I have carved two different, yet similar models, in both cases I first carved with Vectric Cut3d and Vectric Aspire, to generate the G code, and mach3 to control de mill, and in both cases the upper (furthest from the Y origin) edge of the pieces is off by a cuple milimeters (less than 1/10 inches) I have checked the calibration of the mill, and it does not amount for such a great difference. Could you tell me what could be causing this flaw?