After many years of good service, the DC motor on my X2 mini mill started its periodic popping and arcing.

Upon stripping the motor I found the commutator grooved so I skimmed it in the lathe, after finishing the clean up I noticed that there was no meat left for another future skim.

I purchased a brand new armature and installed it in the old casing, installing a new set of carbon brushes.

After re-installation and power on I noticed that the motor ran up to speed well but was not stable speed wise, also there is no torque on start up and minimal torque during running.

I re-installed the old cleaned up armature in order to troubleshoot and there is plenty of torque and the speed is stable.

I checked the new armature with a multimeter, the 180 degree check between segments shows good. The adjacent segment check shows good and the individual segment to laminates shows good.

Anybody any ideas.

I have since purchased a new motor and will keep the old motor with skimmed armature as a spare.

Thanks

Keith Wood

Montreal