Toughbox Torque

[Chris is me]

Originally Posted by theprgramerdude

The trouble is getting to the point where it's traction limited. This could be around 150 to possibly even 200 pounds of tractive force with the right gripping setup. Even with 4 motors, it'll be difficult to get a usable top speed once it's geared down all the way. Furthermore, a second gear with a higher top speed for this would probably create a useless power well, and would have to be tested for optimization (calculus would come into play and simplify things here, but considering that only about 10% of my school takes a beginning calculus course, it's out of the question). Last, the normal two-speed shifters are simply too expensive for us, and would also require pneumatics, something we've began to abhore due to it's weight and volume requirements.

Traction limited with the most common tread material drawing 40 amps of current can get you to about 4-5 fps. Not fast but a reasonable speed for a shifter.

Making a 21 speed drive train with a mechanical reversing secondary gearbox is going to be much, much, harder than fundraising the $800 or so two shifters and extras would cost, for almost zero benefit.