How to Build a Mini Hovercraft!
Project Overview:
Want to own a working mini hovercraft, but don’t know where to start? Let’s make one using an old CD, a balloon, and a bottle cap! This mini hovercraft actually floats on a cushion of air, just like the real vehicles used to glide over ice, land, and sea. It's a fun way to see how air pressure can be used to fight against friction, while being creative! Making it yourself gives you the opportunity to customize it, allows you to experience the process of building it independently, and it saves you money! WARNING: Use a hot glue gun carefully or ask an adult for help with the gluing step since the glue and glue gun tip get very hot!
Materials:
1 Old CD or DVD
1 Pop-Top Cap (the kind on a dish soap or water bottle which can open and close)
1 Balloon
1 Hot Glue Gun and Glue
A Smooth, Flat Surface
Instructions:
Make sure the pop-top cap is in the closed position
Apply a ring of hot glue around the bottom rim of the pop-top cap
Center the cap over the hole in the middle of the CD and press it down firmly, ensuring the seal is airtight
Let the glue sit for a few minutes until it is completely dry
Blow up the balloon fully, then pinch the neck closed without tying it
Stretch the neck of the balloon over the top of the pop-top cap
Open the pop-top cap and set your hovercraft down on the smooth, flat surface
Give it a gentle push and watch it glide smoothly across the table!
Explanation:
Normally, when two surfaces slide against each other, friction slows them down by creating tiny amounts of resistance where the surfaces touch, but your hovercraft solves this problem by using air as a barrier between itself and the table. When you open the pop-top cap, the blown-up balloon releases a stream of air that flows down through the hole in the CD and spreads out underneath it, lifting the whole hovercraft up just slightly so it's no longer directly touching the table. Since air molecules slide past each other far more easily than solid surfaces do, this thin cushion of air dramatically reduces friction, letting your hovercraft glide smoothly with barely any push at all, which is the same basic idea that lets full-sized hovercrafts travel efficiently over land, water, and ice!
