What is a Mousetrap Powered Car?

A mousetrap powered car is a vehicle that uses a mouse trap for a motor. There are many different ideas but the most common and probably the most successful ideas is to attach a string to the mouse trap and axle or the string pull. In this method one end of a string is attached or tied to the arm on the mousetrap and the other end of the string is wound around an axle. By winding the string around the axle the mouse trap's spring is stretched and now you have your stored energy. As the mousetrap car is released the mouse trap pulls the string off of the axle causing the wheels to turn and off the vehicle goes.

mousetrap car basic propulsion theory

Step #1A string is attached to the mouse trap's lever arm and them attached to the drive axle. Notice that the string has a loop tied at the axle end; this loop is caught by a hook on the axle so that the string is attached to the axle BUT it is allowed to release itself after the pulling force is spent. It is important to have the hook on the axle or the string will simple slip of the axle with out propelling the vehicle. Keep in mind that the hook must be short or it will re-catch the string and cause the car to stop.

Step #2Wind the wheels in the direction opposite to the motion you want the mouse trap car to travel, this will wind the string around the axle. Do not to wind the string loosely or it will snag itself. Do not push on the mousetrap's lever arm during this process, you want the string to be tight and to pull the lever arm over.

Step #3Once the car is released, the string is pulled off the axle it cause the wheels to rotate propelling the vehicle. If the mousetrap is located to close to the drive axle the wheels can spin at the start wasting energy. If the mouse trap is located too far from the drive axle there will not be enough pulling force to propel the racer to the finish. It is important to try the mouse trap in several locations from the drive axle in order to find your racers best performance.