At 6-feet tall, the amazing Marble Machine 3 “is powered only by potential energy, a little kinetic energy and gravity. there are no motors, batteries or cranks.” Continue reading to see it in-action.

While this video eventually ends, the device can keep going, sending the marble in a loop from the top to the bottom to the top (to the bottom…) without stop, as long as a single weight is repositioned to reset various components.

[via Gizmodo]