Designing a Faster Mousetrap

It’s race day at the track. After checking their cars one last time, racers gather at the starting line. A camera installed at the finish line awaits photo finishes. Spectators and a television news crew line the course.

The Indy 500? Not quite. This is the Trapster Races, featuring miniature cars designed by students in the School of Art’s Industrial Design program.

Magnus Feil, assistant professor of industrial design, introduced the event several years ago, challenging students in his studio course for juniors to design cars— nicknamed “trapsters”—powered only by mousetrap parts. He drew inspiration from the “Rubber Cup,” a popular German competition started by the renowned designer Richard Sapper, in which the vehicles are powered by rubber bands. “My goal was to initiate something similar but with a twist,” he says.

Each year, Feil tweaks the rules. One year, students had to race their vehicles down a long hallway, with emphasis on endurance. This year the distance was just ten yards, with awards for speed and aesthetic appeal. Feil stipulated that no mousetrap parts be visible.

Although students could use any part of the trap, most used its springs as their power source. “Compared to a battery, mousetrap springs provide a short burst of energy and that’s it,” says Feil. “Through experimentation, the students learn how to best use this energy source. They have to find the sweet spot where the car goes fast but can also can cover the required distance. Small factors, like the diameter of the wheels, can make a huge difference.”

Over four weeks, the students tested several prototypes before committing to a final design. Many incorporated gear systems, spools, or pulleys to harness the springs’ power. “Some were surprisingly sophisticated examples of engineering,” says Feil. “I was really impressed by the diversity of solutions.” 

For mechanically minded students like Luke Springer, the project was fun. “In high school I loved physics, and I think that translated into my final design,” says Springer. For others, it was more of a stretch. “I was unfamiliar with building moving mechanisms, so it was challenging for me to overcome the technical hurdles of this project,” admits Frances Tung.

The students also had to make their trapsters aesthetically appealing. Some, like Tung, aimed for elegant simplicity. Others emulated traditional racecars. Feil recalls one trapster that resembled an “origami stealth bomber” with its use of folded paper, and another that “opened like a butterfly” as it raced.

After weeks of design work, the students finally had the opportunity to test their creations head-to-head on race day. Although everyone was nervous and sleep deprived, there was also a sense of relief, says Tung. “I’m sure all of us would have continued to refine and build new trapsters if there wasn’t a set time limit,” she says.

Two cars raced in each heat, with results displayed on a large screen. And that camera positioned for photofinishes? One race was so close that even the photo couldn’t confirm a winner. “We had those racers do another run,” says Feil.

A KCPQ-TV news crew filming the event heightened the excitement. “I started to stress a little after the very first race, when my car smashed into one of the TV cameras,” recalls Springer. “It broke a wheel and damaged the front end slightly. However it was back on the road after a pit stop for some superglue and a spare tire.”

The winners of the challenge earned boasting rights, along with books on automotive design and the potential for a high grade in the course. After the races were decided, the students continued racing their trapsters along the makeshift track. After long hours spent designing and testing their cars, it was time to have some fun with their creations.

“The project challenged everyone in a different way, and that’s what made it so fun,” says Springer. “Some people were more challenged by the aesthetic part, and some by the mechanics. It helped build skills in many different areas. Plus, the cars were really cool to look at it when it was all done.”

Feil couldn’t agree more. “I’ve been doing this for four years, and while some elements are repetitive, every year I see new ideas that I had never thought about,” he says. “The students continue to surprise me. And I love to be surprised."