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Unread 08-03-2014, 09:56
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Jeffrafa Jeffrafa is offline
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AKA: Jeff Lewis
FRC #1425 (Error Code)
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Join Date: Dec 2003
Rookie Year: 2004
Location: Wilsonville, OR
Posts: 165
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Re: Consistent shooter

Quote:
Originally Posted by Ether View Post


and near the bottom of the list would be a) motor-powered kickers and b) motor-powered wheel shooters.

The sample size for wheeled shooters seems to be pretty small this year. We have a wheeled shooter consisting of 2 8" Colson wheels in a vertical orientation, shooting from fairly low. Each has independent closed-loop pwm control, to make sure the speed is consistent no matter the battery state (on the practice field we are making the same auto shot for a battery just used in a match as a fresh one). Also having the wheels above and below the ball lets us control the amount of back/top spin the ball has (currently tuned for backspin, although the effects of top spin on the ball trajectory are interesting and not quite intuitive - I am fairly confident we could increase our sweet spot range with top spin, but only the longest shot distance would improve. We have only done enough testing to demonstrate the spin effects I calculated, but not enough to justify a change.)

So far in our 1st day of qualifying matches we are 8/10 in auto mode (shooting from behind the white line), and have the 2nd highest cumulative auto score in our district (2nd to a 2-ball auto, but not by a lot). The 2 misses could likely be attributed to human error, as auto wheel speed was being read from an analog knob on the drivers station, now it's a set calibrated value.

Scoring high in teleop has not been as consistent as auto, but I am confident that will improve with more driver practice. We will see how things pan out in day 2 of this district, and at our second district in 2 weeks.
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