1. Key the drive shaft that fits onto the CIM.
Without the keyed shaft the motor will spin no matter how tight the collar is clamped down.
2. Add an encoder to the drive train.
An encoder on the drive motor allows the module to be driven by speed instead of power. There is significant drag in the complicated mechanism so there is also significant variability module to module. Being able to use and SRX with feedback in speed mode greatly improves this situation. Of course having an encoder on the drive side of the module also greatly improves autonomous response both in controlling the modules relative to each other, and in determining drive distance.
We made both of these mods last year and there was a significant improvement in the performance of the modules. It would be great to get this "out of the box."
Thank you for the responses, we are currently looking at the upgrade and will take these things into consideration.