Wheels and moving parts
Design & Technology · Early Years · The School
Round is not enough
A wheel is round. But round alone does not make it work at all. Glue a round lid flat onto a box. It looks like a wheel. Try to make it spin. It cannot. It is stuck fast, not turning at all, ever.
What an axle does
A wheel needs an axle. An axle is a rod through the middle. The wheel spins around the axle. The axle does not spin with it. That is what lets a wheel turn freely, round and round, every single time.
Testing for spin
Push a skewer through a straw stuck to a box. Push a wheel onto each end of the skewer, loose, not glued. Spin a wheel. Does it turn freely? If yes, you have built a real, working wheel.
Things that roll, things that do not
A toy car with real wheels rolls smoothly along the ground. A box with lids glued on just slides and scrapes instead. Feel the difference when you push each one. Rolling needs a true wheel and axle, working together as a pair.
Build your own mover
Try building a simple moving model. Use a box for the body. Use straws for axles. Use card circles for wheels. Push it. Does it roll well? If not, check whether your wheels can truly spin round. A stuck wheel means it is glued, not resting on its axle.