Last week I hooked up the Grob band filer to a VFD only to realize that the electric motor was locked up. The motor is mounted very low in the machine so it appeared that the basement shop had seen some flooding in the past and now things were locked up tight. I put a little penetrating oil on the mounting bolt heads and let it soak for the rest of the week. Yesterday I removed the motor and popped the casing off to find a rusted mess inside. I was able to unfreeze the commutator and then I chucked it in the lathe so I could remove the scale and rust. I was able to clean things up and put it all back together. I hooked up the VFD and the motor worked great. I reassembled and mounted the motor back in the Grob and I now have a functioning Grob filer. I'll have to snap some pics of the piece of steel I filed with it. It's so smooth and even; such a cool piece of equipment.