How to Build a Homemade Marble Run

Learn how to engineer your own gravity-powered marble run using recycled materials and basic physics. HowTo: Family Edition: family how-tos that actually help.

1. Prepare your track pieces. Cut your cardboard tubes in half lengthwise to create open U-shaped tracks. If you are using cardboard scraps, fold them into long strips or V-shapes to create ramps.
2. Create the starting point. Find a high spot, like the back of a chair or a table, and tape your first track piece there. Make sure it is tilted downward so gravity can pull the marble forward.
3. Build your path. Tape your remaining track pieces to a wall or a cardboard base, overlapping them like stairs. Test your marble after adding each piece to make sure it doesn't fall off the side.
4. Add obstacles and turns. Experiment by adding cardboard flaps to make the marble bounce, or create a spiral turn using a curved piece of cardstock.