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Unread 08-07-2014, 15:34
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kk052 kk052 is offline
CAD extraordinaire
AKA: kyle lundquist
FRC #2517 (the green wrenches)
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Join Date: Feb 2013
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Location: washington
Posts: 42
kk052 can only hope to improve
Re: pic: New serve mk.1-2517

Quote:
Originally Posted by CENTURION View Post
Doesn't look like anyone has mentioned this yet, so I will. You're going to have a lot of trouble turning this module.

If I understand correctly, both wheels are locked together? When you try to rotate the module while the robot is stationary, one wheel needs to spin one way, and the other needs to spin the opposite, because the center of rotation is between them. And when the robot is moving, and you attempt to rotate the module, one wheel will have to turn faster than the other.

What you need is some sort of differential, so that when turning, the wheels are able to rotate independently, but you can still apply drive power to both.

Here's a great old video that wonderfully explains how differentials work (at least in the context of cars)
it was argued about in the design process about the use of a diff, we decided not to to save space and make the unit simpler, and the less things to go wrong the better, also if there are any ramps in the 2015 game and one side of the wheel gets on it, all the power will be given to the other wheel. we are going to have to use a lower ratio to turn it however
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FRC TEAM 2517 The Green Wrenches
2012 Autodesk Oregon regional
Chairman's award, Entrepreneurship award, Pit safety award
2013 central Washington regional
Imagery award, Pit safety award
2014 we won something but i forgot

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