Activity: Hovercraft

Nikita with the hovercraft.

On SCOPE's human transport episode, you saw Nikita build a hovercraft. Here’s how she did it. Watch the clip.

What you need

• An old CD that you don't need anymore
• Some craft glue
• A cotton spool
• A balloon
• A peg
• A flat surface, like a table.

What to do

1. Glue the cotton spool onto the CD, making sure the holes line up.
2. Glue a small circle of paper on the top of the cotton spool, and poke a very small hole in it.
3. Allow all the glue to dry.
4. Blow up the balloon, then twist the neck and peg it so no air can escape.
5. Stretch the neck of the balloon over the spool.
6. Place the whole craft on a flat surface and release the peg.

What's happening?

The hovercraft you made won’t go that fast and you can’t ride it, but it works on the same principles as a real hovercraft, riding on a cushion of air.

In reality, hovercrafts can travel over water or land with a giant fan propelling them forward, by blowing air out the back. Some hovercraft can travel up to 130 kilometres per hour! That’s fast!

The air for the model hover craft is going to be coming from the balloon attached to the cotton spool; however, for it to work at its best the air must be released fairly slowly. This is easiest if your cotton spool has a very small hole through it. This should also stop air leaking out elsewhere.

As the air from the balloon escapes, it moves downwards through the hole in the spool. This results in an invisible cushion of air between the CD and the table. This air cushion makes our hovercraft skim easily across the table with practically no friction. But it still has no fan to drive it in a particular direction, so instead you have to give it a push.

The hovercraft is a pretty cool mode of transport; it’s just a shame you can’t go for a ride on this one!