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Unread 23-11-2013, 12:42
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Re: Mecanum Differential Drive

Quote:
Originally Posted by Oblarg View Post
This is false; if you draw a free-body diagram for the rollers in contact with a ground on a Mecanum drive train, you'll see that the effective coefficient of friction compared to a traction wheel of the same material is reduced by sqrt(2)/2, because the friction force on each roller acts parallel to its axis. That is to say, if you apply the same force in the forward/backward direction to a mecanum drive and a traction drive, the induced friction force on the rollers needed to keep the robot stationary is greater on the mecanum drive by a factor of sqrt(2), since the friction force from each roller is pointing at a 45-degree angle (it must, to keep the rollers on opposite sides from spinning).

He was talking about locking the rollers so they can't rotate, in which case traction is equivalent.