Chaotic Pendulum

Image 1 of 1

This is a K'nex model of a chaotic pendulum we saw at our local science center. The pendulum is a simple double-L design with one end pivoted in the middle and the other end rigidly fixed at a right angle. With just a small twist of the handle at the back of the frame, the freely-rotating yellow endpiece exhibits unpredictable motion. At the other end of the main rotating piece, a counterbalancing arm is rigidly fixed at right angles and provides an off-axis center of gravity. To prevent twisting of the main or secondary arms outside of the plane of rotation, a combination of orange and tan connectors is used to rigidly attach the main arm to the rotating axle. Extra red rods are snapped onto white connectors at the top of the framework for axle stability. A single blue axle spacer is used at the flexible end of the main arm to provide clearance for the free-moving yellow endpiece. This model would produce some pretty interesting trajectories if a light were attached to the yellow endpiece and a time exposure made.