dual motors

<I want to use twin motors to drive my gantry at both ends and I have
<nightmares about how open loop control could put my machine in yoga
<positions.
I have a 4' X 8' router with two motors on the X axis and one motor on the
Y-axis. I never have a problem with them getting skewed. It will run at 150
in/min with no problem. A plasma requires no force at all, compared to a
router, since it is non contact with the work, so you should have no problem
at all. What you really should be worrying about is torch height control.
If you find a cheap, automatic, reliable way to do this, let know.