The Solarbotics Marble Machine Kit - Battery Edition

The battery powered edition of the Marble Machine kit has splendid electromechanical appeal, delivering 8 steel balls down a laser-cut wood frame. Securely tucked under the return rail, the battery pack provides hours of power to rotate the gear wheel that brings the marbles up to the top of the spiral.

If you don't want to get batteries, you might consider getting the solar powered version instead.
Features and Specifications:

• No-solder battery-powered construction.
• Precision laser-cut fibreboard frame.
• All electronic and structure parts included.
• 2 x AAA batteries required (not included)
• Basic tools required (no soldering)
• Est. 1 hour build time