Racetrap Mousecar



Released Position: The string is attached to the top of the rod sticking out the back. It was just long enough to release from the gyro before the rod reached full extension to avoid lockup.

This project was really my first design competition ever. If only I had more opportunities to compete… The object was simple. Build a mousetrap powered car to go as far as possible. My team and I came up with several ideas, one of which was a hovercraft, because we wanted as little friction as possible. The final design was more conventional, but still very unconventional.

What we have here is a 3-wheel, very lightweight car. 3 wheels eliminates the need to align 4 wheels, and it will tend to go where the nose is pointed. The back two wheels were for a rubberband glider. They were about the lightest I could find. The real secret though was the front wheel. Since mousetraps don’t have much torque and actuate so fast, there was a problem. It was solved by exploiting rotational inertia.  A gyroscope proved to be the perfect solution. The cage was cut to allow the wheel to touch the ground, and it was wrapped in a rubber band to provide grip. An arm was attached to the mousetrap to increase its length of pull. The gyroscope string was then attached to this arm. Winding the gyroscope cocked the trap until the car was released. It took off like lightning, leaving everyone else in the dust, and was still going half speed when it hit the gym divider wall. No one else even got close. I figured maximum distance later to be 73′. I built a smaller, faster car that could go 107′ for another competition against the seniors, but that competition never took place. 🙁

Car #2: Smaller, Lighter, Faster, Farther…


Cocked and Locked. The arm is fully forward, string is wrapped around gyro axle, and a pin through the gyro spokes locks it until released

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