LEGO rubber band cars are a fun but simple machine young children can build for fun and experimentation. After the car is built, it can be used in classrooms to demonstrate simple physics to ages 9 through 14.
Purchase the LEGO motorised rubber band vehicle kit. Check a local hobby shop or online vendor to find this kit.
Assemble the pieces for the body of the car, ensuring that you loop the rubber band around the centre axis. The rubber band must in the exact centre of the car for it to provide the proper amount of suspension. Attach the front axle and pop on the wheels. Make sure they are securely popped into place.
Slide the rear-wheel axle halfway through the back. Before connecting the axle with the other side, slide a gear into the centre of the axle. Attach the axle and secure the rear wheels into place. Test all the wheels on the car to make sure they spin freely. If they get stuck, try removing them and reattaching them. For your car to work, the wheels must move easily.
Draw the rubber band back and attach it to the grooves in the gear. Wind the gear so the rubber band tightens to full capacity. Do not overwind the rubber band because if it breaks you will have to take the car apart to repair it. Lower the car to a smooth surface and let it go. The gear will unwind the rubber band, propelling the car across the surface.
This experiment is useful for teaching students about simple physical science concepts. Different versions of this car may provide different results. Test them against one another. Record and discuss your findings.