This page chronicles this year's (2006) science fair project, which also relates to hovercrafts. After the project is
done with - it's currently being prepped for state science fair - the webpage will be updated with a more detailed walk through
of the whole process and more information on the project, as well as videos. STAY TUNED!
Two of the members of the original group are currently building a completely human powered hovercraft, and are very close
to completion. We will update the site when we are finnished, and we will update people in the Newsletter about our progress.
Check the pictures section if you are interested.
The frame is made of aluminum, and the hull is made os insulation
foam. The skirt is made of waterproof nylon, and is a normal bag skirt. Our lift fan is a 10 inch diameter centrifugal fan
thats hooked up to bicycle cranks via a bicycle freewheel.
Here is a short proceedure of what weve done so far.
1.
We acquired a 10.5 in. x 12 in. centrifugal fan with a diameter of 10 inches.
2. We mounted a bicycle freewheel to the axle of the centrifugal fan. We bought 52 square feet of aluminum square
tubing and channel.
3. We welded some of the Aluminum tubing and channel to form a square frame, with a supporting beam in the middle.
4. We took a bicycle frame and cut off the chain stays using a sawzall, mounted the bracket into the hub, attached
chain rings, attached cranks to the brackets, and attached Look brand pedals.
5. We welded to our frame a trapezoid shape from aluminum tubing and channel with supporting beams and a space for
the centrifugal fan.
6. We mounted the centrifugal fan to the frame using assorted bolts and washers and clear adhesive epoxy.
7. We mounted the bicycle frame, with bracket, chain rings, and cranks, to the frame, using spherical tubing brackets
that we bent appropriately to fit the bicycle frame. For extra support, we added a ¾ inch aluminum square tube from the bike
frame to the shell of the lift fan.
8. We cut and mounted insulation foam with aluminum foil coating to the frame. We then mounted wooden skid blocks
out of 1x1 blocks of wood.
9. Next, we designed the bag skirt, bought the skirt material (waterproof nylon), and sewed the skirt.
10. We designed a seat with proper recline for maximum efficiency. We built the frame out of wood, and by using winged
nuts and bolts we made it adjustable.
11. We attached the skirt to the foam using duct tape and 1x 2 strips of wood trim as clamps.
12. Next we measured and attached the right amount of chain to the chain rings, and freewheel.
13. We attached a bicycle derailer and adjusted it to maintain chain tension.
14. After discovering that the bicycle and the lift fan were not geared at a high enough ratio for human legs to
peddle, and taking into account the very small amount of resistance, we decided to insert another set of gears in between.
15. We acquired another Bicycle frame, cut the chain stays off using a sawzall, and attached a bracket to the hub.
Then we attached 3 chain rings to a crank, and cut off the crank so as not to interfere with the pedaling or to create instability.
16. We then measured the appropriate amount of chain, and attached it to both sets of gears.
17. The chain kept
falling off because of improper tension, so we made the second bike frame adjustable to increase the chain tension.
18. The gear ratio was still not high enough, but it was enough so that when a light person pedaled hard, the hovercraft
lifted.