As mentioned previously, changing the pulleys on the lathe may be all that is needed. That is a user operator error. However, if the pulleys still do not allow the lathe to run slow enough, a new motor may solve the problem without affecting anything else on the lathe. Assume the current motor is a 3650 rpm motor now. By changing the motor to an 1800 rpm motor, you cut all the speeds in half no matter which pulleys you are using. Go over to Google and type in "1800 rpm motor" and you will see many motors show up in price from $80 on up. In various horsepower from 1/4 to 1.5 hp. Just get one the same hp as the current motor. Hopefully the shaft will be the same so the pulleys will slide on easy. And someone will have to know something about wiring to put a cord and/or switch on the motor.