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Unread 05-01-2009, 07:40
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Re: Frictional Discrepancies

Quote:
Originally Posted by martin417 View Post
As an engineer, I have an issue with the "lateral" and "inline" numbers. On an ideal surface, and the interaction between the wheels and "regolith" this year com as close to ideal as you can get, friction depends ONLY on friction coefficient, and normal force. There is no directionality component. I looked at the wheels, and went to Home Depot and looked at the surface. I can see no reason, theoretical or otherwise, for a difference. As AndrewN's testing shows, in-line and lateral should be identical.
My team thought this was weird as well. Our theory is that since the wheels will mostly be spinning forward and back more than they'll be sliding sideways (ignoring any holonomic-type drives), then they'll tend to get heavily scuffed in a forward-back direction. So perhaps after a few matches worth of use, you might see the kind of transverse coefficients that the manual describes.