So if I cut a wheel or a gear with a central axle/hub as part of my cut, can I just fix that hub to a substrate and be confident that it with be smooth enough for the wheel/gear/whatever to rotate on? Or do I have to cut out another piece? Also, if I do that, am I likely to have it wear too fast to be useful?
Something like that. (And don’t worry about the fact that it’s not constrained in out-of-plane movement; I have ideas about that.)