The Simple Polymorphic Sled Kite
The Sled Kite is relatively unknown outside of the world of
ardent kite flyers. People who fly kites all the time appreciate the Sled Kite
as a very simple kite to build. It is very forgiving of mistakes in construction
and is a wonderfully easy kite to fly.
Why would anyone call a kite a 'Sled'? Well, when the kite was
invented by William Allison of Dayton, Ohio in 1950, he patented it as a
'polymorphic' kite, meaning it could take on many different shapes according
to the wind. Frank Scott modified Allison's deign and wanted to call it a
'Flexible Flyer'. But that name was already being used by a company making
the Flexible Flyer Snow Sleds. So Scott called his kite a 'Sled Kite'. They
have been called Sled Kites ever since. There are almost as many different
types of Sled Kites as there are people who have made them.
The Sled Kite can be made from almost anything. Trash bags,
plastic store bags, Tyvek™, newspaper, even wrapping paper. Anything
relatively light and strong. The nice thing about Tyvek™ is that it
can be sewn, glued or taped, and it accepts a wide variety of inks and crayons
for decoration. The kite is also easily 'scalable'. It can be made quite
large, or quite small.
On the right, that is the basic plan or outline of the kite.
The black lines are the outline of the kite.
The blue lines indicate units, or scale.
The most common length dowel (stick) from the hardware store is 36" inches.
If we start with a 36" x 1/8" diameter stick, and cut it half, it makes two
sticks for the kite that are 18" long.
That means each blue square in the diagram would be 6". The kite is 18" tall
and 24" wide.
For an 18" tall kite, we would use 1/8" diameter dowels.
If using a 48" dowel, then each stick would be 24"
24" divided by 3 squares means that each square is 8".
If using two fulllength 36" sticks, they should be 1/4" in diameter.
Each blue square in the diagram is now 12" on a side. 

Make a template from posterboard that is half the kite.
Fold the kite material in half and cut both layers at the same time.
This way, when cutting, any errors in cutting will be made exactly the same
on both sides of the kite.
The reason for this is that now lift and drag will exactly the same on both
sides, and the kite won't fly in circles. 

Reinforce the corners 'F' and 'C' with a couple of layers of tape.
2" wide clear packing tape is best for this, but almost any tape will do.
Punch a hole for string at Corner F and Corner C.
Tape the sticks in. One stick goes from Corner A to Corner E. The other goes
from Corner B to Corner D.
Assuming the kite is using 18" sticks and 24" from Corner F to Corner
C:
Cut two strings 40" long. (Distance from F to C, times 3, divided
by 2, plus a little bit for knots.)
Tie one to Corner F and one to Corner C. Check out the
Kinko's Sled page
for detail of this step.
Match the corners of the kite together then tie the strings together with
an Overhand Knot,
so that the knot is exactly in the middle from F to C.
Said another way, the distance, from the knot to F is exactly the same as
the distance from the knot to C.
If the size of the kite is changed, the length of the string between
F & C needs to be 3 times as long as the distance between F &
C.
Too long is better than too short.


Sleds are great flying kites! 

Sled kites on the web:
Basic Sled:
http://www.ex.ac.uk/~jastaple/kites/projects/sled/sled.html 

Written by Gary Engvall 051118 