I have Mach 3 running my homebuilt mill and I have added a HF lathe bed, headstock and tailstock ala Tormach . The headstock is driven by a large stepper motor with timing belt reduction and works fine as a 4th axis. It reliably positions and runs the spindle at 600 rpm. However I'd like to be able to run it as a lathe with the stepper running continuously, as I have a Tormach QC Tool Post mounted behind the mill spindle. However my set up is a Xulifeng USB motion card with 4 axis and supports only a pwm spindle. Mach 3 supports a stepper or servo spindle using step and direction, however I can't see a way to make the outputs from Mach 3 use the 4th axis outputs of the Xuifeng card as the spindle. Anyone know how I might do this? Alternately I am thinking to add a pulse generator to generate spindle speeds and put an encoder on the spindle for threading.
At this point I am so close, and so far!