Parts and Tools
- An old CD (good condition if possible)
- A round balloon
- Glue (polystyrene cement or super glue) or sticky tape
- Pop up drinks bottle top (sports cap)
This guide shows how to construct a simple balloon hovercraft using an old CD. This item is also listed in our practicals section and it can be constructed as part of a lesson, after school club or as a demonstration piece.
Fig 1: CD and sports cap from a drinks bottle
Fig 1 shows the CD and sports cap from a drinks bottle. If no sports caps can be found, a small plastic funnel works just as well. The advantage of using the sports cap is that it contains a valve that can be closed when desired. This makes attaching the full balloon easier. The CD hovers best if it is free of scratches and pits so a new CD is best. Blank PC CD-ROMs can be purchased very cheaply from many suppliers.
Fig 2: Sports cap attached to the CD
In Fig 2, the sports cap has been attached to the CD. Ensure that the centre of the cap lines up with the centre of the hole in the CD. This can be glued in place using super glue or attached using sticky tape. You need to make sure the join is as air-tight as possible.
Fig 3: Finished hovercraft
Fig 3 shows the finished hovercraft. The balloon is inflated and the neck is stretched over the bottle cap. The cap valve should be closed as the balloon is being attached. Place the CD on a flat, hard surface, open the cap valve and give the hovercraft a slight push. The balloon should deflate, forcing just enough air under the CD to enable it to float just off the ground.
Before attempting any of the construction projects featured on this website, ensure you have, and know how to use, the appropriate tools, components and safety equipment and are competent to undertake the project. These guides are for information only and we hold no responsibility for any accidents, injuries or damage caused by the use or misuse of any equipment, project or information contained within this website. In short - use common sense and stay safe!