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Unread 21-01-2016, 07:26
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GeeTwo GeeTwo is offline
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AKA: Gus Michel II
FRC #3946 (Tiger Robotics)
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Re: paper: Gear Reduction

Quote:
Originally Posted by ThaddeusMaximus View Post
For this game, my suggestion is somewhere between a reduction of 8 and 10. There's no straightaways to accelerate down.
For 8 inch wheels? That's 18-23fps. Way too fast for the confined field of this game. We're using 8 inch wheels and a 4 CIM drive train. We're using the lowest gearing on a TB-mini (10.9:1) and gearing down another factor of two with chain for a total of about 21.8:1. It's only about 8.5 fps, but we should reach it rather quickly on carpet (with both sides working we'll be traction limited) and have plenty of push to get over the obstacles even if only one wheel can get some bite. If you're not planning to cross the terrain, wall, moat, or wrong side of the ramparts regularly, of if you are going to be really light, gear a bit higher, perhaps 14 or 18 to 1.

Edit:
Quote:
Originally Posted by apm4242 View Post
I thought the highest ratio on a Toughbox Mini was 12.75:1? ]
Quite right, and that's what we're using. Our total gearing on the 8 inch wheels is 25.5:1. We had started with the AM-14U2 (so we could have two in hand at kickoff), and ordered the lower gears for an earlier drive train that had much larger wheels.
I did free speed calculations above using 10.9 from memory, and forgot to adjust. It looks like our total will be about 5.7 fps. We're willing to be that slow as we will be a breach specialist, working towards solid high goal capability. If you're planning to focus on scoring boulders, you'll want to be faster than that to get your cycle time down.
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Last edited by GeeTwo : 21-01-2016 at 15:08.
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