pic: WCD 3 CIM PTO Ball Shifter Render

[asid61]

Originally Posted by GeeTwo

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.

I'm aware that it shifts, however, the acceleration/current may still be too high for safety even if you start from low gear. Probably need to test that to be sure, because I have no idea, honestly. You'd also need to implement autoshifting for that to work.
The weight cost is on the order of a pound or two for a PTO if you go with the WCP PTO (plus whatever you're using for integration into the system). The alternative for endgame mechanisms is to use discrete motors or pneumatics, both of which usually cost more weight for similar outputs although they are easier and faster to integrate. Of course, the last endgame was in 2013, so maybe they're gone for good (and with them most of the use of PTOs).