[pntbll1313]

Originally Posted by Siri

...Are you saying you don't slip your wheels (or rollers) when you strafe into a colson/nitrile tank drive?

I'd take those equations: a tank's going to have basically double your CoF. AM lists their mecanum as 0.6 sideways (0.7 axial), and we've got nitrile at around 1.2 AM puts HiGrips a bit lower, while VexPro puts Versas right there. Colsons are even higher--I recall people modifying colsons to like 1.5. (EDIT: colson link)

We don't have a practice field or correct carpet so we haven't done any of the specific tests you're talking about. All we have is evidence from match videos that we are tough to push sideways when we apply force in that direction. We also haven't really investigated the different material of wheels of robots after they attempt to push us. I would guess that yes our rollers do slip some as we drive but sideways into a robot trying to push us from the side. We've never got into a direct side pushing match where someone started to push us and we applied a force and still slid, which would get our wheels into more of a kinetic friction.

That actually just made me think of another point. We were playing defense once (we don't do it too often remember). But a robot was using a ramming technique to break our static friction and every time they backed up to ram we drove sideways towards them and actually gained ground on each hit haha.

I'm not claiming mecanum is better than the higher traction tank drive bots at sideways collisions, they're almost certainly not. What I was saying is that it's tough to add in force of the mecanum in the sideways direction, along with static friction of the rollers, along with slipping of the rollers, and get a correct equation for mecanum because I don't have those numbers. I bet every team has a different slip in their rollers making it hard to calculate as well. I do think that our mecanum was better than many of the robots we faced at taking sideways hits. Some of the mecanum bots were much, much worse at taking sideways hits than tank robots so that's not a blanket statement. Those robots are probably the ones people picture when they think of collisions as well. Maybe in the off season we can do some testing