Originally Posted by
nar
I have a new PM25mv and was gearing up to control the spindle speed from my BOB. Didn't seem to work, so got in there with a voltmeter to try to understand what's up.
I don't know if I believe the readings, but it seems that the pot is adjusting an AC voltage from the controller board. That could explain the very odd results I'm getting.
There's no way my (or any) BOB will put out AC voltage to control a spindle motor.
Anyone out there getting similar readings? In the meanwhile I've implemented a simple relay control (in the F-OFF-R circuit). Pretty easy, at least I get spindle on/off. I can dial in the speed by hand.
Sure do wish they'd publish a schematic...
Neil