12/21/10

Modding Potentiometers to Turn Easier

What we have on the workbench here is one garden-variety CTS potentiometer.  It's here because I'm going to take it apart and 'modify' it a bit to make it turn easier.

This is actually the blender pot from my 50s Stratocaster.  It's a bit hard to turn and I'd like to get it so I can just spin it easily and quickly with my little finger.

The side note to all of this is that this sort of mod was done by the larger-than-legendary Roy Buchanan and the equally incomparable Danny Gatton to help with those volume and tone swells.  I'm nowhere in the same universe with that stuff, but if I practice it for a million years, maybe I'll get it.

You'll see this is actually pretty easy to do.  Pry back the tabs that hold the pot together (see above), and the pot comes apart as seen in the picture to the right.

We also see the main culprit in the hard-to-turn syndrome - the heavy grease in the bottom of the case.  We just clean that out, and the pot will turn much easier.  The grease is there to give the the rotation a nice, solid 'feel,' which is great for, say, an amp, but in this instance we want to be able to turn the thing with just our little finger wrapped around the knob.

Taking the grease out is a major improvement, but if you're adventurous, you can also 'despring' the wiper contacts a bit.  I just carefully bend them down a bit so they still contact the carbon track, but have a bit less tension.

Be careful here not to bend them too far so they don't make contact.  They also are a bit fragile, so be careful not to snap them off.

The easiest way to access the contacts is to just take the whole pot apart.  The wiper shaft is held in place by the nut on the threaded shaft.  If you take the nut off, the wiper will just slide out.  How easy is this?

Side note:  if you have a really noisy pot, or an old one that doesn't seem to be working, you may be able to clean and/or resurrect it this way.  This has worked for me on some old radios.  I've been only partially successful spraying cleaner into these things to clean them up.  Taking them apart is the only way to really get at the carbon track.

I also sanded a bit of the plastic rotor with some fine sandpaper (400 - 1000 grit) and did the same on the case. 

Finally, I polished up the wiper rotor shaft with fine emery paper, and did the same inside the body where the shaft passes through.  Then I put a small amount of light oil (3-in-1) on the shaft.

You can try some or all of these techniques, put the pot together, see how it works, etc., until you get it to where you like it.

Then just reassemble it and you're ready to go.

My Teles and the 50s Strat all have nice smooth, fast pots now - I need to work on the Surfcaster at some point as well.

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