DIY- Hovercraft with a CD

A hovercraft is a vehicle that glides over a smooth surface by hovering upon an air cushion.
Hovercraft was invented in 1953 by Sir Christopher Cockerell.

We need:

• a CD, broken, of course,
• glue, super-glue works best,
• milk cap, we used a second cap with a secure valve, from a dishwasher bottle,
• a nail;
• a big balloon, bigger the balloon, bigger the hovercraft trip;
• acrylic paint,
• alcohol.

How to:

1. Clean the CD with soap and alcohol;
2. If you use the milk cap, the red cap in picture, punch it with the nail 3 times, if you are using the other one skip this step;
3. Glue the cap to the CD hole, like the picture, the cap as a small contact surface and it must be fairly glued to the CD, this can be a hard task;
4. Let it dry;
5. Paint the CD if you wish;
6. Let it dry again;
7. Varnish it, and let it dry again;
8. If you are using the milk cap:
1.  Blow the balloon;
2. Twist the tip of the balloon so the air can't escape;
3. Carefully fit the balloon on the cap;
4. Place it on the ground and let go;
9. If you are using the cap with the spot system, like the white one in the picture:

1. Attach the balloon to the cap;
2. Open the valve; be careful you can detach it from CD;
3. Blow the balloon using the bottom hole on CD;
4. Close the valve;
5. Place it on the ground and open the valve;

Using the cap with the valve is easier but will moves with both caps.
 
Why?
Air rushes out of the balloon through the hole to provide an air cushion below the CD. The air is escaping on all sides, and therefore this cushion supports the entire surface of the CD, just like a real hovercraft.

Et Voilá!
Fun fun fun!

Enjoy!