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Unread 12-11-2012, 15:57
Jared Russell's Avatar
Jared Russell Jared Russell is offline
Taking a year (mostly) off
FRC #0254 (The Cheesy Poofs), FRC #0341 (Miss Daisy)
Team Role: Engineer
 
Join Date: Nov 2002
Rookie Year: 2001
Location: San Francisco, CA
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Re: Super Shifter Gear Ratio's

Depends on the game and your strategy. I have seen robots geared as low as 3fps (a "stump pulling" mode for heavy duty pushing)* and as fast as >20fps (especially for under-weight robots).

Remember that the faster you gear, the more current you will draw while accelerating, pushing, or turning. And the slower you will accelerate to maximum speed.

The slower you gear, the more torque you will have available. But at some point your wheels become the limiting factor (you are "friction limited").

I would guess that most robots with a 2-speed transmission have a low gear in the 4-8 fps range, and a high gear between 10 and 16 fps. Single speed robots tend to be in the 8-12 fps range. But again...depends on the game, depends on your robot, and there are plenty of exceptions to the above generalizations.

Keep in mind that for a given gearbox, you can vary wheel size and chain/belt reductions to achieve a wide variety of actual speeds.

* Definitely the slowest speed I have ever seen was the 2002 Beatty robot, but that's a special case...