I have mach 3 running on generic Chinese cnc mill which has been calibrated for axis movement. With gcode output from Aspire, I tell it to create a square 25mm x 25mm x 5mm deep, the square comes out at 23.6mm square and 4.9 deep. I have measured axis movement of 150mm using MDI and that measurement is spot on. I'm thinking there's a setting in mach3 that I am missing. Any help greatly appreciated.