[Al Skierkiewicz]

<R02> ROBOT parts shall not be made from hazardous materials, be unsafe, or cause an unsafe condition. Items specifically prohibited from use on the ROBOT include (but are not limited to):

And the various rules in several sections that speak to damaging the playing field, floors, etc.

As unlikely as you think it might be, robot parts break, robots tip over, and other people are always present. Liquid gasses in any form pose such a hazard. Liquid coolants of any type cannot satisfy the above rules for safety and preventing damage to field or venue.

While teams will go to any length to try and cool motors between matches, any external method does little to remove the internal heat stored in the motor. The path for conduction of the heat in the armature is only through the two end bearings and brush assembly or from direct radiation to the case and magnet structure of the motor. Teams that use freeze spray, run the risk of the material used in making the spray cold, flushing lubricants from exposed motor bearings. Extremely cold surfaces will also condense humidity out of the air like on the outside of a cold drink. Use freeze spray with caution.