This was a "junior design" class project, for which my group and I received $150 to design and fabricate a mechanism to automatically shift bicycle gears based on the speed of the bike. We utilized the existing derailleur and bottle cage mount to make this design generalizable to all bikes, and used an Arduino Micro to control the system. The mount for the mechanism was 3D printed out of PLA.

I initially came up with the idea for the project, and we selected it because of its practicality and feasibility; also because we could add on to it if we had the time. Once we started making prototypes, my first big contribution was moving and redesigning the mount for electronics and the motor to fit the bottle cage mount of our bike. The reasoning behind this was the standard spacing of the screw holes would allow us to attach our prototype easily to our test bike, and to any bike in general. After that, I designed a circuit for all of our electrical components, built breadboard circuits to test our prototypes, and designed a custom PCB to be made by Dr. Trevor Marks, a lecturer and mentor in the Mechanical Engineering Department. Admittedly I broke our first PCB, so I worked with Dr. Marks to redesign it so that all the traces were on just one side of the PCB for simpler soldering. Finally, I designed and made the laser-cut housing for buttons that would go on the handlebars of the bike.

Below are pictures from over the course of the project.