The handle operates the forward - reverse- stop via engaging contactors in the electrical panel which is at the tailstock end of the lathe. There's an end panel that has four allen bolts and inside the cover is the majority of the electrical system for the lathe. Could be mechanical ie. the handle isn't moving the shaft because the keyway is too worn etc, but more likely to be electrical.Is that what you do restore lathes? I have an issue with mine so might throw a question or two in here if that’s ok
hopefully will start stripping mine later, but basically it’s a holbrook lathe and to operate you lift the handle for forward and push it down for reverse.
Now it has a mind of its own and won’t be in the middle so it’s constantly spinning.
not sure what’s on the back of the handle u til I strip it, could be a cam system or some sort of clutch maybe? I can still use it but it’s a bit w**k! View attachment 1612997
Best get someone to look at it. If original that will have a 10hp motor at 415v which is pretty much instant death in the wrong circumstances.