Take It Further
If the hovercraft doesn’t slide or spin easily, there are a couple of trouble-shooting steps you can take. Make sure the CD isn’t warped or cracked. If it is, just rebuild the hovercraft with an intact CD. If everything about the CD looks OK, poke larger or more holes into the bottle cap. Also, be sure there’s no air escaping from unauthorized and unsanctioned holes somewhere in the build. It all has to go down from the balloon and then out from under the CD.
The surface over which your hovercraft moves is critical, too. A smooth, hard tabletop or counter is about the only surface this design can traverse. Carpet, sand, grass, gravel, dirt, etc. will stop it cold. If you could mega-power more air downward, you might be able to cross these obstacles and full-sized hovercrafts can do just that. Of course, they push a lot more air than you can get from just one balloon.
By the way, launch your hovercraft without the collar and you’ll find that even thought it’s a simple part, it’s rather important. It helps to keep the balloon vertical and pointing downward. In fact, you could test variations of collar design with the type of balloons you use. Change its diameter and height and discover if there’s an ideal way to set it up.
