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Unread 22-12-2009, 15:17
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Jim Zhou
FRC #2198
 
Join Date: Dec 2009
Rookie Year: 2009
Location: Toronto, Canada
Posts: 29
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Re: crab drive vs. mecanum drive system

Quote:
Originally Posted by daltore View Post
3) My personal favorite. Omnidrive results in what looks like a hockey puck on wheels, it moves almost eerily, and I've played around with it on Vex many times before. If you have the wheels mounted at 90-degree angles from the center (on the front and back and the two sides), your efficiency is 100% of a two-motor drive train, in both the X and Y directions. If you mount at 45-degree angles (on the corners), you get a theoretical maximum of 70% efficiency going straight forward or sideways, but you get more power behind it. However, you will not win any pushing matches, I guarantee. It can also be a problem to mount wheels at odd angles if you go that route. Fairly simple conceptually, the code isn't that complicated (I have a library for Vex if you want to see it).
I was introduced to Holonomic drive not long ago, which might explains why I am asking you this question: How come efficiency becomes only 70% if the wheels are placed at the corners instead of being placed at 90 degrees from the center which will result in 100% efficiency?