All this time I ve been thinking I needed two v-groove rails for my ROR with V-groove wheels but in a recent post I read the poster suggesting using a rail system consisting of one v-groove track and the other track just (what?) a flat bar stock. This would mitigate the situation where the two rails were not parallel. Is that what most people are doing (those that use a V-groove track and wheel system)
Obviously you would use the same wheel type on both tracks, what about the difference in heights between the flat track and the v-groove track? Resistance differences between the two tracks?
Seems like this allows you to be somewhat sloppy in constructing your gantry, on the other hand, it would allow the roof to roll off even if the tracks are somewhat skewed.