DIY - How to Make a Tyvek Flowform Kite

Tuesday, 10 April 2012

I wanted to make a new flow-form kite to replace the one that i lost while doing kite aerial photography (KAP). Also because i saw instructions and it looked a lot easier then the last Rokkaku Kite i made.

A flow-form kite doesn't require any supports. While reading about them i saw that some people made them out of Tyvek, which is a type of plastic houses are wrapped in to act as a vapor barrier.
I checked Lowe's but all they had was their own type of house wrap and it only came in 160' lengths by 10' high and was $100. 

Then on the way home from my sister's, Karrie and i stopped at Menard's. They had several different types and i decided on a soft, non-woven wrap that was only 3' high. It's the $35 one on the left.
NovaWrap



It's actually really strong, i can barely rip it with my hands.

Here's what it looks like up close.
I looked at several patterns online and decided to go with this: The FF03A. It seemed simple, strong and stable. So i copied this drawing into AutoCAD and then traced the lines.
AutoCAD allowed me to get actual dimensions of the material and make patterns.
I ended up changing the dimensions. The original top was 115cm, i first changed it to 52".
Then scaled it down to this size of 24" x 35" for the upper deck.
In my head 24" x 36" seemed a little small for a kite but when i printed out the full size patterns i realized how big it was. I might end up making the larger 36" x 52" kite but first i want to see how this smaller one fly's. It's not like i have a limited amount of Tyvek, it came in a 100' roll.


The upper and lower deck.
The sides and inner ribs.


Here's the top deck cut out.
All of the pieces cut out.

I tested 4 different types of tape. After sticking them i made sure that i really pressed the tape into the Tyvek with the back side of a knife.

The tape in order:

• Gorilla Glue duct tape
• regular 3M duct tape
• clear Tartan packaging tape
• HD clear Duck tape

The Gorilla Glue duct tape didn't stick well and was heavy. The HD clear Duck tape didn't stick well either. The 3M duct tape and Tartan packaging tape worked equally well. But since the Tartan tape was lighter i went with that. Also i think it was the cheapest, about $2.

Taping the fins.

The hardest part was the final upper deck. It was difficult taping the insides all at once.

Here it is with the rigging lines and tails attached.

I finally got to test the kite out. It flew ok. The main problem i had was that i didn't use a swivel clip to attach the line to the kite. That caused the kite to keep rotating clockwise until the bridal lines were completely twisted up.

Here's what the kite looked like as it flew at a low height.

But overall it flew surprisingly well. In high or low winds it was fairly steady. And when i was done it hadn't been damaged at all.

Here it is higher up in the air.

Having built the kite, testing it and seeing how well it flew, i'm definitely not ready to tie my $300 Canon S95 camera to it to try and get some aerial pictures. I think we all remember how that ended up.

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Kite + Camera

Thursday, 10 November 2011

Another use of CHDK that i wanted to try is KAP or Kite Aerial Photography. The simple explanation is just tying a camera to a kite and have it set to take pictures while it's flying. The complicated explanation involves big kites, heavy line, carbon fiber poles and pulleys.

My first attempt was to keep it simple. So when i was at Katie and John's a while back i bought an $8 kite from Harbor Freight. Then while watching the MSU vs UofM game i made a super simple case for the camera out of a bubble-wrap envelope.
The next day john, katie and i tried to fly it but it wasn't even windy enough to get the kite in the air, let alone the kite and the camera.

After reading some more i saw that people use huge kites to lift their cameras. I first thought of a Flow-form kite. Kind of like a para-sail, it doesn't require any struts or poles. I even saw that i could use a balloon.

To lift a pound i would need a helium balloon just bigger than 3 feet in diameter.

But the more i kept reading, the more i heard that the best kite to use for kite photography is the Rokkaku kite. It's supposedly easy to make, easy to fly and very stable. Stability is important because you want the camera to be as steady as possible so the pictures don't come out blurry.

I looked at the plans, it seemed easy enough, so i decided to make the 6 foot rokkaku kite.
Here's the extra strength nylon thread i used.
Here it is after i cut and laid everything out. I still had to sew it all down. I used rip-stop nylon for the material. It's lightweight and strong.
I first sewed the edge and the corner braces.
I screwed up a bit, they all got bunched up at the corners.
The squares turned out ok.
The circles were another story.
Then i punched the hole in the center and strengthened it with thread.
Here's the velcro strap to hold down the struts.
I was able to do 2 before i broke the needle on the sewing machine. Sewing by hand looked even worse. I kept saying to myself, it doesn't matter how it looks as long as it fly's.
But i eventually got everything on there.
For some reason the corners and the strap points didn't exactly line up. I'm still not sure why, but i think it's because i measured all of them from the edge 15 inches but then i folded the corner over 3/4 inch. I guess now i know that the 3 braces in the center should be different from the 2 corners. You can see how the corners don't really line up.
I then had to make the pockets for the fiberglass poles to lock into. They were a pain to make. The top ones have velcro and will fold over.
Here's what they look like when the velcro is attached.
More crooked sewing when trying to sew them to the kite.
Lined up with the pole.
First the pole is slid through then it's folded over and held with velcro.
Here it is locked in.
The string is needed to create the bow in the pole.
I'm not sure if the fiberglass rods i'm using will work, they might be too heavy. They are solid fiberglass and they should be hollow tubes or carbon fiber.
Here's the strings pulled tight to create the bow in the poles. Adjusting the tension causes the kite to fly at different angles.
Also after the practice flight i realized that my reel wasn't going to work. It took too long to wind up all the line on the small spool.
The easiest thing that i saw was a simple piece of wood with handles. Here's the pattern i drew on AutoCAD then printed out on 11"x17" paper.
This is it after i rounded the corners with the router, sanded, stained and waxed.
The last things i had to do was to add a tail for stability and rig the 4 lines that attach to the kite string.


But... before i did that there was a super windy day in November. The wind was gusting up to 30mph. So i thought i could try a small airfoil kite.

I tied on the same bubble-wrap case i made before. It was so windy that the kite was able to lift the camera with no problem.

The wind was so strong that i thought the kite string was about to break. But i left it up around 200 feet for about 15 minutes. The camera was taking pictures every 5 seconds.

Now this is definitely not the way that kite photography is suppose to be done. It was too windy, the kite was too unstable, the camera rig was not level and it was too dark outside. But i just wanted to see how it would turn out.

Here's the typical picture i got. Out of 180 pictures, 95% of them looked like this, blurry and upside down.
Here's why they were so blurry.

But amazingly i got a couple of decent ones. That's me on the football field and my car in the parking lot.
The church parking lot next door.
You can see the kite string in this one.

It was a good learning experience for when i use my homemade kite. I'm going to try it on a day with steady calm winds, sunny sky and a better camera rig. We'll see how that goes.

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