COMPUTER-AIDED MECHANICAL ENGINEERING DESIGN
with William Jewett, Erik Skarin, and EJ Miller
May 2014
Challenged to create a pedal-powered di-wheel, I worked in a team of four to take this project, over the course of five weeks, from initial brainstorming to a final, fully-functional machine. The unusual configuration of the diwheel led to a very specific design problem, namely finding the most efficient way to steer while maintaining power.
To us, the best solution was also the most intensive: designing and fabricating a functioning differential that would allow us to use a simple V-brake to change the relative speed of the wheels. Considering the limitations of the Thayer School machine shop (such as they are, it's a wonderful shop, but without 4- or 5-axis milling machines), we designed a spur gear differential and cut the larger gears in-house.
Following the experience of creating the Dartmouth Formula Racing Car, I was well-prepared for this project, and even had some of the same team members. We enjoyed ourselves welding up the frame and assembling the completed components. For easy assembly, the entire drive axle could drop out entirely. A fiberglass seat and ergonomic handles helped with driveability. A spoiler did absolutely nothing practical but looked great.
Check out coverage of the race here. We took a commanding early lead, lost it, and then gained it back for what turned out to be a thrilling first-place finish.