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Unread 30-01-2013, 21:59
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Re: 375 LBS??

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Originally Posted by theawesome1730 View Post
True, but a robot on wheels (while unpowered of course and parallel to our own wheels) should theoretically have a lower coefficient of friction than the chair? Please correct me if I'm wrong.
Not necessarily. You appear to be using the AM HiGrip Wheel (if I'm not mistaken), and assuming your carpet is standard FRC carpet, the CoF is listed as 1.067. I'd guarantee that roller chair wheels have significantly less grip than that.
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Unread 30-01-2013, 22:03
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Re: 375 LBS??

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Originally Posted by stevend1994 View Post
Not necessarily. You appear to be using the AM HiGrip Wheel (if I'm not mistaken), and assuming your carpet is standard FRC carpet, the CoF is listed as 1.067. I'd guarantee that roller chair wheels have significantly less grip than that.
Thanks for clarifying that for me. Either way, it still has a huge pushing force. Not shown in the video is me sitting on the carpet (which is FRC carpet) and having the robot push me. I only weigh about 150 lbs, but I would assume the coefficient of friction for jeans on carpet is much higher than chair feet
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Last edited by theawesome1730 : 30-01-2013 at 22:04. Reason: spelling fix
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Unread 30-01-2013, 23:20
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Re: 375 LBS??

Im scared, i dont think our team wants to be pushed around
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Unread 31-01-2013, 19:16
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Re: 375 LBS??

Quote:
Originally Posted by theawesome1730 View Post
Thanks for clarifying that for me. Either way, it still has a huge pushing force. Not shown in the video is me sitting on the carpet (which is FRC carpet) and having the robot push me. I only weigh about 150 lbs, but I would assume the coefficient of friction for jeans on carpet is much higher than chair feet
Going through a few different sources on the internet, it looks like the CoF between aluminum and carpet is somewhere between .3 and .7 (loose average). Let's say .5, and that would give you a pushing force of about 180 pounds. Still very formidable. Welcome to any corrections on the CoF I estimated.
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Unread 31-01-2013, 19:31
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Re: 375 LBS??

Nice shooter! Like it. Seems very accurate too! Can't wait to see it at Kansas City!
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Unread 31-01-2013, 19:32
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Re: 375 LBS??

Pushing force is a zero sum game. Unless you've discovered some super material with a CoF greater than 1.3 you can exert no more force than any other robot that weighs the same amount.
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Unread 31-01-2013, 19:40
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Re: 375 LBS??

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Originally Posted by Cory View Post
Pushing force is a zero sum game. Unless you've discovered some super material with a CoF greater than 1.3 you can exert no more force than any other robot that weighs the same amount.
What is the source of the 1.3 number?
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Unread 31-01-2013, 20:11
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Re: 375 LBS??

We were able to drag two people across the floor with a two sim kitbot without a issue. Better step up your game . Beautiful chassis BTW
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Unread 01-02-2013, 01:16
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Re: 375 LBS??

Quote:
Originally Posted by propionate View Post
What is the source of the 1.3 number?
It's commonly accepted that the "best" tread materials used in FRC give a static CoF of around 1.3.
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