[Kevin Sevcik]

I agree that if the system is such that it's going to be difficult or impossible to just pull moon rocks out, then you're in trouble and will likely run afoul of <G36> at some point. The solution doesn't have to be terribly complicated, however. As pointed out above, you could design some slots or spaces into the system to remove balls through. If you don't like the idea of that, the next easiest solution is to design the elevator to be back-drivable. Then you just put a hex or square or something on one of the drive shaft ends so you can attach a crank to it and manually crank the elevator until the balls release. Bonus points if it the crank looks like an old style car starting crank and your designated cranker plays the part of a 1900's motorist.