The first stage of the process is isolating one brick at a time out of the unsorted heap. All the mixed-up bricks are poured into the top of the triangular box at the top. The box acts like a bingo cage: when it is spun via the hand-crank on the side, the LEGOs tumble around inside, and fall through the hole one at a time. They fall into the scoop, sized to hold one brick, which drops them onto the slides so the bricks can move on to the next phase. While actual bingo cages are circular, the same shape as the bingo balls, we did not make our box square to match the LEGOs. This is because a square box has right-angle corners that LEGOs can get stuck in, whereas the corners of a triangular box are too small for LEGOs to get into in the first place.
We chose to use a hand crank instead of a motor to drive our isolator to add a fun interactive component to our project. This is similar to the other interactive exhibits that we saw when we went to LEGOLand Discovery Center in Somerville. The entire machine is only four feet tall, putting the crank handle at the perfect height for children to engage with the Lego sorter by winding the crank.
We 3D printed the hand crank and made the roller out of clear acrylic. We chose clear acrylic so that you can see the colorful bricks tumble around inside.
The scoop was also a challenge to design and CAD. THe scoop must attach to the triangular roller but catch the bricks coming out of a hole that is parallel to the ground. The scoop can also only hold 1 brick and dump the rest of the bricks back into the roller if more fall out. To solve this challenge, first we whiteboarded potential shapes to get the angle of the scoop right.
Next we made paper prototypes that we could attach to a cardboard model of the roller.