Quote:
Originally Posted by asid61
I continue to amaze myself with my idiocy. Whoops.
Thank you. 
In any case, you can't accelerate with 6 cims to above 20fps with the roboRIO anyway without a brownout, especially a low voltage, so is it possible to reduce the gearing for that? |
Yes, the gearbox shifts, ball shifters based on the subject line, though the mechanism isn't stated. Low gear is around 7:1 (see first post), so with three CIMs per side, you can easily get up to enough speed for the shift, which can then take you to 20 fps.
Given the voltage brownout levels, I now expect that PTOs are much less useful than they may have been in the past. The first roboRIO year with bumpers, defense, or crazy acceleration requirements will likely be the proof/disproof on this point. The bottim line is that the additional weight for shifting may completely override the weight for separate motors, especially for lower-resource teams.
Added:
Quote:
Originally Posted by R.C.
I'm unsure how PTO's are less useful, as they just power another system. I would say 3 CIM drives will be less useful with the brownouts.
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Yes, and that's why. The reason PTOs have been so useful in the past is that the tightest resource limitation was motor count. This promoted using the same motors for multiple functions. Now, the biggest limitation is the current draw, as in order to keep the motors running, you can't let the voltage drop. Unless the PTO, including the switching hardware and shafts/chains to get the power to where you need it are significantly lighter than the motor and controller, there isn't as much benefit.