Pushing the Limits of Rubberbands
One of my favorite experiences at Art Center College of Design was a team project to design and race our own performance rubber band-powered vehicles. Our mission was to experiment with materials, body construction methods, weight distributions, and visual designs to create a vehicle that could complete three different race courses all based on the tension-energy of elastic bands.
At the start of this project, our class evaluated rubber band vehicles from previous classes to learn from past mistakes and successes. We benefited immensely from the work of previous students. We saw vehicles that used space frames composed of interlocking tetrahedral pyramids to vehicles that were constructed with tree branches. Some employed four tires, others three. Designs ran the gamut from being exercises in material experimentation to optimizing racing performance.
Approach & Solution
For our team, we challenged ourselves to reduce vehicle weight while improving overall handling. We wanted to build on the past successes through simplification and refinements. To reduce weight, we looked into materials that provided the highest strength-to-weight ratios and aimed to reduce the number of parts needed to construct a vehicle. We turned to carbon fiber rods, joined by SLS parts, ultimately yielding a design that weighed only 530 grams, second lightest in our class.
We also focused our energies on improving suspension and road traction. With only a limited number of winds in our elastic bands, our vehicle would benefit from keeping the rear wheel in contact with the road as much as possible. Therefore, we built a suspension system that applied a downward pressure on the rear wheel, forcing the rear portion of the vehicle to buckle down if the backside ever goes airborne. Lastly, to enhance road traction, we researched various types of rubber compound and decided to mold our own tires.
Our bonefish-inspired racer made a strong showing on race day, outperforming all other vehicles in the drag race. At its top speed, it traveled at 15.5 mph.