[echin]

Thanks for the suggestion on the plates. I just changed the top and bottom plates and cut out almost .5 lbs total.(per module) I have been thinking about more compact cylinders, but I can't decide what to use. A final version will probably have something much smaller. I thought that I had a spacer underneath the sprocket, but looking back apparently I didn't...
The bearings are needle bearings and are mounted between two flat plates to give them a flat bearing surface. The entire caster is held on with several stop collars to prevent the caster from bending.