Octagon Kite

This is a description of the first build of an Octagon Kite. The ultimate goal is to make a Carousel Kite for the town on West Haven, CT. The image I was shown depicted a hexagonal box kite that had a separate center section. An octagon is closer to being a circle and closer to an actual Carousel in configuration. Add to that the fact that I have never made an Octagon Box, and the gauntlet was tossed.

Design: First there are the basics. Essentially, the kite is a ring of fabric on each end and a frame in the middle. I have a lot of 4-foot sticks in stock, so 4 feet will be the basic design dimension. How wide should the rings be? Traditional box kites are often made in thirds, with the top and bottom third of the kite being sail, and the middle third being open. But on this kite, the idea is that the rings on each end of the kite will represent the top and bottom of the carousel, so we do not want them too wide. About a foot wide is good.

Structure: There are structural components that are important in what kiters call the sails, the fabric rings on each end of the kite. We will need pockets to hold the sticks in place. A simple pocket is cut 3 inches long, and 1 inch folded over to form a pocket. A sleeve or pocket for a stick needs to be sewn wide enough to fit the stick, but not too wide, which would allow the stick to slide around. A good guideline is to sew a pocket or sleeve for a stick that is twice as wide as the diameter of the stick. We are using 3/16" sticks. So we need a 3/8" wide sleeve in the pocket to accept the stick. The distance from the needle of the sewing machine to the edge of its Presser Foot is 3/8". If we cut panels for the Pockets that are 3" long, and 1-1/8" wide, the edge of the Presser Foot can be used as a sewing guide, and there will be a 3/8" sleeve for the stick. We have 8 Longerons (sticks that go the length of the kite) multiplied by two end each, we need 16 pockets.It is a good idea to have a sleeve for the longeron on both ends of each sail, so we cut 16 sleeves, 2" by 1-1/8"

Box Kites with individual sails have a problem. The sails like to slip back and forth on the Longerons. The easiest way to fix that is to sew loops on the sails at the Longerons and tie a string between them. We will make Tab Stock from 1" strips of ripstop nylon folded in thirds. We will cut this in to 2" strips so we have 16 loops.

Math. There is always math. We know we want to make the rings, or the ends, a foot wide. How long should they be if we are using 48" sticks? Don't ask me, I have no clue. Math was always my worst subject in school. When all else fails, draw it and measure it. In the process of drawing out an octagon, I discovered that an octagon is the result of drawing two squares and rotating one of them 45 degrees. If 6" squares are used, that makes the apothem 3". Each side of the octagon is 2.5". Now we can use the Pythagorean to figure out the the 'spokes' are 3.25".



Trigonometry? We don' need no steenkin'  Trig.Now we can just scale up those dimensions to the kite we want to make. The spokes in the drawing are 6.5" We want to use 48" sticks. 48/6.5= 7.3846. 7.3846 times 2.5" in the drawing yields a Kite Side of 18.46" 18.46" per side, times 8 sides, is 147.69". We need 2 sails, so we need 295.38" of fabric.

How big is our yard? That is not a trick question. Yes, everyone knows that a yard is 3 feet or 36 inches. But a yard of fabric is 36" deep and as wide as the machine that wove the fabric. Back when dinosaurs roamed and I started sewing kites, the standard yard of kite fabric was 41" wide. Nowadays, 60" wide is the industry standard.

So - we need 295.38 inches of panels and we have 60" fabric.295.38 divided by 60 = 4.92. Yippee! We cut 5 strips of fabric and we have our sails...

And, then again, there is the real world. The fabric that is available is only 58" wide. Back to the calculator... 295.38 divided by 58 is - stink! - 5.092! Now we need a hair more than 5 panels.

Nope. Use 5 panels, get a slightly smaller kite, and cut the sticks shorter.

We want our sails to be 12" wide when we are finished, and we will turn and sew a 1/2" hem on each side, so we need to cut our panels 13" to get a finished sail of 12" For those keeping score at home, 5 times 13 is 65, divided by 36 is 1.8 yards of fabric.

