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Unread 09-01-2013, 12:37
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thefro526 thefro526 is offline
Mentor for Hire.
AKA: Dustin Benedict
no team (EWCP, MAR, FRC 708)
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Re: Gear Ratio to Maximize Chassis Speed?

Quote:
Originally Posted by Nuttyman54 View Post
I would not recommend this, you will notice a significant decrease in acceleration, and your robot will feel sluggish. In addition, you would have to change your gearing or you would likely not be "traction limited". That is to say, when your robot hits a wall or gets in a pushing match, your wheels will not spin.

You might think this is a good thing, but it means that your motors are stalled and drawing maximum current, which will very quickly blow your drivetrain breakers (and could possibly blow your 120A main breaker).
This, all of this.

There's another thing to think about as well. If you're removing CIMs from your drive train, odds are they're down low in the robot. Do you really want to remove ~5lbs from some area that is less than 12" off the floor? My experience tells me that this is a horrible idea, even if we're only looking at Center of Gravity and ignoring everything Evan said above.

There is a reason that the '4 CIM' drive train has become the standard in FRC. When properly geared, you shouldn't see any issue with brownouts or lessened battery life...

If you're looking for a good resource for doing the calculations that go into designing just about any FRC mechanism, check out this white paper: http://www.chiefdelphi.com/media/papers/2755
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