I haven't set-up Mach3 on a lathe yet but, I will be soon.
Are you using a breakout board(BOB)? What type?
My BOB has to be turned on after Mach3 has started for it's charge pump to work properly..... uhgh... It took me awhile to figure that one out.
Have you configured the ports & pins, steps in the motor tuning, etc..?
I missed a few things when setting my mill up.
I must have watched the Mach3 videos a half dozen times before I got everything right.
http://www.machsupport.com/Videos/Ma...elections.html
Some good ones to watch:
Set-up & download
Inputs-outputs
Coordinate systems
Sorry I couldn't be of more help,
Jack
Walking is highly over-rated