[thefro526]

If you wanted to you could put some kind of a passive lift system to hold your arm up. This would be something like surgical tubing, a spring, or closed actuator. Also you can stall the motor by giving it constant power so it doesn't move. Stalling is not good for the motor if it last more than a second or two. The only issue you may encounter with using a worm gear is that when a match is over you may not be able to put the arm down without power.