HiGrip wheel

[tim-tim]

Does anyone know what the Coefficient of Friction for the HiGrip Wheel is normal to the direction of travel? I know AnyMark has 0.95-1 listed as the coefficient of friction for the wheels; however, I don't know if that is for the direction of travel exclusively or both.

Or is there an effective coefficient of friction due to the "biting" in the carpet normal to the direction of travel? Essentially in an equation what do I use for Mu_x (direction of travel) and Mu_y (normal to direction of travel)?

**A bit off topic from what the OP has started**

[Wren Hensgen]

An interesting side note. Team 225 had a KOP 6-wheel chassis, with 4 inch wheels to help keep our center of balance lower. However, we discovered at our first competition that the sharp edges of the wheels mean they bite into the carpet when pushed sideways, which contributed to our tipping in a couple matches. Roughtop wheels move sideways more easily, which helped us stay up.

5545, a rookie at our first event also had an issue with them. They were a defensive robot that got slammed around a lot, and they managed to shatter the center of the wheel so that the bearing had nothing to sit in, and they flopped around the axles.

[Pault]

I am very surprised to see so many complaints with the HiGrip wheels. Team 3958 really loved using them this year. We had them in a 4wd with a wide (32x24) robot. Turning was very easy because of our short wheel base, and our robot was really good at pushing and resisting getting pushed. The first half of this video is a good example.

We can't really speak for durability. We had absolutely no driver practice during the build season, and we missed half of our matches during our first of two competitions. We also did not make it into eliminations for our first competition. And because we were a floor pickup robot, we were not subject to lots of crossing the field at full speed. So we were not putting the wear on our wheels that most teams were.