Has 6 wheeled designs surpased tank treads

[jimfortytwo]

I'm not prepared to say whether or not an increased surface area given the same normal force yields more traction. However, anyone who is arguing that it makes no difference whatsoever has both not actually tried it for themselves, and has not read the whitepaper on the subject.

[Paul Copioli]

jimFortytwo,

Was that aimed at me? If so, then I am ready to put my money where my mouth is. Are you?

-Paul

[Tom Bottiglieri]

I would trust what the UFH Engineer has to say about this.

Thats just me though.

[jimfortytwo]

Originally Posted by Paul Copioli

jimFortytwo,

Was that aimed at me? If so, then I am ready to put my money where my mouth is. Are you?

-Paul

No, I wasn't trying to single you out. Though I imagine you have not yet, in fact, read the white paper in question, and have not done the experiments yourself. Or are you holding out on us?

I suggest reading the whitepaper. Following your challenge, I reread it, and the results still somewhat surprise me. I won't bother summarizing, as it would spoil the surprise.

the paper:
http://www.chiefdelphi.com/forums/sh...threadid=15719

I guess the other part of "putting my money where my mouth is" should be to mention the traction tests I did for my team last year. We were looking at 8" hard rubber tires with an aggressive crosswise tread pattern. I did tests for kinetic friction with 30 pounds and 20 pounds of pressure on the tire. I was working with the risky approximation that in a 4-wheel drive robot each tire sees 30 pounds (30*4 =120), and in a 6-wheel design tires see 20 pounds (20*6 = 120). I can't remember the exact numbers, but my recollection is that I extrapolated a 10-20% benefit in the case of distributed load. Obviously a better procedure is needed to give any meaningful results, however.

I remain convinced that the traction advantage of treads over wheels is so highly dependent on the carpet and material that you can not generalize it. If I can put together materials to do a proper investigation of the subject, I will. Unfortunately we're on winter break, so that might have to wait until January.