The works like sketch model was used to address several key aspects regarding the functionality of the circular intersections. Since the guests will be arranging the tracks as the gumball is falling down, the design of the intersections must not allow them to be placed such that the tracks on the circular intersections and the wall can be slightly misaligned. In this way, the gumball cannot be intentionally trapped in the beginning, making it easier for guests work to arrange the rest of the tracks. Additionally, rearranging the intersections after the guests leave the room is cruicial for the reset.
Raised intersections
As part of our gameplay guests will arrange the tracks as the gumball is falling down, creating extra chaos and adding to the difficulty. This means that we need to ensure that the tracks on the circular intersections and those on the wall could not be misaligned, trapping the gumball. To address this issue we modeled a child safety cap mechanism on the circular intersections. As you can see from the video below, the intersections is naturally raised above the rest of the tracks on the wall by a spring. There are hooks where the tracks on the wall and the intersection match up, and gaps where they do not. When the circular intersection is compressed and rotated such that the tracks on the circle and the wall match up, the hooks will catch and the circle will stay on the same plane as the rest of the tracks, allowing the gumball to pass through. If it is not rotated to the correct orientation, the intersection will pop back up and the gumball can pass beneath it and to the floor.
Reset
Since the circular intersections are naturally raised, the gumball will always make it to the ground either through a set of correctly places tracks, or beneath the raised intersections. This leaves the task of returing all the circular intersections to a raised position. This can be done by attaching a motor to the back of each intersection, and spinning it until it pops back up. For this sketch model I used a standard DC motor and an Adrunio to accomplish this task. The circular intersection is still very easy to rotate freely by hand, allowing the guests to arrange them as they want while they are in the room. However, as the video below shows, once the guests leave the room (simulated in the video of the model using a push button) the motor spins the circle by a random amount, which would allow the room to return to an unsolved state for the next group of guests.