One prototype involved using a basket plate to tilt side to side, directing marbles into two separate hoppers, based on the inputs of a sensor. However, because of the unreliability of the device stemming from the reliance on the accuracy of a motor (where oversteering would dump the marbles out), the design was abandoned in favor of one less likely to suffer from structural issues. 

Another prototype that we designed for our structure was the Angled Jumper. The Angled Jumper uses a sensor to detect the presence of a marble, and uses a rack and pinion to act like a spring, propelling the marble upwards into the next motor-sensor combination. However, difficulties in creating a human interaction element, which would require the entire chain of commands pushing the marble upwards to be cancelled, resulted in the idea being rejected. While a creative concept, it was decided that a traditional elevator was more routed in engineering reality. 

One of the original designs for the mini-sculpture was the create a color sorting mechanism that would sort the balls based on their properties of being light or dark. An NXT light sensor was originally envisioned for the mechanism, which would direct a motor-powered paddle leftwards or rightwards in order to direct a ball into two separate tracks, allowing for an efficient and reliable sorting mechanism. Because there was no dedicated sorting piece, the team decided to try and build the device onto the base of a large, flat collecting plate, as this would allow for space to build and secure the large, Lego-built mechanism. 

While fully autonomous, the Color Sensor would also feature a manual control system, where the user could direct the paddle rightwards of leftward with a series of buttons, thus sorting the marbles based on their own preferences. 

Color Sorting Sensor: Low chance of failure, and failure will only result in the ball being directed onto the wrong path, not ejected from the track itself. 

Tipping Plate: Likely chance of the motor rotating too much due to the inertia of the mechanism, but only a single marble is at risk of being ejected from the mechanism. 

2 Way Ball Drop: Unlikely to fail if built and mounted correctly, but failure will disjoint the mechanism, with a change of breaking / light damage. 

Drawbridge: Requires perfect alignment using a mechanism that is difficult to calibrate, with failure difficult to repair and likely. 

Elevator Bridge: Unlikely to fail due to mounting with the chain, though failure will break the chain entirely. 

Angled Jumper: Likely to fail due to human input requirement, with failure breaking the code and carefully timed jump mechanism. 

Nicknamed the "Death Star" by one of the instructors in our program, the sorting device that our team uses is built to connect to a tube piece and sort marbles based on an input from an NXT motor without requiring the sculpture to be built around it, nor a needing a specialized mounting structure. This allows for easy maintenance, potential improvements on the mechanism, and transfer between different locations on the sculpture, or to a different sculpture if needed. 

Paddle: The base of the design. Rotates and blocks a single path of the track, sorting the marbles in a simple but reliable manner into two hoppers that lie at the end of the track underneath. 

Paddle Shaft: Connects the motor (mounted under the plate) and the paddle (mounted above the plate). Due to concerns over the motor rotating too far and hitting the side of the sculpture, which would damage both the motor and the device, the paddle shaft mounts the paddle on a red technic L3 Pin. As a result, the paddle is able to turn and guide the marble, but a collision with the wall will cause the shaft to turn on it's own without the paddle. In the unlikely event that a marble is caught on the paddle as it turns, the shaft will provide enough "slack" for the marble to move through and continue into the marble separator. 

Marble Separator: Guides the marbles into the correct hopper. Built with angled technic pieces at the end to nudge the marbles into the correct hopper and ensure proper sorting without marbles falling around the hopper. 

Track Adapter: Connects the plate to the technic mechanism, through a series of bars around the plate. This is needed, as there is not compatibility between the technic pieces and the track plate, and the holes cannot fit technic pins, nor are they evenly spaces to run a shaft through. 

Device Connecter: The sole connection needed for a stable intergration of the mechanism into a larger sculpture. Built close the the plate and on a pivot, allowing for easier and more varied integration with track.