We cut five strips from the roll of fabric. Each strip is 13" by 58". Cut one of them in half to be 13" by 29". Now sew the 2 strips and the half strip together end to end to form a continuous ring. For seamstresses and kitemakers reading this, use the edge of the Presser Foot as a sewing guide, and flat fell and top sew the seams.

The picture above shows an end of the kite sail a ring of fabric, and using a quilting ruler to mark for a 1/2" hem.

A half inch for the hem, and mark the entire 145" of that edge. Then turn it around and do it again on the other edge. Ripstop has an interesting character. It holds a crease really well. Folks who are used to working with 'normal' fabrics would expect to iron a fold for a hem to keep it in place for sewing. Not with ripstop. Fold it, crease it, run it through the machine.

The picture above shows two things. First, along the bottom edge of the fabric, a completed hem. Second, the sail is being creased at intervals to show where the sticks will go. It is simple. Lay it out flat, and crease each end. Then align those two creases in the middle, and crease the ends again, Now the sail is marked in quarters. Now do it again in between those creases, and the sail is marked at even intervals all the way around.

The black things are 5-pound dive weights. They are great at holding fabric in place for creasing, marking, cutting, tacking...

I did a slightly different treatment of the raw edge that will be towards the middle of the kite. It is a great technique that is seen on NPW (Nasa Power Wing) kites. First, we have our tabs, or loops. Kite makers are always striving for accuracy and consistency. This is a great way to have all the loops the same length after they are sewn to the kite.

Above, shows tab stock that is flat, then one that is folded, then a blue one that has a white square on it. The white square is a product called 'Seamstick'. It is double-sided mylar tape. The wooden apparatus is a home made Seamstick dispenser. Bottom left shows a loop on place and a strip of 1" ripstop over it.

 The picture above shows that the ends of the loop are aligned with the raw edge of the fabric. The 1" wide strip is sewn down over the loop and along the entire edge of the sail.

The picture above shows the strip sewn in place with the Loops underneath it. Now we crease the snot out of it. Seriously.

You can't have too much money, too many clamps, or too many sewing weights. Okay. The strip gets folded and creased. Then the flap of the seam gets folded and creased. Then the strip is folded over the raw edge of the seam and creased.

Above is what we are going for. We get a double-folded hem with loops mysteriously sticking out of it. Notice the crease in the fabric opposite the loop. That is one of  our alignment lines for sewing in all the pockets.

I wish I had taken more detailed pictures of sewing in the pockets, but there comes a point where you just want to get the kite done.

Below, the kite is arranged for first assembly. 3/16" diameter dowels, 48" long, were used for everything. The quick and dirty solution for joining the Spreaders to the Longerons is vinyl tubing. It is 3/16" ID tubing cut to 1-1/2" long, with a cross-wise 3/16" hole punched about 1/4" in from the end for the Longeron to go through. 5/16" holes were cut in the sail to allow the vinyl tubing to protrude through.

The pic above does not show it, but along each Longeron is a piece of string. It is tied through the loops in the top, or windward, sail using an Overhand Loop. It was then brought through the loop on the bottom sail. The bottom knots are Overhand Loops that meet the standing line in a Prussik. Whaddya mean, that can't done? If you stay on my good side, I might show you...

Hey, not too bad for a first attempt.

Before we go any farther, this kite, or at least the final kite, will get another octagonal sail in the center. The apothem on this kite is about 22", so start thinking about a 20" (40" Spreaders) octagonal unit for the center...

Prototype for Carousel Kite, 4 feet by 4 feet.

HEY! If it doesn't fly, it's not a kite!

The first flight was very impressive. It rode the gusts and tolerated the wind shifts extremely well. It is a little under-built, a little too flexible. That is an easy fix. Notice that the flying string attaches at a single point. Think about it. Literally, just tie a string to it, and it flys!





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