Skip to content

Hovercrafts - The Perfect Educational Toy

Very small hovercraft such as those made as children's toys are huge fun and have lots of advantages over their bigger cousins. the concept of using air pressure underneath a vehicle as a means of transport was first postulated in 1870, but the materials and engines required to create one were simply not available at that time. Due to these constraints, the first hovercraft appeared as children's toys, which must have helped immensely in their development.

Most people have seen the table game at the seaside where two players stand opposite each other and try to knock a flat plastic disc into the opposing goal. Basically, the disc is an air cushioned vehicle, but it doesn't produce it's own lift. The air pressure that lifts it comes from small holes drilled into the table driven by an electric pump underneath. Hardly a practical means of propulsion for a full size hovercraft, but it does demonstrate the principle very nicely.

Some enterprising kids have even constructed (almost) working one-man ACVs from a simple board and a vacuum cleaner. There isn't quite enough lift to support the vacuum cleaner as well, so a pipe extension is need so that there's a little mobility. I haven't seen one of these, but I'm sure they exist on Youtube. I strikes me that stability would be a major problem though, as there is not design the underneath surface of the board and the skirts are normally very basic. See http://leisure-hovercraft.com

With the advent of molded plastic materials and relatively powerful small DC electric motors, battery powered hovercrafts of a reasonable size started to appear. The real enthusiasts build their own using balsa wood for lightness and two stroke aero engines for lift and forward thrust. These little beauties can reach speeds of 30 to 40 kph and are controlled by radio from a central station with a joy stick for the steering. The great thing about building models is that it's just change of scale to make a working model big enough to ride, and then it gets really exciting!

The dynamics of larger craft are quite different however. Although the principle is the same, larger volumes of air just don't act in the same way. Variations in pressure cause turbulence and this affects the handling of the hovercraft. The bigger types will tend to 'bounce' up and down a little, and also the turbulence will subtly affect the handling. The sheer inertia of a heavier machine means that stops and turns need to be anticipated well in advance, instead of reactng to them as they appear.

Trackbacks

No Trackbacks

Comments

Display comments as Linear | Threaded

No comments

The author does not allow comments to this entry

Add Comment

Form options