The Rogallo kite, invented by Francis Melvin Rogallo in 1948, is an elegant and simple kite. The kite is a square piece of plastic, with a crease, and completely devoid of any kind of strut of stiffener. The elegance of the kite lead Francis Melvin Rogallo to apply the design to many other aeronautical vehicles: from hang gliders to NASA reentry modules.
Although this kite is beautiful in flight, it really looks like it can't fly. It looks like the kind of thing your four year old would make, and you'd throw out when he wasn't looking. Until it's in flight, it really looks like a droopy piece of arts and crafts experimentation.
If you're careful and precise, the Rogallo kite is easy to make and flies quite well. If you're not, it will be easy to make, but will drop out of the sky like a drunken albatross. Make sure you have and know how to use a ruler, x-acto knife, and an accurate corner. Think twice before cutting. Provided you take this seriously and take your time, you should be fine.
Materials
- 38cm x 38cm square of 0.1 mil mylar
- 2.5cm x 80cm strip of 0.1 mil mylar
- plenty very light flying line for bridles
You should also have
Construction Details
The most important thing for this kite is accuracy. If the kite isn't perfectly square, or if the bridle lines are off, then the kite will twirl out of the sky. Therefore, if you can convince the store to cut the mylar for you, it might be worth the consideration. Usually, they have equipment that makes cutting 90 degree angles very precisely quite easy. Of course, if you think that they don't know what their doing, or if they don't look very confident, you should probably get a slightly larger piece of mylar and do it yourself.
Once you have the plastic in the right dimensions, the next step is to give the mylar a crease. Mylar has "memory," and we want to give it a crease that it won't forget. So very carefully pull one of the corners of the square so that it touches the opposite corner. Think of making paper airplanes in grade school. Carefully flatten the mylar, and put the brown paper bag on top. With the iron on the "synthetics" setting, flatten the crease for a few minutes. Don't bother setting the iron to steam; we want to give the mylar a crease, not humiliate it. Put the folded kite under pressure for a few hours: a heavy book or two, for example.
Now we need to prepare the kite for the bridle. Lay and unfold the kite so that the crease is running away from you. Now put two holes along the far right edge: one 16.5cm away from the far tip, and one 28cm away from the far tip. Put one hole on the near right edge, 16.5cm away from the near corner. Repeat the three holes on the left side so that it is symmetrical to the right side. Finally, cut two holes along the crease: one 15.2cm, and one 33.2cm away from the far corner. Cut a single hole in one end of the long strip of mylar.
If we consider ourselves facing north, the crease should be running north-south, there should be two holes in each of the north-east and north-west sides, one hole in each of the south-east and south-west sides, and two holes along the north-south crease. The far tip translates to the north corner, and the near tip translates to the south corner
Finally, the bridle. Tie the long strip to the two holes near you (or on the south sides). The length of the string should be 25cm on each leg. The four remaining holes that are along the edges (on the north side) are attached to 20cm bridle lines, and the two holes along the crease are attached to 24cm bridle lines. The six lines are knotted together, and a small loop is included to attach to the mail line. Note that these lengths are from knot to knot, and are shorter than the total length of the string. Give at least an extra 6cm for knots, and snip off any excess.
Flying
Before you get all excited, make sure you're not setting yourself up for disappointment. Did you use very light flying line? Is there a light, but steady wind? Is your kite square, or is it a little bit triangular? If everything seems good to go, give it a shot. Remember, this kite is a delicate, sensitive thing. Treat it with patience and care. It may not be as easy to fly as an eddy kite or a delta kite, but once you have the hang of it, it's much more fun. Treat this kite like a beautiful woman: don't play hockey with it, dance with it.
Troubleshooting
If your crease is crooked or if your kite isn't square, you might as well throw it out. If the holes aren't in the right spot, you might as well throw it out. Otherwise, try readjusting the bridle lines. Check the lengths. Are they right? Try adjusting it by a millimetre at a time, and see the effect.
Good luck. If you do try it, please /msg me with your experiences.