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Unread 21-01-2014, 15:19
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Re: Plaction Vs. Banebots Vs. HiGrip friction coefficients

Quote:
Originally Posted by Madison View Post
This is a really strange way of talking about coefficient of friction. The CoF between the materials doesn't change -- it's an experimentally derived constant. I understand what you're getting at with respect to the green material -- it's capable of destroying itself. I do not understand at all what you're saying regarding the orange material.

Can you restate your observation in a manner that reconciles with physics? Can you further explain what you intend to convey by listing two coefficients of friction?
I agree. The CoF of two materials doesn't change.
Here's my thought-
When they tested the green material on carpet they found the CoF to be 2.5 when not carrying a 150 lb robot. "Of course, the material in the gree wheels begins to structurally fail at 2.0" Then, when an FRC robot is placed on the wheels, and the drive train pushes the robot forward with more than two times the force of gravity on the robot, the robot shouldn't slip due to friction, but instead the wheels fall apart.

As for the comment about orange, he may be saying that his drive is traction limited (what else could be?) so that the orange wheel (which was experimentally determined to be 2.4) could have a CoF of anything at or above 2.1 and because of the limited torque of the drive train, would never slip. That's a really weird way of talking about CoF though...

Also, a CoF of 2.4 sound really, really unreal high.