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Originally Posted by GeeTwo
Do you mean 1+1 on each side compared to 2+0, or 2+2 on each side compared to 3+0?
Edit: I'm going to presume the first, as you're discussing a performance drop. I'll get back to you, but I seem to recall that it was a performance hit, but much closer to 2 CIMs than 1 CIM.
Edit2: By assuming a budget of 100A on one side of the drive train, the 2 CIM can deliver 627W at 3365 rpm, the 1+1 494W at 3638 RPM, and a 0+2 can deliver 425W at 3192 rpm. The output power loss is about 21% for 1+1 and 32% for 0+2. A definite hit, but if you're looking to save weight, it's a viable way to do it without dropping all the way to 1 CIM (247W at 1287 rpm).
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I meant the first option 1 CIM + 1 MiniCIM on each gearbox. So if I'm reading right, a 1+1 config would be about 79% of the power of a standard 2 CIM setup? If so, not a bad option depending on the game. In 2015 we went this route on our H-Drive since we didn't need much pushing power and it was all omni wheels anyways.
Quote:
Originally Posted by GeeTwo
The free speeds are only about 10% different, so gearing the same shouldn't be an issue. It's not like you're going to be able to backdrive the CIM at a higher speed than its bushings were designed for, especially after gearbox losses. If you did want to match them even better, you could just use a pinion with one fewer tooth on the mini-CIM.
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Quote:
Originally Posted by Chris is me
Matching free speed exactly isn't nearly as important as is made out to be on Chief, and the motors are designed to be 1:1 drop in replacements for each other without any adjustment in gearing to compensate. The main thing to avoid is one motor forcing the other one to drive faster than its free speed, which doesn't happen (under load, things even out with these motors nicely). Totally fine to do this.
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I'm aware that mechanically it's not critical, I was just curious as to how it affects the efficiency of the overall system. Presumably the MiniCIMs would be working harder since they would be trying to pull the other motors to a higher RPM, but I'm not sure if this would make enough of a difference in motor current to really matter.