B'zar 2011 Std
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For some people kite building is an art. The Gone With The Wind forum has many regular guests that know how to build a superb kite. One of those goes by the nickname Sugarbaker and has made a B'zar 2011. He was so kind to take pictures of his efforts and told the readers about "how and what" he did. Here's the essence of his postings:
The making of a 2011 Std:
Bzar 2011 build thread - started on: April 10, 2011, 11:26 AM
I thought I might start a thread documenting the build of the recently released (today!) B'zar 2011. Throughout the process, I will add pictures and descriptions of the steps taken to complete the kite... including mistakes and corrections. Hopefully an enjoyable thread to follow, but may take a while to complete. For the first entry, here are pics of the plans and my chosen color scheme.
It's hard to see at the posted resolution, but note the seam overlaps for the spine and both seams running laterally away from the spine... these have tapered/non-uniform overlapping edges creating a billow in the sail once completed. This is unique to this kite and one of the major additions to the 2011 model... should be an interesting trick to prep and sew, but we'll cross that bridge when we get there.
Note that the individual halves will NOT lay flat when sewn together. As I mentioned in my first post, there is a billow in the sail that will cause a concave curve (concave to the flyer) when aloft. In the sail layout file, the solid lines of each panel is where you should be laying them out and sewing. The dotted lines represent where the panels would overlap if each individual panel were laying flat. I hope this makes some things more clear.
While we're waiting for me to cut material for the B'zar 2011 build, I will post some pics from my 2010 version build. I will offer some brief description for each picture and some explanation of technique. Please also note that the B'zar 2011 (and 2010) are not great choices for a first time build. Kites with curved seams and complex panel designs should be reserved for those that have already made the mistakes of their first kite build. This thread is intended more as a documentation of my own build process, and may serve as a loose guide to building your own kite. That being said, please feel free to email any specific questions that I do not address in the body of the thread.
Below is a picture showing why there are marks in the middle of the panel templates... their purpose is to indicate the direction of the bias. This is considered by the designer for aesthetics, but more importantly to minimize stretch in certain areas such as the leading and trailing edges. Take care when cutting your own panels to line up the bias with the templates so as to match the designer's plans, but also to ensure symmetry between halves.
Remembering that these pics are from a build of the 2010 B'zar, technique remains the same. When cutting Mylar material that will go on each half of the kite, it should be cut so that the bias, and texture of the material will be symmetrical (if you are as OCD as I am). Mylar is smooth on one side and rough on the other, so when you cut mylar panels, cut one... then turn the fabric over and cut the other so that the texture will be identical from one half to the other.
So lets assume templates have been cut... out of wood or poster-board, whatever your choice of template is. Now is the time to start cutting ripstop. This is a little late, but I should mention that your choice of color layout can mean an easy or difficult time when you prep your sail to be sewn. This will be relevant soon in this build and I wanted to point out that the color layout I've chosen will be difficult due to the asymmetrical halves.
When sewing a sail, panels will overlap. Dark colors should be laid up towards the front of the kite... in front of light colors. As we only have a full size layout for the right half, when you get ready to lay up the left side some logical thinking will mean we have to reverse this mentality so that when opened up the rule will still hold true... dark colors in front of light colors. To make sense of the posts coming up I'm going to give a pic with panels labeled alphabetically; left and right (see pic).
Ok... now that I've made it confusing, I'll throw out a quick recommendation. Have I mentioned that this should not be the first kite you build? And if you're diving into this kite as a second attempt I would consider making a symmetrical color layout to avoid confusion with the previous rules about colors. If you think it's confusing to reverse your seam overlaps, it's going to be more confusing when I explain that because of my checkerboard type color scheme, a single seam could have varying overlap... and that we'll set up the seams that don't affect the billow of the sail before we attach those that do affect the billow; If you're not confused yet, keep on reading.
My next post will be about hot cutting. I'll have some pictures, but it's hard to take a picture of yourself hot cutting... and frankly I don't want to risk burning myself. I will however direct you to this youtube video that is a great demonstration of efficient hot cutting of ripstop (during the construction of C. Derefat's vortex I believe).You tube video
When you are setting up to hot cut, make sure you have a surface that is safe to use... glass, metal or utility wood surface (wood will burn during this process, so don't use your mother's dining room table). I use a metal table top.
