I think - after looking at the first designs - that I`d still prefer to have an inner gantry plate - to maintain the rigidity. Having both sets of wheels within the C section - although it would be good for keeping the muck from the wheels - appears to me - to give a bit of a pivot point because both sets would be so close together. I think - a set of wheels top and bottom - as usual - and an inner gantry plate would meet all criteria. Giving a strong Gantry and leaving more room for a larger screw - or rack and pinion within the C - is what this new C Section is all about. How say you. Gray P.S. Isn`t a - C section - to do with giving birth. Perhaps we are! New Ideas!!