| Aren Siekmeier |
08-07-2014 12:12 |
Re: The Robonauts 118 - 2014 Video
Quote:
Originally Posted by JohnFogarty
(Post 1392464)
I didn't measure the wheel diameter, and I don't have my CAD workstation in front of me. What was it? Weren't they 4in wheels? That kind of reduction would pull some serious amps if they ever met interference on the field.
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Only if they tried to power through the interference. If speed matters, 5:1 with 3.5-4" wheels is pretty alright, and the acceleration and speed (14-18 ft/s depending on losses, 90% of top speed in just under half a second) are really nice. Breakers are at risk if you sustain less than half free speed at full voltage, but acceleration is quick enough that this only happens if you plow into things. So just don't do that.
I don't have Windows up, so I'm not sure of the exact wheel diameter (or the gear ratio) either, but assuming they used small pinions (11 or 12) and the gear is close to the size of the wheel (it is, from my brief glances before), a single gear stage is certainly fine for the drive, if you're not worried about applying lots of force at low speeds, and instead want to get places. Their omnis helped with this I'm sure.
Edit: For reference, we ran 5.1:1 on 4" wheels for our high gear this year. We only needed low gear when we thought we'd be pushing people, but we honestly would have been better off going around. The high gear had really nice response with 6 CIMs for acceleration. I sort of wish it had been faster, but you have to be careful with the longer acceleration time when you do that. |
