A Guitar And Gear Support Forum

You found the perfect knobs for your #1 guitar, but they go on a bit loose. What do you do to make them fit better? I've heard people suggest cramming a screwdriver in the slit of the pot to crank it wider, but I've also heard of that breaking pots, so no. I'm resorting to cutting the tip off a plastic straw to wrap half the top of the pot, and that seems to work really well. But I imagine there are a lot of other solutions out there. Please share one!

I've done the screwdriver thing and never broke a shaft, but I understand your concern.

I've also done something like your straw technique, except I used a snippet of rubber band. It both compressed and gripped onto the knobs really well.

I've also used aluminum foil and a piece of paper towel.

I HAVE broken a pot shaft while prying with a screwdriver. I have also used aluminum foil and I have stuffed a sliver of wood into the shaft slot. I had the best results with that last trick.

But I just might try the OP's straw technique!

My Peavey Bandit had a broken pots I suspect from people trying to bend out the shaft as the knob was loose as a goose when I got it from Goodwill. Found a tab was cracked and as soon as I put a little side load the casting broke completely. I stuck the broken piece inside the knob and used hot glue to fix. I gave it a squirt and stuck it back on as straight as possible. The hot glue doesn't really bond to the metal or plastic permanently, but perfectly takes up the space. I can pull off the knob and replace the hot glue or maybe I will replace the pot like I did with the couple that had been completely snapped off and I had to replace with a similar yet far cheaper pot (FWIW Peavey pots are stupidly overpriced for what they are).

Good stuff, keep them coming! After the hot melt glue idea, I thought maybe heat shrink tubing instead of the straw tip, so I'll probably try that too. But I'm sure there are more ways still. Thanks.

I can't say i have run into this. Sounds like it's not the proper knob or the split splines were crushed together. Usually it's the other way around as i can't get the knob off the pot.

The problem with a screwdriver is you are prying in one direction or the other in a lever action that puts much stress on the shaft hence the breakage. Try a small chisel blade as a wedge action that pushes each side of the shaft in the opposite direction. It sort of equalizes the pressure and should work just fine. I dare say the whole reason for the slot it to spread just the right amount so the knob is snug. I do know there are knobs with a sleeve built in that recesses into the slot as well. I have only seen a few of those and it has been many years since I have seen one.

tonebender wrote: ↑Thu Jun 12, 2025 7:51 am The problem with a screwdriver is you are prying in one direction or the other in a lever action that puts much stress on the shaft hence the breakage. Try a small chisel blade as a wedge action that pushes each side of the shaft in the opposite direction. It sort of equalizes the pressure and should work just fine. I dare say the whole reason for the slot it to spread just the right amount so the knob is snug. I do know there are knobs with a sleeve built in that recesses into the slot as well. I have only seen a few of those and it has been many years since I have seen one.

I agree and use the wedge technique, when I try with a screwdriver. But be aware that the shafts on the pots of lower cost instruments are sometimes pot metal, which doesn't stretch/bend gracefully. Don't ask me how I know.

mozz wrote: ↑Thu Jun 12, 2025 5:41 am Usually it's the other way around as i can't get the knob off the pot.

I've had a bunch of those too, and agree they're worse. I've even ruined a pot, pulling the shaft clean out just trying to remove a knob, and that's horrid.

I'm thinking the heat shrink layer would be the best, but it might be too thick, I would try Scotch tape or electrical tape.

Edit: Waiting for Tonrays ghost to give us his solution when you have loose knobs. Maybe not, strike that.

I've gotten pretty good at the screwdriver into the slot, with one particular blade driver that acts as a wedge. For pots which have been corrupted by others before me, I've used blue tape, the hot glue method described by @honyock and dipping the shaft in butcher's wax, then filling the knob shaft-receiver 1/3'd way with 5 minute epoxy mixed 35% hardener and 65% resin. The trick to the latter is to turn the guitar facing the floor so the epoxy doesn't drip into the pot or on the guitar before drying. Due to the mix imbalance the fit is forgiving and due to the wax, it can eventually slip off the shaft if needed.