I have been thinking about how to rebuild the big box frame to be more ridged but this could apply to any printer. If one were to make modification to minimize flex in the rods I see that a lot more inertia exspecially effecting the Y. To combat this I am sure a larger stepper could be used, but what about splitting the Y between two seperate steppers like the Z. Is this not done becuse it's easier for the steppers to loose sync when powered off or is there something else? What would be the best why to increase the power of the Y axis to compensate for the extra weight? Can a second stepper be added to the opposite side and tie it in to the existing Y axis drive system or would the two steppers just be battling each other? I was thinking if Y axis was powered before tightening the set screws on the second pully that they would be locked in phase with eachother.