A cardboard marble run is the ultimate rainy-day engineering project — part craft, part physics, and endlessly re-buildable. Using a box and the tubes from your recycled pile, kids design a twisting track and then spend ages testing, tweaking, and racing marbles down it.
It teaches gravity, angles, and patience without feeling like a lesson. Here's how to build a marble run from cardboard that actually works.
A safety note
Marbles are a choking hazard for under-3s — supervise closely, or swap in pom-poms or large beads for toddlers.
What you'll need
- A large cardboard box or a big flat piece for the backboard
- Cardboard tubes (toilet-roll, kitchen-roll, wrapping-paper)
- Strong tape, scissors (an adult job), and a marble or two
- Optional: paper cups and small boxes for funnels and catchers
Build it step by step
- Stand the backboard up — the box on its side, or the flat piece leaned against a wall.
- Plan the path from top to bottom; a gentle zigzag flows best.
- Tape tubes and channels at slight downward angles so each one drops into the next.
- Keep the slope gentle — too steep and the marble flies off, too flat and it stalls.
- Add a catcher — a cup or small box at the bottom.
- Test and adjust the angles until the marble runs the whole way.
Level it up
Add cup funnels, a jump gap, a tin at the bottom for a satisfying clang, or two start points for races. It builds naturally on these cardboard box crafts and toilet roll tube crafts.
Built an epic run? Share your design in the comments at ecoxee.com — loops and jumps encouraged.
Keep reading: How to Make Leaf Print and Nature Art, How to Make Paper Bag Puppets, and Musical Instruments You Can Make From Recyclables.
