John Rutoskey wrote in 990810 MMDigest:

> Remember that in replacing the idler wheel, the only thing that
> matters is that the wheel fits on the mechanism's shaft.  The actual
> outside diameter of the idler wheel does not matter.

That's true, but the replacement idler should be fairly close to the
size of the original so that the idler can properly wedge itself
between the motor shaft and the turntable rim.  There's a company in
Whitewater, Wisconsin USA, called variously "Premium Parts Plus" or
"Projector Recorder Belt Co." or "PRB Inc.", which can supply weird
idler wheels.  Or, if you've got a real antique, they can rebuild your
old one.

When you're working on an old turntable, be sure that the motor shaft
is clean and does not have a layer of gunked-up rubber built up on its
surface.  This will cause strange speed variations.  If, on a multi-
speed turntable you find that the idler wheel does not line up with
the steps on the motor shaft, the problem is probably that the rubber
grommets that support the motor have deteriorated, allowing the motor
to drop.  You can buy new grommets or make new ones from rubber tubing.

Mark Kinsler
http://www.frognet.net/~kinsler