When laying out your fabric, it is important to avoid any wrinkles; lay it out as flat as you can. Polyester is quite prone to static buildup, and this actually helps it "stick" to the surface and keep it flat. You shouldn't have any trouble at all when preparing to cut. See pics... first one is what to avoid, second one is what you want when prepping to cut. (take note of the soldering iron at the top of these pics. I know it looks like the wire is laying on the tip of the iron, but it isn't. The iron isn't even on, as this is a fire hazard. You should only have the iron on when you are going to use it)
Now, remember those lines on the template that I mentioned were for properly orienting the bias of the material? you want to lay your templates out prior to cutting and make a plan in your head for how you get the most out of your fabric when the templates are lined up properly... first pic is hard to make out (pic earlier in thread of 2010 B'zar may give better idea of fabric bias) but it represents how the fabric should line up with the template. Second pic is multiple pieces layout out prior to cutting so as to minimize waste.
Ok... now we're ready to cut.
I'm taking a little break from the sail documentation to show and tell you a little about the frame and parts that will come after the sail is complete. The picture below is a collection of the fittings you'll need to put the frame together. (note that these are my choice of fittings and not the only options).
from left to right:
1. R-Sky center T, 6x7 (We'll talk about this more later).
2. Vinyl endcaps (for spars and LE/Center T fitting stops, stay tuned)
3. HQ end nocks, to fit 6mm carbon ferrule.
4. APA standoff connector (actually to be used at base of spine for this project).
5. I believe these are Jaco standoff-spreader connector... many (probably most) use APA standoff connectors, but I prefer these as they are slightly less bulky.
6. APA leading edge connector (I use size CA).
7. Jaco 3mm standoff to sail connectors (with 'O' ring). I have not used the screw-to-sail style common on R-Sky kites, but may in the future. If these Jaco parts are good enough for Ken McNeil, Jon Trennepohl, Paul Shirey and others, they're good enough for me.
next picture is my frame of choice (and mostly what is recommended by Werner at the B'zar website), from top to bottom:
1. Solid 6.1mm carbon rod for making Ferrules (not shown in previous pic).
2. Pultruded 6.1mm carbon rod (hollow) for upper spreader.
3. 3mm solid carbon for standoffs (1x48" rod should get you through the build)
4. Skyshark p300 for the spine. Werner recommends P2x, but I'm unable to get them right now so I went with the stronger P300 over a standard P200
5. Skyshark Nitro Strong (gold label) Black Diamond. You'll need 2. These rods cost as much as $20 (I believe Steve sells for $18), so measure twice and cut once when we get to that section of the build!
6. Skyshark P200 for leading edges. 4 needed for this kite.
7. Skyshark P100. This is slightly sacrificial to the build, as you will only need approximately 4 inches of this rod (2x2inches) to shim the lower spreaders to accept a 6mm ferrule. The other option is to drill out your center T and use one 5 inch piece...
One last pic for this. I purchased some excellent leading edge material from Paul Shirey when he sold off his supply of kite material... The material is Mylar coated Taffeta ribbon. It is basically 2" dacron tape but coated with mylar on one side. I've seen it on Paul's kites and on some of Lam Hoac's kites from a few years ago. My understanding is that it is not available anymore... or at least very difficult to find. I purchased 40 yards from Paul, and this will be my first time using it in a build.
At this point, I've finished cutting the sail panels, and am ready to secure my seams for sewing. Besides the fabric and a full size plan mounted to a hard board, you should have something to attach the panels to one another. My preference is an inexpensive Elmer's glue stick (I use the kind that is purple... but dries clear). I have used seam tape in the past and find that for curved seams it is difficult to place without creating wrinkles. In addition to wrinkled seams, I find that sewing through the seam tape causes my machine to get gummed up and work less efficiently (with the occasional broken thread). Additionally, I use blue masking tape (generic, purchased from local hardware store) to hold the panels to the plan while glueing. Before laying out the fabric, I tear off approximately 15-20 pieces of tape and stick them to my jeans or other clothes items. This make them slightly less sticky for easy removal from the plan paper and fabric.
For reference, I'll include a previously included image of the sail plan with panels labeled...
The sail should be glued in stages... right half, then left tends to be my natural progression, but more importantly is how you glue the individual halves. Starting with the right half, I place panels B, F, E, I and J on the plan. Static keeps the panels in place for the most part, but I also use tape to hold them. You'll notice that these panels are connected at seams that do not affect the billow of the sail... no dashed lines at connecting points yet. Alignment is critical at this during these steps. All the seams are important, but the most critical are the edges that form the leading, trailing and spine edges. secondly (and equally as important are the edges that will connect to the billowed portion of the sail. Be sure to glue the darkest colors on top of the lighter colors for this half of the sail. Place enough glue to stick, but try not to have clumps, as they could cause wrinkles later while sewing. Get plenty of glue coverage... the entire width of the seam if possible.
