I have recently converted an X2 mini mill to CNC, using a simple split nut mod for anti-backlash. After an entire week of tweaking I am now seeing backlash of .0003 - .001 across the entire travel of the x axis, however the first 3 inches (on the left side of the table) has a noticeably larger backlash of around .003.

The problem is Mach3 only seems to allow me to enter one value for backlash compensation. Should I just do all my precision work on the right side of the table or is there some better work-around for the inconsistent backlash?