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Unread 09-02-2008, 16:36
manderson5192 manderson5192 is offline
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AKA: Matt Anderson
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Re: Help with mecanum wheels

Quote:
Originally Posted by 3dude_2231 View Post
we had the same prob, too.
here's what you should do:

* if your using motors from different years, place them in a logical order,
for example: 2 08s in the front, and 2 07s in the back.

* grease the gears evenly, and don't be cheap =]

* calibrate the Victors

* use wide and even cables between Victors and fuses, just in case

* make sure, and you better be real sure your joystick is calibrated and trimmed
and your code is correct.
My team had the same issue as well. We used one encoder to get RPM data for every PWM value and produced a graph of this data. Using this graph we were able to see which victor/cim pairs were consistently faster and where the respective "true" dead zone of pwm values were for each victor. We immediately saw the dead zone ended up centered at 133, not 127. By shifting all PWMs up by six and limiting PWMs so they wouldn't overflow the max of 254 we were able to get a nearly perfect strafe.

Something you might also consider is using encoders, gear tooth sensors, or the gyro in a PID loop.