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!!
Gray, it all depends on the forces and how they are applied. You would never use the inner wheel mounting the Z-axis carriage to the X-axis as the eccentricity of the router causes the assembly to roll about the X-axis. There you want as wide of a spread as possible. But at the Y-axis rails it really doesn't matter which you use. The stiffness of the gantry beam keeps the side plates from rolling outward and thus the load on the wheels is largely vertical with a small amount of lateral force but no outward rolling. Inset wheels are perfectly fine there. But when you start talking inner gantry plates, you are talking about an entirely different issue. Inner gantry plates are there to reduce the flex in the wheel screws thus increasing rigidity.