This close up image below shows the level of precision needed when laying out your sail; even 1 mm could alter the character of the sail when framed up (and symmetry is very important, so be accurate from one half to the other.)
Next, place and glue panels C and G. This seam is also not a portion of the billowed connections.
After these two portions (of this half) have been glued and dried, slide them out of the way and place panels A, D, and H on the sail. At this point, they should lay flat and line up with the dotted lines on the plan. We are NOT attaching them to the already glued portions... only to one another. See pictures.
Now, there should be three portions of the right half glued up... 1. the leading edge and tip, 2. the tail portion of the trailing edge and spine and 3. the middle portion of the sail that will be the bulk of the billowed area of the sail. Tomorrow I will post my method for glueing up the billowed portion with accuracy. As for every step, pictures and explanation will be included.
Lets see about prepping the rest of the right half of the B'zar for sewing. To recap, the right half of the kite has been glued into three portions distinguished by their relation to the billow of the kite. All that remains is to connect the uneven seams at the middle of the sail. The way the billow is made possible is that the middle panels have been cut with a longer edge then the outer panels. Then, when glued up to the shorter seams (using the same amount of overlap as the rest of the seams), the longer panel forces the fabric to curve (concave or convex depending on whether the sail is loaded or in a stall). The way I've found that works the best is to tape the middle portion to the plan/board along the solid line representing the final glued position. I start with the longer of the seams (seam closer to the leading edge). See the picture to understand what I mean; you'll see that there isn't much difference between the dotted line and the solid one, but this will be enough to put a curve to the fabric. Use lots of tape so that it is as even along the line as possible.
Once the middle portion is taped to the plan, move the upper portion of the sail into position and tape it so that it matches with the outer perimeter of the kite.
Place glue on the panels at the back of the kite... in this instant glue is applied to the middle portion of the sail. Working my way from nose to trailing edge, I glue the upper sail portion in place while systematically taking away the tape... and replacing it over the now glued seam to hold it in place.
Once the entire seam is glued and taped, I place a spar under the sail to hold a small amount of loft to relieve the stress points in the seam. Then I leave it for an hour before I move to the next seam.
The lower seam is attached the same way, and left to dry in the same manor. The billow can be seen in this pic, wrinkled, but present.
The sail will not lay flat on the working surface at this point. Be sure your seams are dry before removing tape. An hour should be plenty of time to wait. Even when the glue is dry, the seams will be fragile, so be careful when transferring the sail from work surface to sewing machine.
Edit/Addition If you have read ahead of this point in the thread, you'll note that the original publication/post shows that I had forgotten to glue the mylar reinforcing panels to the back of the kite prior to sewing. (panel H in our diagram). Because I forgot to glue it on and because I still wanted the strength of the mylar in the sail at this stress point, I attached these panels using a 2x2 zig zag stitch that can be seen in the following pictures. I caught the mistake early enough that the left side of the sail could have been completed properly, but I want the kite to by symmetrical... so I purposefully did the same order of construction on the left. In the future I will do my best to avoid this. Here are pics of the front and back of the sail now that the mylar has been added. Hopefully by adding this portion (edit of this post) you can avoid the same mistake. Now you can proceed.
So the right side is glued up and ready to sew. Some things I will say about sewing... I use v30 bonded polyester sail thread. It is thin, strong and I've only ever found it in 2 colors (black and white). For this build I have chosen to use white, as it stands out and is easy to photograph on a colored sail. If you are building anything other than a white kite, my recommendation is to use black thread, as it tends to cover up simple mistakes (oh, and mistakes are coming. I mentioned in my first thread that I would discuss my own mistakes and what I've done to correct them... stay tuned). Moving on. Proper tension is a valuable thing to achieve. Take some time prior to sewing your sail and make sure you have the tension on your machine set properly to sew ripstop. This is covered in any number of articles, but I recommend this sewing 101 thread commonly referred to for kite making. Sewing 101
Other choices to be made prior to sewing are what stitch you prefer. Easily the most popular stich pattern used in kite making is the 3 step zig zag. This works perfectly fine and is often the best choice. My selection (which may only exist on Bernina machines, I don't know) is a serpentine pattern that closely resembles the zig zag stich, but flows a little nicer visually... in my opinion. See pictures for example. My particular settings for width and length are 5x2 (this is in millimeters on my machine). Choose your width to fill as much as the seam overlap as possible without going over. Note that the serpentine stich is less forgiving (visually) than the 3 step zig zag, as there are more stitches made at the edge of the pattern and going out of your desired stitching zone will be more obvious. As far as needle selection, there is plenty of debate on what is the best. Truth is, I haven't changed my needle in 4 or 5 builds and don't even remember what is in the machine... probably a #12 universal. I find that I get even tension, visually appealing stitches, and few stitching errors so I don't have any reason to change.
