OPEN KITE (2015)
: open source collapsible tetrahedral kite
© Sehun Oh
All rights reserved
The project brief was about designing a product for play. While I was trying to explore the world of play, I was fascinated by Little Shining Man (Heather & Ivan Morrison, 2011), a huge cube shape kite which consists of hundreds of tetrahedral cells. Originally, Alexander Graham Bell invented this type of kite as a form of airplane about a hundred year ago (Frost King, 1904) and Heather & Ivan Morrison translated Bell's invention into a flying sculpture. I decided to explore this intriguing architectural structure. When I tried to build my early versions of prototypes according to the instructions on the internet, I realised that building tetrahedral kites with drinking straws and tissue papers is quite labour intensive especially when I made it in bigger scale with many cells. So, I tried to simplify the building process and designed several types of 3d printable components with various detail shapes and sizes to test the strength of the structure and also to check the flying ability according to the weight to area ratio.
I have made 10 versions of tetrahedral kites so far. I kept repeating the make-test-improve process each time to understand the relationships among structure strength, weight, size and flying ability so that I could optimise the design. I also tested existing kite products such as a box shape kite and a power kite which can be controlled by 4 lines to understand the virtue of current kiting products. Recently I also changed the component shapes to make the design more suitable for personal desktop 3d printers as an open source project. People can download the component data for free from my homepage, 3d print them and build their own kite. Frost King and Little Shining Man were not made for personal kiting. Frost King was a prototype for an airplane development project. Little Shining Man was built as a sculpture. I think I translated this tetrahedral flying structure into a product for play. I tried to simplify making process by designing specific components. Collapsibility is another major factor that makes it accessible by people. People can build it at home, unfold and bring to the flying location, fold it for kiting and then they can unfold it again to return home and store it under their beds.
HOW TO BUILD YOUR OPEN KITE
Material Preparation (4 cell kite)
3D Printing : 4 pairs of Wing components, 4 gap filler Rings, 2 quick tying Plugs. (You can download the STL files for 3d printing from the link on the right side)
Other materials : 5 drinking straws (4mm diameter, 160~200mm length), Light rip-stop nylon fabric (or thin plastic film), Fishing line (or similar thread), 1.2mm diameter stiff aluminium wire, Thin super glue, Bindig wire for floristry.
Tools : Long nose plier, Cutter.
Download openkite.zip file, unzip it for the Wing, the Ring and the Plug STL files and 3D print them. ABS material is recommended than PLA because it is less brittle according to my experience. I haven't succeeded in printing more than a pair at once for the Wing component, because it was not strong enough when it is printed vertically. If you find some better ways, please let me know.
Left and right side Wing components are the same but one side should be flipped to be assembled together. You can click on the left images to have a closer look.
Tie both wings together temporarily with short biding wires before gluing them with fabric. You have to keep consistency for wing component directions for later assembly. So keep putting the right wing up if you started so.
Glue the tied wings with a piece of light fabric or thin film. Be careful not to use the glue too much, otherwise the 2 wing components will stick together.
Cut the glued fabric from the fabric side to prevent the un-dried glue from permeating down to the table and hindering the making process.
Fabric needs to be cut inside at the corner not to prevent the wing folding and the fishing line penetration.
Connect 2 cells vertically. Cut aluminium wire into short pieces and bend one end to use as folding shafts. Complete connection is made of 6 layers of shaft holes, so use the filler Rings if there are gaps in between the necessary cells.
Hold, bend and trim the other end of the wire with a long nose plier after penetrating the shaft holes.
Connect the centre side wing ends of the side cells together. Also fix the top and bottom of the centre cells with wire shafts.
Next step is making folding structure with thread and straws. At first, tie thread at a wing end hole of a centre cell.
Penetrate the thread through a straw. You can control wing angles with the straw length. If you use 160mm straws, the cells will be a regular tetrahedron. If you use 200mm straws, the wing angle will be 90 degree and you can make cube kite with many cells.
Cut a straw and make 2 pieces of 15mm length plug holders. Penetrate the thread through the other wing end hole, the plug holder and the plug.
This time there are no more holes to go through after a plug, so the other end should be tied at the plug.
Tie a loose bridle from the top to the bottom of the kite. You can adjust the pulling point of the bridle when you fly it.
Ready to Fly
Just go outside and enjoy it! Once you make and fly this basic tetrahedral kite, then you can expand this structure and apply for your own kite design.
If the rear straw braces are not rigid enough when you fly bigger kite in strong wind, you can reinforce by overlapping them with thicker diameter straws. Good luck!
Please use the hashtag #openkite when you post about your versions of OpenKite on the SNS for sharing experience with each other.