I had it running before. The guy who had the machine before me had converted it to run on Mach 3 rather than the proprietory Denford software. I ran it on LinuxCNC and never bothered trying to get variable speed working so I don't know whether the spindle maybe always getting a constant 100V. The smoke came about when I idiotically tried to fix a disconnected wire to one of the steppers while the power was on. This blew up one of the transistors on the Baldor stepper driver board. Every time I tried to replace something or troubleshoot it with the 'scope I blew up more of the Baldor board though clumsiness, so I ended up stripping out all the original electronics and putting in new stepper drivers. In the process I disconnected the spindle and the connections between the Sprint board and the Baldor board, and when I came to try to reconnect the Sprint board (some months ago) I couldn't quite work out how to do it and I thought maybe the Sprint board was dead so I got a new (second hand) one.

In the mean time I replaced the spindle with a low powered one which has its own PWM driver, but I would like to get the original one working again