[sk8salomon]

ok, i'll check. just moved recently so a lot of crap is still in boxes. redcorn's advice about an offset value may be the ticket. usually, there are tool offsets & work offsets on a machine. the work offsets are the contact points on the fixture, say a machine vise or jig (z=zero). tool offsets are programmed as well on most CNC machines so that you can't make programming screwups and plow a drill or endmill into something and fawk stuff up. say, you have a 50mm length endmill in the spindle, you tell the machine how long the tool is and it won't let you overtravel the tool. but your machine may not have both, not sure, i'm used to large multitool machining centers.