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Unread 20-01-2008, 16:58
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Alan Anderson Alan Anderson is offline
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Re: A New Programmer

Quote:
Originally Posted by paulcd2000 View Post
It happens (to us anyway) because the motor on the right wheel is turned around. The motors don't run the same speeds forwards an backwards, so when the left is running full fwd and the right full bwd, they're in the same direction, but the speeds are off slightly.
The CIM motors don't have significant bias. They'll run the same speed in both directions. If you're reversing the motor direction for the other side of the robot by swapping the wires, the speeds should match well.

However, the Victor speed controllers do appear to have an asymmetric response around the defined neutral value of 127. If you're accounting for the need to reverse the motor direction in code, you'll probably notice this. When we tested things last year, true neutral seemed to be closer to 132.