The lathe started to run 10 rpm up and and down no matter what the speed it is set at sounds like motor speeding up and down is that the photometer? I bought a new one a year ago in case it ever went out would you take the time to replace or just use like that?
Sounds like the speed control potentiometer. A part less than $5, and an easy fix. There are instructions here on the Grizzly Green Monster Group, if you want to read the thread.
Replace it - you wouldn't want it to accelerate unexpectedly.
