buffing machine problem

[Alzax3]

I just acquired a fairly heavy duty buffer (like a bench grinder but with two threaded cones that you screw the calico mops onto.) It has a slight problem in that it doesn't always start (will buzz stationary, and run on happily if you give the shaft a quick helping tug.) or it will start, but isn't choosy about which direction (clock or anti-clockwise) it will go for.

It has a capacitor hidden away in it's base, and I think the symptoms point towards it as a culprit before I rush out and replace it - I was wondering if one of the experts can explain what it is or isn't doing? (is it the sign of a failing cap which is why it works some of the time?)

 

[shenion]

Could be an open capacitor.

If it has a centrifugal start switch, it could be bad. Do you hear a click as is speeds up?

 

[Alzax3]

Thanks for replying!

No, no click - the switch seems to be a simple throw on/off. So if the capacitor is 'open' it's contributing nothing at all? Or working sometimes?

 

[shenion]

The capacitor is likely open. It is used mostly during starting but does ada a small amount of torque.

If it has no start switch on the armature, then you will need run capacitor of the same value. "Start" capacitors are not designed for continuous use.