Hi all. I am doing a CNC conversion on my Harbor Freight 44991 mini mill and I want to add a spindle speed controller so that I can change direction of the spindle as well as change speed using Mach4. I have been searching for days to find a controller for this but I am unable to. The best I have found is here: https://www.ocf.berkeley.edu/~davyto...bies/mill2.htm but there are no directions or schematics to assist me in building something.

So, does anyone build, have plans, or know of how I can get control of the spindle speed and direction so that I can use the Mach 4 software in its full configuration?

If I understand this correctly, all I will need is a digital POT to control the speed RPM, and a digital switch to control the High/Low speed switch, and a digital switch to control the on/off switch of the spindle (not really required I guess).

Any help appreciated. I have done many many a search and have not found anything on this.....