I have a couple of small steppers -- 20 oz in or thereabouts -- that I think
would serve dandy as force feedback motors in a custom jog shuttle
controller. I want the shuttle wheel to resist turning proportionally to the
mill's stepper current draw (or torque, or whatever meaningful measure there
is of how hard they're working). It doesn't have to be very precise, but
precise is good also.

How do you control a stepper in this fashion? Operation will mostly be in
quadrant 2, plus return to center when it's let go. I think I would like it
to be switchable between operating in velocity mode -- turn more to go
faster -- and position mode, emulating a hand wheel or crank.

Any thoughts on how to do this? Or which of the many boards or newsgroups
might discuss something like this? I realize I might have to program a PIC
to do this on the cheap, but off the shelf would be nice too.