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Knobs that don't break my pots

Schonbrun

Schonbrun

Mar 8, 2020
59
63
#1
The last time I worked on my bass, I ruined a pot just by taking the knob off it. The shaft pulled out of the body a little bit, but enough so that it now turns forever and won't push back in. This has happened to me twice now.

How can I avoid this mistake in the future? Are there knobs that don't grip so hard that I risk this every time? Can I lubricate the inside of the knob? Was I too brutish getting the knob off?

I've included pictures of the knobs that have caused me this heartache as well as the broken pot next to a functional one.
 

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#10
Lownote38 said:
Pliers? Bad idea there. You need a knob puller that doesn't put pressure on the shaft of the pot like pliers do.
Click to expand...
Unfortunately, unless the puller can grip the shaft of the pot independently of the knob, pulling a splined knob off a splined pot shaft will put pressure on that pot shaft even using a puller. If the knob is glued on by sweat grime and time, there's a good chance your knob and pot will become a single use item if removal is attempted. My basses all have solid shaft pots, even the one that came to me with splined shafts, but after breaking 2 out of the 3 witch hat knobs trying to get them off, it was easier to just replace the pots with solid shaft versions and set screw knobs.
The big problem for me with splined shaft pots and knobs lies in the fact that there are 2 diameters and spline counts used in basses. I can't recall off the top of my head which is which but it pretty much comes down to country of manufacture on the pot as to which spline count you'll wind up with. The other PITA associated with splined knobs is most are made offshore which means they are made to metric dimensions which is usually OK for most stuff but since splined knobs are an interference fit in the shaft, the slightest variation results in a wobbly knob or one you have to force on it's shaft. Not to mention most retailers don't publish spline counts or even shaft diameters for which their knob offerings are made.
With solid shaft pots and knobs it's all the same, with the exception of offshore knockoffs made to a metric standard to fit a standard shaft. You will find most of these are 6mm which converts to .24", which is an RCH small for your typical .25" solid pot shaft. Sometimes they fit, sometimes not so no matter how you slice it. Pots and knobs can be a major PITA to get both the pot and knob you want rather than having to settle for whatever works together.
 
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#13
fhm555 said:
Unfortunately, unless the puller can grip the shaft of the pot independently of the knob, pulling a splined knob off a splined pot shaft will put pressure on that pot shaft even using a puller. If the knob is glued on by sweat grime and time, there's a good chance your knob and pot will become a single use item if removal is attempted. My basses all have solid shaft pots, even the one that came to me with splined shafts, but after breaking 2 out of the 3 witch hat knobs trying to get them off, it was easier to just replace the pots with solid shaft versions and set screw knobs.
The big problem for me with splined shaft pots and knobs lies in the fact that there are 2 diameters and spline counts used in basses. I can't recall off the top of my head which is which but it pretty much comes down to country of manufacture on the pot as to which spline count you'll wind up with. The other PITA associated with splined knobs is most are made offshore which means they are made to metric dimensions which is usually OK for most stuff but since splined knobs are an interference fit in the shaft, the slightest variation results in a wobbly knob or one you have to force on it's shaft. Not to mention most retailers don't publish spline counts or even shaft diameters for which their knob offerings are made.
With solid shaft pots and knobs it's all the same, with the exception of offshore knockoffs made to a metric standard to fit a standard shaft. You will find most of these are 6mm which converts to .24", which is an RCH small for your typical .25" solid pot shaft. Sometimes they fit, sometimes not so no matter how you slice it. Pots and knobs can be a major PITA to get both the pot and knob you want rather than having to settle for whatever works together.
Click to expand...
The answer to 6mm shafts and 1/4" knobs is an adapter sleeve. Also works on 6mm splined shafts where you want to put a set-screw knob.

EP-0220 Brass Pot Sleeves
 
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#14
Turnaround said:
The answer to 6mm shafts and 1/4" knobs is an adapter sleeve. Also works on 6mm splined shafts where you want to put a set-screw knob.

EP-0220 Brass Pot Sleeves
Click to expand...
I've used them and they fit the pot shaft just fine but were too big for the knobs I had. I also tried the little brass plates used to fill the slot in a split shaft pot so you can use solid shaft knobs on splined pots. They worked as far as the knob not just falling off, but the knobs sat crooked and my OCD lit up like a Christmas tree any time i looked at or used my wobbly knobs.
 
#15
Well it turns out that not all sleeves are equal. I make knobs and they are all drilled out for 1/4" shafts. With each set I include sleeves that allow them to be used on 6mm posts and splined shafts. All have fit both the knobs and the shafts perfectly. Now I have to try to remember where I bought these sleeves so many years ago.
 
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