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Unread 30-08-2012, 11:44
Adrian Clark Adrian Clark is offline
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FRC #1678 (Citrus Circuits)
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Re: Ground clearance

Quote:
Originally Posted by stinglikeabee View Post
Additionally, I would suggest against a drop center 6WD layout. Instead, raise the front and place your center of gravity (CG) within the rear 4 wheels. This will allow 4WD maneuverability while having capability of 6WD without the teter-totter effect. The 2012 RoboBees robot "Yow Sting" used a 0.5" raised front and could rotate in place on the back 4 wheels.
How do you think this drivetrain compares against a 6wd drop center in terms of maneuverability?

Typically the "teter-totter effect" isn't detrimental to a robots performance unless the 6wd drop center is poorly constructed or the driver is unnecessarily jerky. When you introduce any more than two wheels on a drivetrain you also introduce turning scrub, where the wheel has to move laterally when the robot turns. To much scrub can be the death of some 4wd bots as when turning the robot has to supply the force to drag the wheel laterally. A large part of the philosophy behind the 6wd drop center is that when you turn the robot does not pivot around either set of four wheels, instead it pivots around the center wheels while "teter-tottering" between the two sets of wheels. This makes it so the robot never fully rests on one set of the four wheels thus making the turning scrub close to non-existent giving you much faster steering and a surprising amount of control.

Last edited by Adrian Clark : 30-08-2012 at 11:46.
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