A simple moving car

The simple car model is made from a 0.5 litre plastic bottle, 10 cm wooden sticks (axles), 4 plastic caps (wheels), a motor, a battery and a switch. The caps are fixed on the sticks and mounted on the bottle through plastic tubes, which act as bearings for the axles. The motor’s rotation is passed to the rear axle with a pulley and belt: if the small pulley is on the motor and the large pulley on the axle, the wheels turn more slowly but with more force. A seat and steering wheel are made from cardboard and a cap, and an exhaust from a plastic tube, for decoration. Cutting the plastic bottle with a utility knife is a job for the teacher or an adult: the part is held firmly, the blade is never pointed toward you, and gloves are worn; the glue gun and soldering also happen under supervision.