[MrForbes]

We're hoping to use leather for bearings in at least one part of our robot this year....

There are poured babbitt bearings, and insert babbitt bearings, and probably a few other kinds. I have worked on a few old engines that had poured babbitt connecting rod bearings. They're fun. I think my 70 year old lathe has poured babbitt spindle bearings.

But mostly, we're using ball bearings in our robot.