I am new to using mach 3 and I need to create some parts, but I want to create 4 at a time. Is there a way in mach to do this. Each is 3 inches are apart on the X axis.

I would assume it would be something like this
Cut part#1 @ 0,0
move to 3,0
reset DRO to 0,0
cut part #2
and so on

But how to do that?

Use G52 or try the nesting wizard. You will find info in the Mach manual on how to use G52

Hood