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Unread 12-04-2014, 14:22
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Re: Swerve Drive vs Mecanum Wheel drive?

Quote:
Originally Posted by Ether View Post
There is a world of difference in traction between a good and a bad mecanum drive. Proper design and craftsmanship are crucial to traction for a mecanum.
I don't understand how the same 4 wheels touching the ground in a static state could possibly have different amounts of traction.

Quote:
When the vehicle is going at a 45 degree diagonal (i.e. perfectly perpendicular to the direction of rotation of the rollers), the rollers do spin.
How can a free wheel be forced to spin when going perfectly perpendicular to it's direction of rotation?

Quote:
The only time the rollers do not spin1 is when going forward and backward, is which case the vehicle is not going perfectly perpendicular to the direction of rotation of the rollers.
In a standard mecanum drive set up if you drive the robot straight forward the rollers on all 4 wheels will slip slightly due to the fact the ground is applying force at a 45 degree angle to their direction of rotation.


Quote:
This is not true if the coefficient of friction of the wheels is different in different directions.
In the case of normal traction wheels commonly used in FRC I think it's pretty safe to say the only difference in traction would be the slight change in the profile of your contacting surfaces depending on the direction of travel. Aside from that the materials on our wheels probably have a pretty uniform friction in every direction assuming the same profile.

I'm not trying to stir up an argument, I'd just like to see something the supports these claims.
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