[JonA]

More details of what BigJ is talking about can be found in this paper about the control strategy used by FRC Team 1675. Basically the output is limited based on the inverse kinematic calculations to allow for maximum speed output of the robot to be the same in all directions with overhead for the yaw rate to be added allowing the same yaw rate control regardless of the heading. These calculations result in the reduction of total overall maximum speed (not using the full range when traveling in the forward/reverse direction) in favor of overall normalization of speed and yaw rate. "Beast Mode" basically allows the driver to override this control decision.

The considerations we have mistaken before include accidentally mounting the mecanum wheels in X and not O configuration and balancing and maintaining the weight/downward force on each of the wheels.

The typical 1675 mecanum setup looks like this:

• Four CIM motors
• Four BaneBot P80 gearboxes
• Four AndyMark 8" Mecanum Wheels

We have also experienced issues with the AndyMark 6" Mecanum wheels (GEN 1 and GEN 2) in that the hubs did not hold up to the impulse loads incurred by 120lb robots in competition. The new AndyMark 6" Mecanum HD wheels should be more than adequate based on the testing document they have published.

We have used two different encoder mounting strategies as sometimes we have used chain and sprockets off of the P80s.

• Vex Quadrature Encoder on an idler sprocket
• Vex Quadrature Encoder (Modified output shaft) or USDigital Encoder
• Considered but did not use the austriamicrosystems magnetic rotary encoder which just requires affixing a magnet to the end of the shaft