Bell Tetrahedral Kite

83,694

322

69

About: Emily Fischer is a Brooklyn-based architect and designer. Since moving to New York City a few years ago, her efforts have been invested in developing a professional career as an architect while maintaining c...

Intro: Bell Tetrahedral Kite

Alexander Graham Bell used tetrahedral kites in the early 1900s to disprove the theory that size detrimentally effected a flying machine's ability to get off the ground. This Instructable will show you how to make your own tetrahedral kite using bendable drinking straws and Tyvek. It's similar in its design to other kites shown here, but this kite uses less material and is guaranteed to get off the ground in very little wind.

The kite shown in this Instructable was awarded 2nd place in the 2009 Fly NY kite competition in NYC. Not too shabby for a first attempt at kite design! Visit Haptic Lab for more information about the project.

Step 1: Ingredients

You will need the following items:

1. bendable drinking straws (a pack of 200 works great)
2. craft or floral wire cut into 3" lengths
3. small pliers for bending and cutting ties
4. transparent tape
5. sail material: about 2 yards of tyvek, tissue paper, or mylar
6. craft glue
7. thin wood dowels (4 or 5 total)

This project shouldn't cost you more than $10.

Step 2: Straw Triangles

A tetrahedron is the simplest Platonic solid: a triangle with 4 faces. To build the individual tetrahedral cells that make up the kite, start with three straws. Flatten the long end of each straw and insert it into the short end of another straw. Make a triangle.


Step 3: Making Wings

Unlike other drinking straw "tetras", this kite only needs two straw-triangles per cell. By using less material, your kite will fly better and at lower wind speeds. To make a cell, simply tape two straw-triangles together. Angle the wings slightly as shown, but don't worry about making an exact 105-degree angle: the bend in the corners will flex for you.

Step 4: Making Connections

Make the bottom of the kite first. Connect several tetra cells together by twisting 3" bits of wire. Clip the twisted ends off; you'll get poked later on if you don't. Keep connecting, making a larger triangle out of the small cells. I recommend using 3 or 4 rows as shown.

Step 5: Kite Skeleton

Now that you've made several larger cell groups of 6 or 9 cells each, start making connections 3-dimensionally. The joints at the bottom will have 4- and 8- point connections; keep using the wire to secure the cells together. A wide kite built of at least 4 rows will fly best; if the kite is too narrow, it tends to get a little crazy in the air...

Step 6: Making Sails

Use Tyvek (mailing envelopes work great), tissue paper, mylar, or any lightweight sheet material to make the sails. Start with a sheet roughly 20" x 30" in size. Fold in half four times. Make a template out of poster board or a cereal box, and position it on the folded sail material at the closed outer corner, matching a perfect right angle. Cut the material on the 3 angled sides. Unfolded, you will have 8 individual sails. Make as many sails as you need- Tyvek is dirt-cheap.

Step 7: Attaching Sails

Using a tiny bit of craft glue (Sobo, Elmer's, etc) secure the sails to each cell, folding the material around the bottom taped edge. Though a bit counter-intuitive, the kite flies with the sails oriented like a flock of "V"s. Trim any access sail material for a good, tight fit.

Step 8: Tying the Bridle

Basically, tie your nylon line at points 1/3 the way down on the "bottom" edge or widest section of the kite ("bottom" is the taped edge of the tetrahedral cells). You'll have a bundle of lines- tie them off at a point roughly 1.5 times the width of your kite, making sure there is no slack in the lines. From this tie-off or bridle point, attach the main flying line. Use a figure-8 knot for tying: it's easy and much stronger than a square knot.

Step 9: Flight Test

Your kite should take off in about 10mph winds. It's helpful to have a friend for getting it off the ground- stand about 30-50 feet away from one another, with the kite facing the wind. Once the sails catch the wind, the kite should soar straight up in the air very quickly. It will level off depending on the angle of how you attached the lines.

