Wheel Wear

[DonRotolo]

Our experience so far is that little bits of dirt and crud do cause some minor wear of the wheels. This is made worse by the fact that they spin so easily from excessive acceleration. The marks made tend to be along the length of the tread and not the width, but by no means would I say that they wear 'a lot' - just some visible scuffing.

In our tests on the terrazzo floor (in the hallways), waxed vinyl tile floor (in the cafeteria) and a piece of "official" pebbled regolith, the regular floors are almost twice as grippy. We pulled on a 4-wheel test platform weighing about 30 pounds with locked wheels with a spring scale. We found a small (under 20%) difference between sideways pulls and longwise pulls, so those transverse CoF numbers did not pan out for us. Also, the difference between static friction and sliding friction is measurable at about 20% (sliding being less, of course).

The custodial staff was not amused by the scuffs in the school floors the wheels left. We promised to not do it again, and they forgave us.