Hi,
when homing Mach advances to the switch in the programmed HomeDirection, at the programmed HomingSpeed until it hits the switch. It will then back off the ONLY as
far as is required for the switch to deactivate. Depending on your switches it could be that they have half an inch of hysteresis and you can't change that.
I use roller plunger snap action microswitches which have 0.05mm of hysteresis, and due to the mechanics of the roller plunger and the ramp against which they operate
they back up about 0.8mm. The home switches allow me to home to within 0.02mm every time and have done so for years.
What sort of Home switches are you using? Could they have 0.5 inch hysteresis?
Note that some motion controllers allow you to program a certain distance OVER AND ABOVE the normal back off distance, but only some controllers. What controller are you using
and does it have that programmable BackOff feature? If so it may be mis-programmed.
Craig