How to Make a Self Propelled Balloon Car

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Making a balloon car is a fun craft project and educational science experiment that can be done with kids. This activity can be used to help teach kids how wind energy can be used to propel an object, as well as other principles in physics like momentum, force, friction, and speed.^[1] It's also a great lesson in recycling and how to re-purpose waste items into fun toys. You'll only need a few simple materials: some sort of base, straws, skewers, tape, and a balloon.

1. 1

   Cut a 3 by 6-inch (7.62 by 15.24 centimeter) rectangle out of cardboard. Use a pen and ruler to draw the rectangle first. Cut the rectangle out with a pair of scissors or a craft blade.^[2]

   • You can also use foam core. It is the same thing you use for presentation boards.
   • For a fancy car, paint the cardboard with acrylic paint or cover it with duct tape. Let the paint dry before moving on.

2. 

   2

   Cut two 3-inch (7.62 centimeter) pieces from a straw. Do not include the bendy part of the straw. Use only the smooth, straight part. These will hold the wheels and axles in place.

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3. 

   3

   Tape the straws to the cardboard. Lay the straws across the cardboard widthwise, ½-inch (1.27-centimeter) from each narrow end. Make sure that the straws are straight and parallel to the ends of the cardboard. If they are crooked, your car won't go straight.^[3] Secure the straws to the cardboard with tape.

   • Use sturdy tape, such as duct tape. This way, the straws won't wiggle loose.
   • Make sure that the tape covers the entire length of each straw.

4. 

   4

   Cut two 4-inch (10.16-centimeter) pieces from a wooden skewer. Cut the pointy ends off of the wooden skewer first. Next, cut the wooden skewer down to 4 inches (10.16 centimeters). You will need two such pieces. These will make the axles for your car's wheels.

   • If scissors aren't tough enough for the job, try wire cutters.
   • If you can't find any wooden skewers, use lollipop sticks instead. Make sure that they roll around easily in the straws.

5. 

   5

   Slide the skewers into the straws. You should have about ½ inch (1.27 centimeters) sticking out of each end. The wheels will go onto the skewers next. This will allow the axles to rotate freely inside the straws and allow your car to move.

6. 6

   Make the wheels. Use bottle caps or large coins to trace four circles onto a sheet of cardboard. Cut the circles out using a pair of scissors or a craft blade. Make the circles as even as you can.^[4]

   • You can also use bottle caps instead of cardboard.

7. 

   7

   Attach the wheels to the skewers. Poke a hole in the center of each wheel. Slide the wheels onto the ends of the skewers. Make sure that they don't touch the cardboard, or they may get stuck. If the wheels are loose, place a drop of glue or clay on the end of the skewers. Don't worry, this won't stop the wheels from turning.

   • If you used cardboard or foam core, you should be able to make the holes using a pen, pencil, or a skewer.
   • If you used bottle caps, you will need to punch the hole using a nail and hammer. Ask an adult to help you.

8. 

   8

   Tuck a straw into a balloon and tape it in place. Slide a straw into a balloon by 2 inches (5.08 centimeters). Wrap some tape in a tight spiral around the end of the balloon. Extend the tape over the edge so that it covers part of the straw. Make sure that there are no gaps. You want an airtight seal.^[5]

   • Use regular balloon, not a water balloon, noodle, heart, alien, worm, etc.

9. 

   9

   Tape the straw to the top of your car. Turn the car so that it is standing on its wheels. Place the straw and balloon on top, each facing a narrow end. Make sure that the straw is straight. The balloon should be resting on top of the cardboard and the straw hanging over one of the ends. Tape the straw securely to the cardboard.

   • It's okay if the straw is hanging over the edge of the car. If it is touching the ground, trim it down.
   • Don't let the balloon hang over the edge. If you do, it will bump against the ground and stop your car from moving.^[6]

10. 

    10

    Use the car. Blow some air into the balloon through the straw. Pinch the straw shut so that the air doesn't escape. Place the car on a smooth, flat surface. Let go of the straw and watch the car go!^[7]

    • The straw is the back of the car. The balloon is the front.
    • If the balloon is not holding air, there may be a gap. Wrap some more tape around the end of the balloon.^[8]
    • If the balloon still is not holding any air, it might have a hole in it. Get a new balloon.^[9]

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1. 1

   Get a small juice box. You can also use a small pint-sized milk carton as well. If you want a fancier car, you can paint the juice box with acrylic paint, or cover it with duct tape, fabric, etc.^[10]

   • Make sure that the carton is clean and dry.

2. 

   2

   Cut two straws that are the same width as your juice box. Your juice box will have a front, back, and two side panels. Cut the straws so that they are the same width as the front of back panels.

   • Make sure that you are cutting the smooth part of the straw. Do not include the bendy part.

3. 

