[summetj]

I have a Denford MicroMill 2000 that uses a Balfor NextMoveST motion control card. I have removed the top card and am successfully moving the axes using a parallel port break out board connecting directly to the Step and Direction pins on the bottom stepper motor driver card.

Lots of pictures, videos, etc here:
micromill | Jay's Technical Talk

The machine uses a KB spindle motor controller board (0-10V speed input), and the nextMoveST bottom card has the circuitry needed to drive it, but I haven't been able to figure out how to make use of it via the 96 way DIN connector. If anybody has any information about how to enable PWM speed control using the existing NextMoveST bottom card I would appreciate any information.

Alternatively, I might be in the market for an isolated DC/DC supply type PWM to 0-10 volt conversion board.

Thanks,
Jay

[summetj]

Update, I figured it out. It requires a bit of circuit bending (remove surface mount resistor R29 to disconnect Pin3 of the optoisolator from the normal drive circuit, solder a 200-220 ohm resistor to pin 3 and drive that (active low) from the parallel port breakout card.

Details here:
How to convert a Denford / ScanTek 2000 Micromill to LinuxCNC / Mach3 control: Part 4 – Spindle Speed Control | Jay's Technical Talk

Jay