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Unread 24-01-2010, 13:15
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Madison Madison is offline
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FRC #0488 (Xbot)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1999
Location: Seattle, WA
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Re: FRC488 Driving Over the Bump

Quote:
Originally Posted by squirrel View Post
Thanks for posting this Madison. We tried ours out and had some difficulty getting over the bump. Having "stuff" such as the framework to hold the bumpers and ball kicker mounted up higher seems to make it more difficult, because the CG moves up and the robot wants to sit at a 45 degree angle when rearmost wheel gets to the ramp.

I suggest you give it a try with more weight on the robot, approximating the final CG position.

Quote:
Originally Posted by BHOP View Post
where is the center of gravity location on this bot?

I would be curious to see if changing the CG to one side and going over the bump with that side would prevent the robot from jumping or having the whole front go up in the air.

Thanks for the videos.
We're keeping an eye of the CG and doing everything we can to keep it centered. We've found that if we significantly bias it toward one side, it makes the ride up smoother and the trip down more violent as all of the weight comes swinging down toward the ground. We think it's just nicer to our frame and axles if we keep most of the weight away from the ends that hit the ground.

We should, hopefully, have the rest of the torsion box frame together and attached on Tuesday.

Attached is an image showing the CG of my CAD model. It's missing the electronics, but shows the added weight of the bumpers. The electronics will shift CG fore or aft, but probably won't raise it much at all. Ditto for all of the motors driving the remaining mechanisms.
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