You cant go wrong with the MSD980, it is most likely one of the best drivers in its class in the market.
The motor is an old MAE motor and the current is 3.1A Unipolar (I beleive) so that works out to be 2.2A in series and 4.4A in parallel.
I would measure the resistance of the phases and they should be 0.9 Ohm.
Also check to see if you are getting shorts between shases and to the motor body, just incase you fried it.


Quote Originally Posted by bobin View Post
hi gary thanks for the info on steppers wiring....motors are from and for(a denford cnc lathe ORAC they are italian motori hy200-3424-310-a8 )and can be run at 90 volts...we were testing them out on routout 10 amp boards when we blew the lot...repaced the mosfets on the boards,but driver chip has number rubbed off so cant source replacements..so we have bought motion control msd980 driver boards these will also work up to 90 volts(will have to look at your site to see what you have..but this time the driver boards have more protection..and we will be a lot more carefull setting currents..thanks again(ps gone to your site now)