How to Build a Marble Run from Household Items

Learn how to turn cardboard tubes, boxes, and tape into a custom marble run that tests gravity and physics. HowTo: Family Edition: family how-tos that actually help.

1. Prepare your tracks. Ask a grown-up to help you cut your paper towel rolls in half lengthwise. This creates open 'gutters' that the marble can roll inside of without falling out.
2. Set up your base. Find a wall or a large piece of sturdy cardboard to act as your backboard. Tape your base to the wall or lean it securely against a chair so it doesn't move while you work.
3. Build the course. Start at the top and tape your first cardboard track at a slight downward angle. Place a marble at the top to test if it rolls down. If it works, add another piece of track below it, making sure the marble can transfer from one piece to the next.
4. Add obstacles. Once your basic path is finished, add fun features like 'jump' gaps or tunnels made from uncut tubes. Keep testing with your marble after every change to make sure it still reaches the finish line.