3 motor drive train

[Swampdude]

From what I can tell (since I've never built a 3 or even a 2 motor transmission) the only thing to gain from a 3 motor transmission would be to push hard at high speed. After seeing the coefficient factor of different wheel types, your going to be hard pressed to keep any wheel/tread from breaking loose with 4 motors. I may be off ( I did some math, but I don't completely trust it ) I think if you took the kit bot setup and also used the highest traction wheels you could find (what's been used in the past anyway, unless you've got some new space age material you need to tell me about) - all 4 cims - 21-28 sprockets - You're still going to be able to break the wheels loose in a pushing match. That's without shifting - plain ole kit gearboxes. So, putting another motor on there... If you wanted to break your tires loose while pushing at 5'/s maybe? OK but why? Usually your just trying to hold some ground, not send an opponent into orbit. Or maybe you want to go 20'/s but you could forget about controlling it. Maybe you'll get close to stall if you increase your weight with a bunch of tetras or using the opponent bots weight to leverage it. Anyhow, like John said - I think most of the hype on 3 motors is just that - hype. Do the math and you'll see. I know of a team that seriously knows what they're doing, and they're considering 1 cim/side , 3 speed NBD's and tank treads.
Although we did modify the kit gearboxes to take the FP motors (and lightened them up), just because we could. They haven't been run with 3 motors yet, but it will be fun just to see how they perform. We aren't planning to use them for our competition bot though. If anyones interested in how to do this it's pretty easy. You need to mill that fat 50 tooth in half. Then you can put a 60 tooth 32 pitch gear on the end of one of the cim shafts. We welded the 14 tooth to the 60 tooth, then key it back on the cim shaft. Then you penetrate the other side of the gearbox for the FP to mate with that 60 tooth. It took us 2 days to do it. Maybe later in the season I'll host a vid of our comp bot pushing the 6 motor practice bot around