Wheely Builders

Hi Builder! Today you will make a little car that rolls. We will learn what wheels and axles do and then build a simple rolling car you can race.

What is a wheel and axle?

A wheel is round and helps things move. An axle is a stick that goes through the wheel. Together the wheel and axle help the car roll instead of sliding. Rolling makes moving easier, like when you use a scooter instead of dragging a box.

What you need

• Cardboard (for the car body)
• 4 bottle caps or 4 round wheels (for wheels)
• 2 wooden skewers or 2 straight sticks (for axles)
• Glue or tape
• Scissors (an adult should help)
• A marker or crayons to decorate
• Optional: straw pieces, clay, or small beads to space wheels

Safety first

• Ask an adult to help with scissors and skewers.
• Be careful with small parts if little brothers or sisters are nearby.

Step-by-step: Make your rolling car

1. Cut a rectangle from cardboard about the size of your hand. This is the car body.
2. Make two small holes near each end of the cardboard (one hole on the left, one on the right). These holes go from side to side so the axle can pass through. Ask an adult to help poke the holes.
3. Put a skewer through the front holes and another skewer through the back holes. The skewers are your axles.
4. Attach a bottle cap to each end of the skewers. If the cap has a hole, push the skewer through and use a bit of tape or clay inside the cap to hold it on. If the cap doesn't fit, glue it to the skewer or use small beads as spacers so the wheel can turn.
5. Make sure the wheels can spin. If they rub the cardboard, move the axle or add a small spacer (like a short straw piece) between the wheel and the car body.
6. Decorate your car with markers, stickers or paper windows.

Try this experiment

• Make a ramp using a book and a board or a piece of cardboard. Put the ramp at a gentle angle.
• Place your car at the top and let it go. How far does it roll?
• Try adding a small toy or a coin to the car. Does it roll farther or shorter? Why do you think that happens?

Simple science words

• Friction: a bit like tiny hands that slow things down. Less friction = wheels roll easier.
• Balance: if the weight is even, the car goes straight. If weight is on one side, it may wobble.
• Axle: the stick that the wheels turn on.

Fun challenges

• Race two cars on the ramp. Which one wins?
• Make one car heavier. Does it go faster or slower?
• Try different wheel sizes. Big wheels or small wheels — which rolls better on a bumpy floor?
• Decorate a theme car: spaceship, animal, or race car!

Great job! Keep building and testing. Every change you make teaches you a little more about how wheels and axles work. Have fun, Wheely Builder!