the center. Hopefully the epoxy with have just enough give to hold the knob and not spin when the pot stops.

[Tom Phillips]

...My bad for not further explaining that the pot shafts were knurled plastic....

The adapter at https://www.tubesandmore.com/product...r-18t-shaft-14 shows a thin sleeve on a knurled shaft. I believe that one or a similar solution would work for you.

[Helmholtz]

Nor clear:
Are your new knobs meant for a wider knurled shaft or do they use a fastening screw?

[Axtman]

The new knobs are meant for a wider knurled shaft.

[Helmholtz]

The new knobs are mean for a wider knurled shaft.

Now that's a real problem and none of the proposed solutitions might work satisfactorily - except maybe thin electrical tape.

[mozz]

I probably have those original knob. Send me a message.