How to Build a DIY Marble Run

Learn how to engineer your own gravity-powered marble track using simple items found around your house. HowTo: Family Edition: family how-tos that actually help.

1. Prepare your track pieces. Cut your cardboard tubes in half lengthwise to create open-faced tracks. You can also cut flat pieces of cardboard into rectangles to act as ramps or bridges.
2. Create a starting point. Tape your first tube to a wall, the side of a couch, or a chair. Make sure it is tilted downward so gravity can pull the marble forward.
3. Build your path. Attach more tubes and cardboard pieces below your starting point. Test your marble after every new piece to make sure it keeps rolling.
4. Add obstacles and turns. Try curving your track by taping tubes at angles. You can even add a 'catch box' at the very bottom using a small bowl or a cut-up cereal box.