I was turning down the breech end of a new barrel tonight was almost done ,when the motor slowed way down and started a nasty buzzing/ growling sound. The motor was pretty warm ,but the shaft turns freely. I haven’t found a place for brushes yet. Anybody got any ideas. The start capacitor is only for starting right? Would the switch go out while the motors turning. Thanks for any help on this, I was so close to being done,and shooting it tomorrow. thanks tz
Need some more info. What lathe do you have? Motor specs? Variable speed? If it’s just a plain ol’ AC cap. start induction motor check the bushings. Worn bushings will not allow the rotor/stator to self-align (clearances are TIGHT!) and will cause similar “locked-rotor” symptoms. You can live with quite a bit of end play but NO up/down slop! Start cap? Yes-it’s only for starting. Must be a pretty stout motor. Look for that cap. leaking oil/goo and/or any evidence stuff of getting hot. If the switch were funky you’d
probably smell it. Check for a voltage drop at the motor. There are no brushes. Those motors usually last a LONG time.
Thanks Martin, it’s an older Emco Compact 5 . No play in shaft , no burnt wire smell, shaft turns freely by hand. The motor was pretty warm! I bought it used yrs ago, have turned a few wedding bands out of hard carving wax on it over the years and have found little if any play in any of the moving parts. Speed is set by placement of belts. I don’t know, I’ll try it again in the morning,if it doesn’t crank up, i’ll take my barrel out of the chuck and check it out further. Thanks for the reply, tz