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Unread 03-08-2010, 14:47
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Re: Drop-center drivetrains: Why?

Quote:
Originally Posted by JamesCH95 View Post
Perhaps you did not understand that I was referring to a 6wd chassis with two traction wheels in the center and four omni wheels on the corners. In my experience these have been fairly resistant to being spun and do not rock much, if at all; a good compromise in my opinion.

I was not referring to a chassis stiffness analysis, but rather keeping track of CG location for the purposes of reducing rocking while manipulating a game piece. While these are both straight-forward analyses to perform, not every team has a lab full of CAD-capable computers and/or trained operators ready to do them.
I caught that. 6 wheel 4 omni isn't terrible or anything but it is more easily spun and negates a lot of the advantages of a rocking drivetrain. The CG issue, while relevant, really isn't something you need computer precision to analyze. If you don't want to rock with an arm too much, you can adjust the drop a little, put the CG a bit more to one side fore-aft, or even run an 8 wheel drive if your CG is centered. You should be able to get a good enough estimate with just some napkin sketches of where the "heavy stuff" goes. CAD isn't required to figure it out.

Even if you do find you need more precision than "I think it'd be best if we put the battery... here", CG analysis is always beneficial on a competition robot.
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Last edited by Chris is me : 03-08-2010 at 14:49.