   3

   Tape the straws to the front of the box. Set the box down so that the front is facing you. Lay the straws down on top, about ½ inch (1.27 centimeters) away from the top and bottom edges. Secure the straws to the box with a strip of tape. These will hold the axles and wheels in place.

   • Make sure that the straws are straight. If they are crooked, your car won't go straight.
   • Use strong tape, such as duct tape.

4. 

   4

   Cut two skewers down to make the axles. Cut the pointy ends off of the skewers first. Next, cut the skewers down so that they are about 1 inch (2.54 centimeters) wider than your box and straws.

   • If you don't have any skewers, you can use lollipop sticks instead. Make sure that they can slide into the straws easily.

5. 

   5

   Slide the skewers into the straws. You should have about ½ inch (1.27 centimeters) sticking out of each end. You will be mounting the wheels onto the ends of these next.

6. 

   6

   Attach some wheels. Fill four bottle caps with clay or pieces of sponge. Press them onto the skewers. Do not let the clay part touch the straws.^[11] You can also secure them with hot glue instead.

   • If you don't have any bottle caps, you can use buttons instead. You can also cut circles out of cardboard. Make sure that they are all the same size.

7. 

   7

   Tape a balloon over the end of a straw. Slide a straw about 2 inches (5 centimeters) into a balloon. Wrap a piece of tape over the mouth of the balloon. Extend the tape over the end of the balloon and onto the straw. Make sure that there are no gaps.

8. 

   8

   Tape the straw to the juice box. Center the balloon and straw on top of the juice box. Part of the balloon will be hanging over the end of the juice box. Part of the straw will be sticking out over the other end. Make sure that the straw is straight, then place a piece of tape over the straw to hold it in place.

   • Use sturdy tape, such as duct tape.
   • If the straw is too long, cut it down. You want only about 1 to 2 inches (2.54 to 5.08 centimeters) sticking out over the edge of the box.

9. 

   9

   Get your car rolling. Blow into the straw to inflate the balloon. Pinch the straw shut. Place the balloon on a flat, smooth surface. Let the straw go, and watch the car zoom!

   • Blow up the balloon.
   • Don't tie the end; rather, just hold it closed with your hand.
   • When you're ready, let go of the balloon end and watch your car go!

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1. 

   1

   Clean out a plastic bottle. You can use a water bottle or a soda bottle. Remove the cap and peel off the label. Clean the bottle out and let it dry.

   • The best size is a small water bottle.
   • Make sure it's thoroughly rinsed it out and clean, especially if you're using a soda or juice bottle.

2. 

   2

   Cut two pieces of straws the width as your bottle. Measure across the bottom of your bottle. Cut two pieces of straw down to that measurement. Use only the smooth part of the straw, not the bendy. These will hold the axles and wheels.^[12]

3. 

   3

   Tape the straws to the side of the bottle. Tape the first straw about 1 inch (2.54 centimeters) from the bottle. Tape the other straw about 1 inch (2.54 centimeters) below the domed part. Make sure that the straws are straight and parallel to each other. If they are crooked, your car won't go straight.^[13]

   • If your bottle has ribs, use those as a guide.
   • Use strong, sturdy tape, such as duct tape.

4. 

   4

   Cut two skewers down to make the axels. Cut the pointy ends off of the skewers first. Next, cut them down so that they are 1 inch (2.54 centimeters) wider than your bottle. They need to be long enough so that they can slide into the straws and hold the wheels.^[14]

5. 

   5

   Slide the skewers into the straws. You should have about ½ inch (1.27 centimeters) sticking out of each end of each straw. You will be sliding the wheels onto the skewers next.

6. 

   6

   Make some wheels. Get four bottle caps. Draw an X on top of each one to find the center. Use a nail and hammer to punch a hole into the middle of each X.

   • You can also trace four circles onto a sheet of cardboard, then cut them out.
   • You can also use buttons instead of bottle caps. Don't poke holes in them and make sure that they are the same size.^[15]
   • If you're scared to use a nail and hammer, stuff a small piece of sponge into each bottle cap.^[16]

7. 

   7

   Attach the wheels. Slide the wheels over the ends of the skewers. Make sure that the inside of the bottle cap is facing out. Don't press the wheels too close to the bottle, or they will get stuck. If the wheels are too loose, secure them with a drop of glue or clay.^[17]

   • If you are using buttons, simply hot glue them to the end of each skewer.^[18]
   • If you stuffed the inside of the bottle caps with a sponge, simply slide them onto the skewers.^[19]

8. 

   8

   Poke an X-shape on the side of the bottle, just below the dome. Set the "car" down so that it is sitting on top of its wheels. Find a spot on top of the car just below the bottle's dome. Use a craft blade to poke two slits in an X-shape. This will allow you to attach your car's "engine."

9. 