The kite is collapsible, which makes it a great urban traveler. Right before flying however, attach a few thin wood dowels across the top-most cells with wire- being careful to keep the sails spread into equal widths. The rigidity of the wood along the top is critical: without cross-bracing, your kite will fold up like an accordion and crash to the ground as fast as it went up into the air.

2 People Made This Project!

Recommendations

  • Electronics Tips & Tricks Challenge

    Electronics Tips & Tricks Challenge
  • Plastics Contest

    Plastics Contest
  • Side Dishes Challenge

    Side Dishes Challenge

69 Discussions

0
None
adeptzero

4 years ago on Introduction

i made one by following your instructions on how to do it but i used different materials.. instead of straws, i used broomsticks tied together to make a triangle so it's not collapsible and i only made four triangles.. i spent like less than a dollar not including the kite string.. very cheap but the straw is easier to do..

20131030_164448.jpg20131030_164435.jpg20131030_163616.jpg
3 replies
0
None
flag1aaadeptzero

Reply 4 years ago on Introduction

What are broomsticks? I have searched google and have not found a reasonable answer.

Thank you

0
None
adeptzeroflag1aa

Reply 4 years ago on Introduction

http://1.imimg.com/data/L/H/MY-1485977/coconut-broom-stick_10934440_250x250.jpg

0
None
Zaino23articice

Reply 3 years ago

I am pondering the same question! This is one of the coolest things I've seen in a long time.

0
None
mibzmandombeef

Reply 8 years ago on Introduction

i can't think of a 4 year old who flys kites. and if it was up in the air the 4 year old wouldn't b able 2 drool on it.

0
None
bucklipe

9 years ago on Step 9

One of the pictures I'm looking for is the middle picture on the last step. That shows the edge view from one axis. If we could get the 2 other axis views that would help. Also is the optimum "wing angle" 105 degrees? I found some wing fabric in the paint department of Wal Mart. It is a two layer drop cloth. It is paper on one side with a thin plastic bonded to it. The paper side will facilitate gluing. The plastic side will shed the air smoothly. It is 4X10 feet and costs $3.77. Not bad...

1 reply
0
None
badideasrusbucklipe

Reply 4 years ago on Step 9

sounds good, but it also sounds heavy. i made mine out of a fireblanket from the camping department. the shiny metal blankets. it's actualy a polyester plastic, and paper thin. but it's also sturdy, and hotglue sticks to it like crazy

0
None
badideasrus

4 years ago on Introduction

mrraaaaa! nuuuuu! someone else did it first! dang you pinkdolphi! daaang you! :P

i am literaly building mine right now, out of mylar. lol. yours looks really good though

0
None
Juananz

8 years ago on Step 7

Definitely: shoving a 3D environment into pictures won't help at all in understanding the design, specially if you only upload one of the finished thing. I remark it would be useful if you uploaded many more pictures from the previous step and this one...

1 reply
0
None
BoondockSaintJuananz

Reply 8 years ago on Step 7

It's not that difficult of a design. If you're actually making this, lay your first flat of half pyramids out in a triangle form. If you have a base of four half pyramids then ultimately you will need 10 half pyramids to complete the triangle. After wiring these together at the vertices that are adjacent to one another, you should end up with a "sheet" of half pyramids. Create one more of these "sheets" the same size. Once you have done that, lay one sheet on top of the other such that the upper vertices of the bottom sheet (the ones that are pointing up) are touching the bottom vertices (the ones that are flat or horizontal). You should end up with a top sheet that is slightly staggered to the left or right, but forms a level bottom with the other sheet. Wire the vertices at which the two sheets touch. Repeat as desired. Or, you could just hold your first "sheet" up to the computer screen and orient it to be the same as the photograph... "I remark" that anyone with a bit of spatial awareness and a passing mark in Geometry should be able to figure it out.

0
None
BoondockSaint

8 years ago on Step 6

I'm not sure if shops and groceries over in Europe use plastic bags for their goods (I've heard paper is the standard), but plastic bags make great sail material as well.