Do you plan to use the same stepper drivers too? Same BOBs?
I use the same computer, drivers, BOBs to operate two Sherline machines. They both have the same type steppers mounted so the drivers do not have to be adjusted for different motor requirements. I use a set of TYCO CPC connectors to plug in either the mill (and harness) or the lathe (and harness). Just swap cables and open the appropriate Mach3 profile.
My system actually has a router I can swap out too, that uses the same type steppers. Very modular set-up.
B3030