Balloon (Air) Powered Water Bottle Car – STEM Challenge/ Science Experiment

This project was a little more complicated than some of my others. I first used a Gatorade bottle, and after trying to make the stupid thing work, found it was dragging on the ground and the balloon wasn’t strong enough to make it work. The second attempt was front heavy because the wheels were too far back and the front fell forward. I attempted to balance it by putting some play dough in the back and unfortunately the extra weight made it too heavy for said balloon to push it along the floor. In terms of horse-power, pretty sure my balloon provided about half a baby horse embryo of power. *Grrr*

Third time was the charm! I had balanced wheels and it was light enough to propel forward. Not going to win any races, but a win in my book.

First of all you need a plastic water bottle.


I marked the places for the wheels to go.


Careful the drill doesn’t slip!


You want to have the hole allow for straight passage of an axle, and low to the floor so it doesn’t have the bottle scrap.


I used craft sticks for my axles – make them slightly longer than the bottle width. You don’t want them too wide or the bottle will wobble, but too narrow and the wheels will rub against the side and not move forward. I used a hot glue gun, and large buttons for the wheels. Hold the buttons in place until the glue dries.


The engine is a straw with a balloon over the end attached with a rubber band. I used a paper straw because my plastic ones collapsed and didn’t let air out of the balloon.


I used duct tape to attach my balloon. The balloon end is on the “front” which was the cap end which provided less wind resistance.


My toddler tried to blow up the balloon, but didn’t have enough umph!


All done! Watch the YouTube clip below to see it in action! 🙂

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s