Jeremy

If the gantry can be stiff enough to resist torsion on the XY-plane around the driven side in response to forces on the cutter then it can be done. What were you planning to make the gantry from?

ideally the drive should be outside the X-axis linear rails so that the turning moment due to the cutting forces moment acts primarily on the linear bearing and not on the leadscrew. With a cutting force of 50N (MDF or very light cuts in ali) at 300mm radius (assuming 600mm Y-rails) the turning moment is 15Nm.

By way of example, assuming 16mm fully supported rail on 40 x 30 x 3mm wall box sections 200mm spaced the deflection in the X-direction at the non-driven side will be ~.06mm (so .03mm at the cutter) and in the Y is .001mm. This shouldn't cause any material binding on the rails.