Following the kind directions given by Jim Rozen and others, I twiddled with that DC drive and motor this evening. The motor checked out, about 50 ohms on the armature, and a rather odd reading on the field, but not shorted and no shorts to ground were found.
However..the drive unit is toast. The variac is shorted and inspection with a flashlight showed multiple blown and burned sections on the winding, so I didnt even bother going any farther. Shrug..replacing that bastard will cost more than a new drive.
While sitting thinking about the problem..I sorta kinda recalled there being a DC drive unit or two in that Pile of Stuff thats filling my back yard (still..sigh).. With a flashlight and rain coat, I burrowed under the tarps, into a number of piles and ultimately found a Cleveland Motor Controls Pacemaster1. No case, and no idea if its any good. I downloaded the manual from CMC, read the specs..and it seems that it will work with the motor. Ill bread board the bugger up and if it works ok, Ill have to make a remote control unit, mounted to the outside of the grinder, and mount this unit inside the base.
I think I have all the bits to breadboard it up, with the possible exception of a 1k pot..but Im sure I can part something out and snag one..
Ill let you know how it goes, and thanks Everybody for the help.
Gunner
'If you own a gun and have a swimming pool in the yard, the swimming pool is almost 100 times more likely to kill a child than the gun is.'" Steven Levitt, UOC prof.