How do wheels and axles make things easier to move?
A wheel on an axle turns dragging into rolling. Pushing a box across the floor is hard because it scrapes. Put wheels on an axle and the wheels roll instead — much easier! This idea is over 5,000 years old.
Try Tiny Roller for freeComplete MightyCog booklet collection: 82 PDF booklets for $12.99. Instructions only; individual booklets remain free.
Explore the printable packTry it yourself
Push a beam across the table, then push your Tiny Roller. Which one is easier?
Build it: 6 builds that teach axles & wheels
🚗 Tiny Roller: Your very first rolling car — only 13 pieces! (level 1 of 5, about 5 minutes, 6 steps)- 🌀 Propeller Push Car: Push the car and the propellers on its back spin three times faster than the wheels! (level 1 of 5, about 12 minutes, 8 steps)
- ⭕ Rim Distance Bench: Two unequal wheels share one shaft: equal turns, unequal rim travel. (level 2 of 5, about 15 minutes, 9 steps)
- 🔥 Big-Wheel Dragster: Giant back wheels, tiny front wheels — the same spring pushes this car much further! (level 2 of 5, about 22 minutes, 10 steps)
- 🌀 Flywheel Friction Car: Vroom it on the floor, let go — and it keeps on rolling! (level 2 of 5, about 25 minutes, 5 steps)
- 🚂 Floor Express: A remote-control locomotive with headlights, a chimney and a log wagon. (level 4 of 5, about 40 minutes, 17 steps)
In the classroom
- E1 Push, Pull, Roll (Explorers, Foundation)
- I5 Wheels & Measuring (Inventors, Intermediate)
Common engineering questions
How can I try axles & wheels at home?
Push a beam across the table, then push your Tiny Roller. Which one is easier?
Which builds teach axles & wheels?
6 MightyCog builds teach it: Tiny Roller, Propeller Push Car, Rim Distance Bench, Big-Wheel Dragster and Flywheel Friction Car and more. Start with Tiny Roller: 6 steps, about 5 minutes.