Doing a lot of research for my next build. The designs I am considering are the MechMate and the Joe's 4x4 Hybrid. Both use v-groove bearings on angle iron rails. The MechMate uses larger bearings than Joe's 4x4 and thicker (1/4") angle iron. The rails are ground to match the v shape of the bearings.
Are the rails in Joe's 4x4 ground to fit the bearings?