here is my mach3 zx45mill xml file
it is the complete setup and present calibration of my mill
you can unzip and copy this file to your mach3 ( c:\mach3 ) directory and as long as you are using a uc100 controller, you set all drive switches to match mine, your mill will be calibrated and ready to tune and set backlash.
when you open the mach3 loader you will see zx45mill in the list of choices
if you have the same ballscrews you will be all set to start
steve