[ChrisH]

In previous years motor modifications have been specifically prohibited. The output shaft of the motor assembly may be modified.

To give an example: We used to get "window" motors. These motors had a worm gear built into the case that then turned still another gear that was the output. It would be legal to modify the output gear by putting a hole in it or otherwise changing it so it could be adapted to drive whatever you were trying to drive.

But changes to the worm gear or the motor itself were not permitted.

As a general rule we modify the motors, including the output shafts, as little as possible. That way if we fry one during a competition we can replace it more easily. It can be really hard to put a keyway into a the shaft of a new motor in the Pits at a Regional. If you absolutely must modify a motor, always buy a spare and modify that one too in the same way, and check to make sure it works as intended. Doing so will save much embarasment at the very least.

Besides the stuff you have spares for never breaks