In a world where aliens have invaded and destroyed New York City, the iron structures of the skyscrapers are all that is left. Humans have developed this vehicle to climb up the frames and escape from the aliens whose inner magnetism render the iron structures deadly.
Our first prototype explored using sticky or magnetic mecanum wheels attached to a normal rectangular chassis. Mecanum wheels allow a vehicle to move in any direction without turning. There were problems with using mecanum wheels to transition from floor to wall to ceiling and ultimately we decided to go in a different direction.
The second prototype was a triangular prism with magnetic wheels on all three edges so they could snap on to metallic walls. In the end we decided that a triangle shape would be cool, but it would be complicated and would not properly fit our needs.
For our third prototype, we decided on a cube shape with magnetic tank treads, rather than wheels. We chose tank treads because it allowed us to have a larger surface area on the wall at one time. This design would also potentially be able to go across ceilings.
The first model of our tank treads were good and steady, but had a few minor imperfections, such as friction between treads, and were not magnetic.
The second design fixed the friction issues and allowed the treads to hold magnets. This model, though, made the frames too thin around the magnets, so they broke often.
Our third and final tank tread design made the frame around the magnet thicker. The result was a tank tread that both looked better and worked better. We 3-D printed all the tank treads and laser cut all the frames for the magnets. After producing all the small parts on a large scale, we glued them together with epoxy.
After the motors and treads were assembled on the cube, we realized that the design was unable to hold itself up on the wall. Because of this, the design was changed entirely for functional reasons to the flat design you see now. While it is not as interesting of a shape, the new design increases the surface area of the treads on the wall and spreads out the weight, so it can effectively climb up the wall.