Shigley Hauler Competition
First Place Award UC Davis Mechanical Design Class Competition “Shigley Hauler”
Team Members: Michael Zhang, Martin Ward, Dean Levy, Chris Levy, Jarrod Large, Maria Celeste Castillo
Team Name: Electra
Background
This class assignment consisted of designing a gear-box and crate mechanism to pull loads up a 3-foot inclined ramp. More points were awarded to the heavier loads lifted and steeper inclines. In short, the hauler with the fastest completion time for the most trials would win the competition.
Project Description
When designing the hauler, each team worked within the constraints of using only the nylon spur gears and the 2-AA motor provided. Restrictions were placed to prevent teams from enhancing designs by using any stored energy (such as a spring or raising the source voltage from the batteries).
The cart holding the books is pulled by a fishing line that wraps around a spool. My main contribution to our team was creating a Matlab simulation of our system and determining that the radius of the spool which the string wrapped around was an essential dimension that could be optimized for drastically improved performance. The simulation determined the optimal gear ratio and spool radius for each load.
Reflection
The ability to interchange the spools ended up being a key deciding factor in the final performance of the hauler (Figure 4). One challenge in meeting this design feature was creating threaded rods at the optimal theoretical radius. This proved to be an incredibly time-consuming lathe operation, and we opted to utilize the closest matching standard ASTM thread sizes for faster turn-around times (Figures 5 and 6). The video shows run number two, a 30-degree incline with a load of two Shigley Books. The last and most difficult load was a 60-degree incline with 5 books.
We were organized, delegated tasks effectively, and met our deadlines while maintaining a kind and respectful environment. I was so proud of our teamwork and creative design and fabrication solutions.
