It's actually very simple. The laser is fine and the home position is at 0,0. It's the ruler's measurements that don't line up. You'd think it would be as easy as resetting home, loosening the rulers, then doing the tape thing. The problem is that the ruler's adjustability does not allow him enough play to shift the ruler along it's axis to correct the offset. The other axis' ruler should do it but he says his far left hole is not a slot (mine is so I could adjust it if I wanted to compromise my current fixtures positions).