This is my r/c hovercraft built to a superlight design. I thought it would make a good instructable because theres nothing more fun than trying to keep a homebuilt hovercraft drift under control (as you will see in the video at the end) for this reason i find them incredibly rewarding for the amount of effort put into building them ( which is not very much). This one cost me absolutely nothing as i obtained the broken r/c helicopter off of a friend and i managed to find the polystyrene lying around at home, but anyway, on with the build.
materials needed include:
polystyrene sheet (mine measures 10x180x280mm)
an r/c helicopter (preferably broken but with good electronics)
a plastic supermarket bag
a good crafts knife
and of course (the DIY tool we couldn't live without) a hot glue gun
Step 1: Skirt
The rectangular hole cut into the polystyrene base, which can be seen on the bottom of the hovercraft, is about 80x20mm, this is the duct to allow air to enter the skirt, speaking of which the skirt is simply a large piece of plastic bag with yet another rectangular hole cut into it, the size of this hole is not important, but generally its best to leave 1/3 of the hovercrafts width, worth of skirt round all sides. the skirt is attached to the hovercraft by folding the edges of the plastic sheet over onto the top side of the polystyrene (leaving a bit of slack) and glueing them down.
Step 2: Propellor
The air duct, which also doubles as a mounting for the tiny helicopter motor, is just the corner cut off of a small polystyrene box. However it could also be modelled out of some white card. The distribution of air from the prop is normally 2/3 for thrust and 1/3 for lift.
i used a smaller diameter prop off of a plane for aesthetic reasons only, the larger one from the helicopter would work absolutely fine.
Step 3: Steering
The steering system is unusual for a hovercraft but works surprisingly well. It is simply the tail rotor from the helicopter, mounted on its side to push the rear end of the hovercraft left or right. It is mounted onto the back of the air duct and its wires follow the wiring loom around the side of the air duct towards the circuit board, which lies just forward from the very centre of the hovercraft, for weight distribution.