[Joe Johnson]

Originally Posted by Justin M.

Hmmm...after some thought I think I just might get two more gearboxes, with a total of 4. The robot design would be for 4WD, so now that I think it would make more sense to have each wheel be powered by it's own independent gearbox/chain geardown. It'll wind up costing us almost double, but worth it. Double the strength and reliability, with the same current requirements as a doubled gearbox.

Back to Autodesk....

This is an age old design choice. In general, I come down on the chain between the wheels camp rather than independently driving each wheel. It boils down to this: When you are pushing against another robot, your front wheels tend to lift and your back wheels tend to get more weight on them. This means that your front wheels are likely slipping and your back wheels are doing most of the pushing. In the independently driven wheels case, only your back motors are doing any useful pushing. This is not why you wanted 4 motor drive! So... whether you buy 2 planetary gearboxes or buy the adaptor to drive 1 planetary gearbox with 2 CIMs, I highly recommend that you consider having chain link all your wheels (and by the way the right number of drive wheels is 6 -- FYI).

Joe J.

P.S. It is my considered opinion that the Banebot 56mm gearbox is sufficiently over designed for 1 CIM motor that it can easily accept the load of 2 CIMs. In fact, I think it be converted to accept 2 CIMs AND a Fisher Price in case you are in the Team 25 Camp (a.k.a. The 3-Motors-Per-Side-Minimum Camp)