[Oblarg]

Originally Posted by SeanFitz

The link for the calculator is here. If I'm reading it right, with a VEX 3-CIM ball shifter (yeah, it will be two-speed) with a 3.68 spread and a 24-60 third stage, the total amps at max are 155, but that's with a 1.4 wheel cof. Take a look and see if the calculator looks right.

On another note, what did you guys use for wheels last year? Is there anything you would change?

Playing around with the drive calculator, the numbers look pretty reasonable. It overestimates the max current on our configuration last year by a fair margin, for what it's worth.

We used the KOP wheels - our drive was a modified AM14U. If I were to re-do that drive, I'd have splurged for two-speed transmissions and used wheels with plaction tread. Our experience was not bad, but it was a solid indicator that 6-CIM single speed is not as great an improvement from 4-CIM single speed as one would think, since if you're geared to move reasonably fast you're still limited in pushing ability by the main breaker (in a sense, you're just trading problems with the drive breakers for problems with the main breaker, and the only real gain is acceleration). To really benefit from the improved acceleration of 6CIMs and still be able to push, you really do need a two-speed transmission.

Edit: Upon further playing with the drive calculator, it appears that even for a traction-limited drive it is using the static wheel COF for the "max" numbers which is...well, I hesitate to say that it's wrong because that might be what they intend but if that's what they intend then it's rather misleading because that's not what you're going to see in a pushing match. The numbers appear dead-on if you set the static COF to a realistic dynamic COF.