[Al Skierkiewicz]

JJ,
The simple answer is no. Zener diodes have some specific requirements for implementation. Motor operation is one of the biggest areas of confusion on the robot. While voltage is discussed in terms of motor speed, it is the current that is actually making things happen. A a voltage regulator, the zener diodes would need to dissipate huge amounts of power when the motor is not running. As a hint for your team to consider, the minibot does not meed to stay at the top of the post. It merely must hit the target with enough force to trigger the goal, once is enough. Then it can return to earth. I like that your rookies are thinking. Keep asking, this is one of the more interesting questions so far.