The system I use on my rose engine enables and disables steppers to allow positioning the cutter on X and Z axes and also locking the spindle. The sliderest is positioned on a flat table instead of traditional ways, so home position isn't very meaningful. Disabling the stepper on an axis makes it easy to move either axis quickly. The firmware started as a way to control my macro panorama camera system. The movements required for a cnc mill and a camera system are very similar (if you ignore the spindle ). If you want to create a more precise movement system, investigate using an MPG to control the individual axes.