Hi,
that's good, you are referencing your machine. Now jog to the corner of the part and use the 'Zero X', 'Zero Y' and 'Zero Z' buttons alongside the
DROs. That will set the work offset.
1)Reference your machine- the DROs display machine co-ords 0,0,0
2) Jog to the corner of your part 110,140,-75 say in machine co-ords
3) <zero x> <zero y> <zero z> now DROs display work co-ords 0,0,0
Note the machine still believes it as at 110,140,-75 in machine co-ords its just that you specified that location as convenient as 0,0,0 for your part.
If you look on the machine diagnostics tab you will see how Mach works out its current position. If you look on the offsets tab you will see that
Mach has stored those numbers as a set in G54 or G55 or G56....
Craig