A variable resistor will not change the speed of a motor.
It is intended for a light bulb.

Speed controls are for some small motors and expensive speed control
for large power motors.

I think you would want to put in a DC motor and a DC control.
Or - a variable frequency controller that are used for power motors.

Martin


KIMOSABE wrote:
I had an earlier thread asking about a Jet wood lathe, and one of the
things that people get concerned about is that some lathes do not have
a slow speed that is as slow as they would like it. Turners doing
outboard stuff seem to prefer to be able to get down to speeds in the
300's.

The lathe I'm looking at has a bottom speed of about 550.

Question: If I put a variable resistor in line with the motor to cut
the voltage when I need a low speed, would that do the trick or would
that be bad for the motor?