Problem: Build six identical race cars that have an interchangeable battery pack and servo control module. Each car (and driver) completes one lap of the course, returns to the pit and the battery and control module is put into the next car.

Analysis: My adviser’s specialty is kinematic constraints, and I was tasked with designing the interface between the car and the control box. Therefore, I decided to try and have an exactly constrained box with only one degree of freedom (the insertion direction).

Additionally, we observed that driver practice and tire grip were keys to winning.

Solution: Using a sheet metal preloading mechanism, we achieved the required preload for the constraining contact points. Additionally, we practiced a lot as a team and used tape to remove the dust from our tires between heats.

Results: Unfortunately, our preloading force was not as high as the insertion forces used during the excitement of a race. And so sometimes the driver would overpower one of the preloading mechanisms and the control box would jam. Nevertheless, and thanks in great part to driver practice and tire grip, our team won first place in the competition!

The video below is not from our year, but will give you a sense of the race.