Step 1: Circuits, Current, Voltage, Resistance, and More

Before you create this battery powered car, there are a few things you need to know about electricity including circuits, current, voltage, resistance, and more. First of all, circuits are a path in which electrons from a voltage or current source flow. Current is a flow of electric charge, and current electricity is the form of electricity that exists when charges are able to constantly flow. Voltage is the difference in charge between two points, and electricity will flow from a higher voltage to a lower voltage. Resistance is a material’s tendency to resist the flow of charge (current). Lastly, to make your car work, the electricity needs a path to flow through, which must be an electrical conductor such as copper wire.

Step 2: Materials

The materials you will need to build this car is a piece of cardboard, two double A batteries, a few straws, a DC motor, and Lego rods, wheels, and 2 Lego gears.

Step 3: The Wheels and Axles

To make the wheels and axles, you will need Lego wheels, rods, and straws. They are very simple to make, and all you have to do is put a straw over the rod, and put wheels on either sides of two Lego rods. The straws will allow the wheels to turn even if they're glued to the car.

Step 4: The DC Motor

To make the DC motor run, you will need AA batteries. You will make a circuit by connecting two AA batteries and putting the wires on the motor on each side of the batteries.

Step 5: Making the Wheels Spin

To make your wheels spin, you will need your Lego gears and your fully connected DC motor. The first gear will go on the end part of the DC motor that spins, and the second gear will be on the rod that connects the wheels. This makes it so when the end of the motor spins, so does the gear. This gear will then turn the gear on the rod, causing both of the back wheels to turn and power the car.