Driving gantry with two paired stepper motors

I have a question concerning the use of stepper
motors to drive a gantry on an xyz table. One
problem that sometimes arises is that if the gantry is
driven on one side only, it exhibits a slip-stick
phenomena, especially if there is a cutting load
furthest away from the driven side. There are a few
solutions that I have seen. One is to use dual
leadscrews and mechanically couple the two
together, so that torque (and therefore force) is
applied to both sides of the gantry. Another is to
use two stepper motors. SuperTech uses this
technique with their XYYZ 3-axis driver boards.
They have two completely separate stepper driver
channels for the y axis.


I have seen someone suggest that you can couple 2
stepper motors in parallel on a one-axis drive. I
have tried this with a simple L297/L298 driver
board. The two motors appear to be staying in
phase with each other. I realize that you can't get
the same torque from each motor (as you would if
driven individually) but if you have a mechanical
transmission, you also split the torque.


My question: are there any potential problems with
this technique, electrical or otherwise?

-Richard-