I am wondering if your power source could have something to do with your issue. Amp drop can affect motors.
Running equipment on too long of an extension cord or too small wire size for the distance........SMOKE and Fire BAD!!!!!!!
I have seen many skill saws burnt up from running 200ft on 14 gauge wire on the same 15amp circuit as a small compressor.
Brent
A,B machines, PE,probe,conforming vectors, centerline, 2d,3d,stl and dfx imprt, rotary , 3.xx, Pattern Sculptor
OS X Yosemite
Woodwork is what I do to pay for my tool addiction.