How to Design a Mouse Trap Car

You can turn a regular mousetrap into a car with a few materials

Mousetrap cars are useful little contraptions for teaching physics. The key concepts of potential energy and kinetic energy are effectively illustrated, and mousetrap car makers get to see firsthand this transfer of energy. Mousetrap cars are also good for racing.

Things You'll Need

• 1 wooden mouse trap
• String
• 4 wheels
• 2 axles, (cylindrical rods)
• 4 eye hooks
• 4 rubber washers
• Strong glue

Instructions

1. Attach the four eye hooks to the base of the mousetrap. Align the eye hooks and place two on each of the short edges of the trap.

2. Thread the axles through the eye holes. Be sure there is ample space for the rods to turn. The axles must be parallel to each other and longer than the trap to avoid any problems with friction.
   Place rubber washers on the axles near the eye hooks. This keeps the axle in position. Leave enough space between the washer and the eye hooks to allow movement but not enough to allow any sideways movement when the mousetrap car is moving. Adjust as necessary.

3. Use strong glue to firmly attach the wheels to the axle. The wheels you choose will make a big difference in the performance of the mousetrap car. Smooth wheels that have little traction can benefit from a piece of balloon over them. Experiment with different widths and types of wheels to see how they perform. CD's can replace traditional wheels. Consider putting two CD wheels on the back and smaller wheels on the front.

4. Tie a piece of string to the jaw of the mouse trap. Add a piece of tape or glue it down to be sure it is secure. Leave the other end of the string loose.

5. Lock the trap. Wrap the loose end of the string around the drive axle. This should be wrapped in the opposite direction to the car's intended direction. Now release the trap and test your mousetrap car contraption. Time it and measure the distance it travels.

Tips & Warnings

• Be creative with your car parts. Experiment with different wheels and lighter or heavier materials.

• Mount the mousetrap onto a piece of plywood to make the car bigger.

• Be extra careful with the mousetrap and keep it away from small children.

References

• Kreider Physics Page-Mousetrap Car

Resources

• Doc Fizzix--Mousetrap cars and vehicles