A leader in the "favorite woodworking plans" category, this working marble tower toy is a conversation piece in woodworking. Marbles release about every 2 seconds, cascading down and around a network of troughs, ramps, and over a xylophone. Ringing bells, spinning paddles, and tripping levers, children are captivated by marbles making the fun. Full size patterns and detailed instructions. Finished size: 41" tall, 18" in diameter.