A few members have had a similar problem, I don't use any cam software so can't help I'm afraid but suspect you can define the base unit of measurement. I did have a different problem when I first set up Mach I inadvertently managed to switch the metric/imperial units when doing the basic set up so my machine was doing things in metric although I had written them in Imperial, I had to reload the Mach software and redo the set up. If you do that remember to save your licence file some where safe first! You program looks as if its in imperial, have you gone into edit file and changed the G21 to G20 on the set parameters line, it then should cut 2.5" square. Jim