I recently picked up a 17” Delta Rockwell 3 phase drill press that dates from the 1950s. I cleaned it, replaced the bearings in both the motor and spindle, had the chuck calibrated by a machinist, and connected it to a VFD. All was well, so I thought.

But it burns every kind of wood I try to drill. Taking the same bits to a hand drill, I get no burning at all. I’ve tried to alter the speed, but this doesn’t seem to help. Any idea what is causing this?