How To Build a Simple Hovercraft
You should be able to find all the stuff at a big hardware store like Home
Depot, and also at home or by the curb or at a garage sale. If you can't
find a "lift air supply" engine around the house or a garage sale (but you
should be able to) then this project may cost around $100. Otherwise, it
shouldn't be over $40. If you're a good alley picker, you could probably
acheive hoverational glory with $20 or so. It only took me maybe 6 total hours over a few days to make one. I copied and "improved"(IMHO) this
recipe from a Hovercraft
Homepage
Hovercraft Recipe
Ingredients:
--1/2" plywood sheet 4.0' X 4.0'. Hardware stores usually sell a great variety of sheet wood in 8 ft. by 4 ft. sheets. Get the plywood.
--6.0 to 7.0 mil plastic sheet 5.0' X 5.0' It's OK if you don't know what a mil is. It should be like a tarp, but light duty, not the normal kind that's thick & rough with stuff woven in it. If you've ever done indoor painting and covered the carpet with clear plastic, that's what you want. Make sure it's thick enough to be durable, though, especially if you don't have any and so you've got to go out and buy it anyway. As long as it's smooth and flexible and you don't think it will rip too easy, should be fine.
--3/8" diameter carriage bolt 1.0" long
--roll of duct tape
--plastic lid off a coffee can or ice cream gallon-tub, or something similar, to act as a large, flexible washer.
--Lift air supply, which can be:
- Choice 1-- a leaf blower. This is probably the easiest choice
- Choice 2-- powerful vacuum cleaner, like a Shop-Vac, motor-hook up exhuast [the part that the bag's connected to; should be a pipe with air blowing _OUT_
(obviously)]
- Choice 3-- lawnmower-type small engine with a fan (only the
blade assembly, ofcourse, not the whole fan) attached to the
"crankshaft"(the spinning metal rod you see); just try different fans
until one works and enclose it in some kind of duct, like PVC pipe or
actual metal ducting for air ventilation depending on the fan's size. You
will need a ducting/pipe elbow if the engine's crankshaft is horizontal(as on snowblowers) in order to direct the air downward. Avoid that complication and get a vertical-shaft engine(as on lawnmowers). The bigger fan you can scavenge up the better(power!!), but not over a couple feet diameter. Probably the hardest part of this option is that you must either a) get fan blades that fit on the same size axle that the engine has(probably 1/2"), or b) buy a "hub" that fits the crankshaft, drill holes in the hub and fan, and bolt it all together.
- Choice 4-- something else that will blow out air. For instance, I used a centrifugal fan off a broken furnace
--propulsion system (optional)
Instructions
Cut the plywood into a 4.0' diameter circle.
Drill a 3/8" hole in the center of the plywood for the carriage bolt.
Drill a second hole 1 foot from the center of the plywood to fit your lift
air supply nozzle, whatever size that nozzle may be.
Sand all sides and edges of the disk to remove splinters and sharp edges.
Lay plastic sheet on plywood disk and cut about 6 inches larger than the
disk.
Use your plastic lid as a washer and place the bolt through the lid, the
plastic sheet, and the plywood disk (through the center hole) and place a
nut and washer on the other side to secure all the parts together.
Tape the edge of the plastic securely around the outside edge of the
disc. Suggestion: flip the board over so the plastic is on the bottom,
then make sure the plastic is spread out, centered and unwrinkled. You'll
be pleating/ruffling/making-lots-of-little-wrinkles-in the plastic as you
tape to make it even and symetrical. Then staple through the plastic into
the edge of the plywood disc to secure the plastic.
Cut about 6 2" holes in the plastic about 6" from the center of the disk.
These are to allow a small amount of air to escape on which the craft
rides.
Secure the air supply nozzle in the hole you made for it in the plywood
disk.
That is all. How many people can ride the hovercraft will depend on how powerful your lift air supply is.
Now, you can modify this plan greatly. For instance, if you have a big motor and want to make a powerful one, you should probably upgrade beyond plywood! If you want to make a little model hovercraft, adjust everything accordingly. But, this plan does work, and I was quite thrilled when it did, because it is SO EASY! A vacuum cleaner, or that level of motor, I don't recommend, as it won't be enough power to really lift more than 50 lbs. Please e-mail me with any questions or suggestions at [email protected]. Thanks!