Quote:
Originally Posted by Cal578
In addition to things posted above, consider your gearing ratio. Sideways motion has the highest total torque demand for mecanum drives (due to friction of the rollers). Your gear ratio should be such that the motors run at about half of their free speed, for typical sideways robot speed. That will give you a good range (so you can move sideways slow or fast and still be in the middle of the motor speed-torque curve).
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+1
The torque while strafing is ~1/SQRT(2), (71%) times that of forward driving since the wheels are quite literally driving into/away from each other and the rollers free spin, creating friction from the thrust loads. The
tractive torque in diagonal movement is arguably half that (since only half the motors are running and the other two wheels are dragging). The torque in the forward/reverse directions are the same as traction wheel drive trains with the same coefficient of friction.
For good strafing, the rollers need to be able to free spin as much as possible. Also check that none of the thrust bushings are wearing out on the rollers. Also, clean the rollers. All of this is such a p.i.t.a, it's why we don't do Mecanum any more.