1 Computer, 2 Machines & Mach 3

[djc]

...you won't be able to run both machines at the same time - not without some clever Gcode.

Wouldn't need to be too clever. Keep X, Y, Z for the mill and use A & B for the lathe as X & Z.

Anyway, if it's one machine at a time then you could use the same stepper drivers and just plug the motors from the lathe/mill in depending on which you're going to use. That also saves you a lot of money in stepper drivers!

So long as the settings at stepper driver level (usually microsteps and current) are the same for each machine. You don't want to be twiddling DIP switches every time you change over.

Also, at some point or other, I guarantee you will try to unplug a motor while it is still powered up. This is a VERY BAD THING. What's the additional cost of duplication? One power supply and two drivers.

Alternatively you can plug all 5 drivers (assuming 3 axis mill and 2 axis lathe) in to the computer and easily set mach3 to use the correct ones depending on if you have it in lathe or mill mode. There's lots of ways of doing it - you could have a physical switch to switch between motors or drivers.

In Mach, you just have two profiles - one called lathe.xml the other mill.xml and choose the appropriate one in Mach loader or put shortcuts to each on the desktop. If you were really smart, you could install a second parallel port and use LPT1 for the lathe and LPT2 for the mill.