Start Your Engines Challenge

Start Your Engines!
Build a rubber band powered car

Your egg driver is ready to race! But the driver needs your help to build a car. Can you help out? Unleash your creativity and challenge your friends or family! Who will win the race?

Take a look at Esplora’s video for inspiration and then check the instructions below!

Resources:

These are the resources used in the video. You are free to use any other resources which you can find around the house.

• Egg
• Pencil
• Paint Colours
• Paintbrush
• Scissors or Craft Knife
• Driller
• Hot Glue Gun (can be found at local ironmongeries)
• x 4 CDs
• x 8 Bottle Caps
• Wooden Skewers
• Paper Straws
• Rubber Bands
• Kitchen Cardboard Roll
• Popsicle Sticks

We encourage you to work as a family on this challenge, especially since adult assistance is needed when using tools such as scissors, drillers and hot glue guns.

Step 1: Design
Design your car. Keep in mind that the car is going to be powered by rubber bands. When rubber bands are stretched, they store elastic potential energy. When released, this is transformed into Kinetic Energy (motion), which makes the car move forward.

For this to be possible, all you need is a simple machine with wheels and an axle. These rubber bands can be connected from the front to the rear axle. And the wheels need to be able to turn freely.

Step 2: Create

• Choose an egg – this is going to be your driver.
• Cut out space towards the front of the cardboard roll for the driver.
• Using a ruler, measure out 4 holes on the cardboard roll where your wheels will be – two at the front and two at the back aligned with each other.
• Use a driller to drill the 4 holes
• Pass a straw through the back holes. Leave 1cm of straw on either side. Repeat with the front holes.
• Take the 8 bottle caps and drill a hole through their centre. When drilling, make sure you use a hard surface beneath to avoid damaging your table.
• Glue a bottle cap on either side of a CD. Be as accurate as possible and try and align your drilled holes. You can do so by passing a skewer through the bottle cap->CD->bottle cap and turning your wheel. If it wobbles too much, then the bottle caps are not aligned.
• Repeat this with 3 other CDs. You need to have a total of 4 CDs, with bottle caps on either side.
• Take one of the CDs, place some glue on the drilled hole, pass a skewer through it, and pass it through one of the straws. Attach a second CD to the skewer on the other side of the car and glue it in place. Make sure to leave 1 cm of space between the bottle cap and the straw. The skewer needs to be able to rotate freely inside the straw.
• Repeat with your two front wheels.
• Measure and cut x2 2cm strips of skewers.
• Attach one of each on the BACK side of your car to the skewer, in the space between the bottle cap and the straw. Align them to be parallel with one another. Glue them well in place – this is going to be the mechanism for twisting your rubber band.
• Test your wheels again – are they still able to move freely? Or have you accidentally glued the straw to the skewer?
• For the front part of your car, we’re going to build a small structure. Take 4 popsicle sticks. Glue the first two together in a V shape.
• Then place a rubber band on either side.
• Lock the rubber band within the structure by gluing the 3rd popsicle stick to form a triangle. The rubber bands should be able to move freely WITHIN the triangle.
• Attach a 4th popsicle stick to the middle of the triangle. We’re going to use this to attach it to the front part of the car.
• Turn your car upside down to expose the underside of the car.
• Apply glue on top of the 4th popsicle stick and attach it to the underside of the car. Allow enough drying time.
• Turn your car right-side up.

Step 3: Test

• Now is the time to test your car! Attach the rubber bands from the front around the 2cm pieces of wood at the back. Twist your wheels to twist the skewer, which in turn will twist the rubber band.
• Release! Does your car move forward? If not, check where the problem might be, re-build, and try again.

Step 4: Race

• Paint and personalize your car.
• Place your egg driver inside, and race!

What kind of car did you build?

Share your photos and videos on your social media platforms and tag us @esploramalta