   9

   Tape a balloon over the end of a straw. Tuck a straw about 12 inches (30 centimeters) into a balloon. Wrap a piece of tape around the end of the balloon in a tight spiral. Make sure that the tape goes over the mouth of the balloon and onto the straw. Also, make sure that there are no gaps. You want an airtight seal.

   • Insert the straw bendy-side-first into the balloon.

10. 

    10

    Feed the straw through the bottle. Slide the other end of the straw into the X you just made. Keep pushing the straw through the hole until it comes out of the bottle's mouth. You want about 1 inch (2.54 centimeters) of straw sticking out of the bottle's mouth.^[20] If it is too long, cut it down.

    • The straw should bend naturally at its bendy part inside the bottle.

11. 

    11

    Use the car. Blow some air into the balloon through the straw. Pinch the straw so that the air doesn't come out. Place the car down on a flat, smooth surface. Let go of the straw. Watch the car go, go, go!

    • Fill the balloon by blowing through the straw opening at the end of the bottle.
    • Put your finger over the end of the straw once you're done filling the balloon.
    • When you're ready, let go of the straw and watch the car go.

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Add New Question

• Question

  Which of these methods work the best?

  

  The water bottle one. This is because it has the best aerodynamic shape than the other two. It will also go faster and farther.

• Question

  Why isn't my car moving forward?

  

  Try putting it on slippery surfaces like tiles and use rubber wheels. Avoid making your car too heavy. The lighter it is, the more easily it can move.

• Question

  What type of balloons work the best?

  

  Balloons that hold helium are thicker and can hold more air than ones meant for oxygen. Look for balloons specifically labeled for helium.

• Question

  Which one can without a doubt go 1.5 meters every time?

  

  The 3rd, because it is more aerodynamic in shape and does not weigh a lot, so it can go farther and faster.

• Question

  How do I keep the balloon upright? It keeps touching the ground and stopping the movement of the car.

  

  Make sure it is taped or attached properly and near the top of the car, so that the balloon is not able to touch the ground.

• Question

  How does the balloon rocket work?

  

  It sends the car along the ground with motion. This is called wind power and it helps to propel the car forward.

• Question

  Why do you put the balloon at the back?

  

  If you put it in the front, your car is going to go backward.

• Question

  How much weight can it carry?

  

  It depends on the size of the balloon and the type of motor you use. A smaller balloon or motor will carry less weight.

• Question

  About how long does it take to build the car?

  

  It's up to you and how you decide to build it, but the most it can take is 20 minutes, so 20 minutes or less!!

• Question

  What kind of wheels are the best?

  

  Smart Water bottle caps work great!

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• If this is a group or class project, have the kids measure whose car travels the furthest or fastest. This is a great way to demonstrate the scientific method and develop different hypotheses about how to improve the car.

• It is best to use a round balloon rather than a long skinny one. It will condense the air and give you more force.^[21]

• Lightweight boxes such as a cardboard shoebox will make your car go faster.

• Using bigger wheels will cover more distance.

• You may want to attach a straw at the back of the car. It will act as a type of rudder and help your car stays straight.

• Make your car more aerodynamic (slick and straight so it can cut through air and go faster) by playing around with different materials, wheels, and other design features.^[22]

• Use a bigger balloon for more power and speed. When you let go, it may even fly!

• You can also try using old CDs as wheels.

• You can make tires with the bottle caps.

• Don't put the balloon on the wrong side, because if you do, your car will go backwards.

Thanks for submitting a tip for review!

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• If you're allergic to latex, use latex-free balloons.

• Children should be supervised when they're using sharp scissors and pins.

• Be careful with the sharp pins. Bend them at right angles or into a loop with nose pliers, so that they don't slip out of the straw axles.

• Don't blow too much; you could get light-headed and pass out.

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Things You'll Need

• Cardboard
• Scissors
• Wooden skewers
• Straws
• Balloon
• Tape

• Drink box
• Scissors
• Wooden skewers
• Straws
• Tape
• 4 bottle caps
• Modeling clay, hot glue, etc.

• Water bottle
• Scissors
• Wooden skewers
• Straws
• Bottle caps, buttons, cardboard, etc.
• Balloon
• Tape

About This Article

Article SummaryX

If you want to make a balloon car, use scissors cut a rectangle out of cardboard. Cut 2 pieces of straw a little wider than the cardboard and tape them to the cardboard, then slide 2 pieces of wood into the straws to hold the wheels. Punch a hole in the tops of 4 bottle caps to act as the wheels and slide them onto the wooden sticks. Next, tuck a straw into the mouth of a balloon and tape it in place securely, then tape the straw to the top of the car. Blow some air into the balloon and set the car on the ground so it can roll! If you want to learn how to make the body of your car with a water bottle, keep reading the article!

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How to Make a Self Propelled Balloon Car

Source: https://www.wikihow.com/Make-a-Balloon-Car

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