Hovercrafts are a great little project for those looking for something a little unusual. This is made out of materials you would find lying round home plus a couple of cheap easy to get electronics if you don't already have them. This hovercraft is capable of going over water, ice, snow, short grass, concrete and other hard surfaces.

Materials

Chilly bin lid (for base)
Plastic bags. (for skirt)
Tape
Hot glue
Balsa wood
Your choice of electronics (two motors with speed controllers and propellers, servo for steering, receiver and transmitter, and battery)
thin plastic or plywood ( for bottom of hovercraft that directs the air to the skirt and rudders)
assorted pieces of wire for control rods.

Tools

Craft knife
Scissors
Hot glue gun

Sorry the video has the writing in the middle, my silly video editor.

Step 1: Base and Skirt

The base is the lid of a polystyrene box that looked about the right size, it had a nice grove around the perimeter that i used to direct the air from inside the hovercraft, out into the surrounding skirt.
A thin layer of plastic was glued around the inside ridge so the air from the fan was directed though the groves cut out to the skirt, it also stopped water filling the skirt when the craft was moving forward.

To construct the Skirt plastic rubbish bags were cut out flat then into 150mm wide strips. Two half pieces of a pvc pipe with a 45 degree angle on the end were used as a template for cutting and taping the corners of the skirt together to get a clean shape, this isn't necessary but is useful. lastly a 20mm by 75mm hole was cut into the bottom plastic panel, this was to let air into the bottom of the hovercraft to make it hover, this could also be done by putting holes in the skirt, but i found this just as effective, and didn't make the skirt at risk to ripping.

Step 2: Steering!

All that is needed to complete the steering is some 5mm dowel, icecream container, hot-glue and two paperclips.

Cut two 140mmX70mm rectangles out of the ice cream container, this will be our rudder fins. Cut a slit about 5mm from the back of the fins about 10mm up from the bottom and bend them up to 90 degrrees so they face each other. Poke a small hole in each of these little tabs you just made and straighten out a paperclip and bend the ends down so that they are 70mm apart. this is to link these two fins together, this will make the rudders move a the same time.

Make a second tab about 45mm from the back edge about 5mm wide on one rudder, this will be connected to the servo.

For the frame cut two pieces of dowel 180mm long and two 50mm long. Poke the two 180mm long parts 70mm apart, 20mm into the polystyrene at the rear of the base then use the small pieces as supports and glue it all in place.

To join the rudder fins onto the frame place three dots of hot glue on the fins equally spaced at the top middle and senter of the hinged side, then press it against the frame and pull in and out about 2mm. This create a thin section of hot glue that will act as a hinge.

Lastly bend the second paper clip so it's straight with one end bent down and one sideways, this will be the link between the rudders and the servo.

Step 3: Eletronics!

The electronics you put on your craft can vary quite a lot, i just had some old brushless motors lying around about 2900kv so not very big but they worked fine. once your motors are installed you may want to add a chamfer around the lift fan to allow a bit more air flow.

List of electronic components i used:

Two Turnigy 1811 2900kv brushless motors with matching propellers and Turnigy 6A plush speed controllers.
Hextronik HXT500 9g servo
Turnigy nano-tech 2 cell 850mAh Li-po battery
Four channel or higher radio transmitter and receiver ( i have a spectrum 5e transmitter with a AR500 receiver)

First glue the lift fan to the plastic bottom in the center of the hole in the base, this may need a little reinforcing with balsa wood to stop the bottom flexing. The thrust fan needs a mount to hold it above the base so it doesn't hit the lift fan or base, this was just a scrape of balsa wood glued into the base the the motor was just glued on the front. The thrust fan can now be mounted, make sure the blades wont touch as both motors spin.

The lift fan speed control was plugged into the throttle channel so it didnt require holding and the thrust fan was controlled by the elevator control and rudder went into the rudder channel.

Try to keep your hovercraft balanced in the center, this makes it rise evenly and hover well on water so keep your battery in the center.

Step 4: Have Fun!

Depending on the power of your thrust motor you should be able to go quiet fast on water and hard surfaces and if you have heaps of power maybe over grass and gravel but gravel and rough concrete tear up the skirt quickly.

I am pleased how this turned out and i was surprised of smoothly it ran. It turns sharp and hovers very well. Next time i would make the skirt out of something more resilient like sail material or even just heavier plastic bags, as on rough concrete and gravel the skirt gets holes quickly.

Here is a short video, sorry for the writing in the middle of the screen, my movie editor put it there.

http://youtu.be/szKAZFXMyKE