PLTW VEX Marble Sorter 3.3.1

Me and my partner's design for the Marble Sorter Project in Engineering. Hope it helps.
So basically we used weight to sort the marbles, we first used a trapdoor to separate the metal marble, then we used a "teeter-totter" to separate the wood from the plastic. Not a hard design to build, but it does take a while to fix the small problems, such as the marble not having enough velocity or finding the correct counterweight for the trapdoor.

[pauleves]

I'm trying to figure out how'd you build the trap door and the teeter totter and I need your help on how'd you do it, it would be a pleasure if you would respond back to this comment and give me an idea thanks