The picture here shows that I am using the generic foot that is standard with my machine (I have approx 12 other choices but rarely use something else). I like the generic foot, as I use the widest setting it will accommodate, which gives me some easy visual landmarks. Using visual landmarks to maintain my stitch line has always worked better for me than trying to use fancy machine attachments or different feet. Use what you like. The second picture shows that I'm able to set my machine to stop in a needle-down position. This is important if you ever intend to raise the foot/manipulate the fabric prior to the end of a stitch... helpful in applique and sewing around corners. This is not so critical in this portion of the build, but will be useful when sewing the nose and other fortifications.
So, I'm going to include a few pictures... they come in no particular order. When sewing your seams, it is important to check your bobbin to make certain you have enough thread (don't want to run out half way through a seam... ). As a reference/guide, I was able to stitch both halves and the seam connecting them at the spine on one complete bobbin's worth of thread before I decided to reload it. This first pic shows a couple of things. note the amount of thread I pull away from the machine when I finish a stitch. This allows me to cut the thread and leave enough to tie off the stitch, and enough that the beginning of the next stitch I sew will have threads long enough to tie. It's way easier if you have too much than too little when tying off. The second thing pictured here is how far into the adjacent seam I sew. The idea is that when stitching the perpendicular seam, you'll cross over the end of the first one. This adds a small amount of security should the first stitch ever come loose at the end.
Here is an example of how the stitches should overlap
*Here is my first mistake* not a costly one, and something I will just let be. In this case, it was partially just bad luck that the stitch didn't overlap at that point. odds are that I'll never have a problem with this stitch backing out, but try to avoid this...
The next picture shows the front and back of one seam. Note how evenly the stitch runs at the edge of the seam overlap, on the front and back of the kite. If you're worried about the tolerance and how the stitch will look, choose a stitch width that is slightly smaller than the seam... it will give you less coverage over the seam, but will look better in the end than if you stitch outside the seam overlap.
These last two pictures show where the two panels at the wing tip come together (panels F and J from the previous reference). The first pic (shows front of kite) looks like I came to the edge and then sewed too far... you'll notice on the second picture that by doing this, I've secured both panels completely. Another important thing to remember is that this portion will be underneath the leading edge material and never seen once the kite is completed.
Some of you may be wondering how I finish off the individual seams... what I do with the loose threads. I'll have some detailed pictures coming up with explanation of a surgeons knot and a step that could burn a hole in your beautiful sail (don't play with fire, and don't get mad at me if you burn a hole in your kite... which I have done before, it's not a way to improve your day!).
Pause for just a moment. Is something missing? If you are building along with me, I have been up front with you from the start... mistakes might be made. Is this a drastic mistake? No. Can it easily be avoided by keeping your work space organized? Yes. Didn't I warn you to have an organized workspace? Yes.
Here it is: Don't forget to attach the mylar re-enforcement panels (panels H-r and H-l) to the posterior of the sail prior to sewing. Mine somehow got separated from my pile-of-sail-panels and didn't get attached before the right half was sewn up. My preference would be to sew these with a single stitch that covered the sail and the mylar. To fix this mistake (I may never be any less forgetful), I have sewn my re-enforcing panels on to the sail using a 2x2 zig zag stitch around the edge. The mistake was caught before the left side of the kite went to the sewing machine, but because I love the equality of symmetry, I will attach the left mylar panel in the same manor... after sewing the seam with a serpentine stitch.
Ok, so you've sewn the right side of the sail (after gluing of course). Now on to the left. I'm not going to say much about the left except to mention again (I believe I said this earlier) that the left side will be glued over the plan in the same manor, only now we are looking at the back of the kite... so dark colors should lay beneath light colors. For symmetrical color patterns this is no problem. Edit:as I think about this statement, I realize that symmetry has nothing to do with whether this comes up or not... it's more about the number of colors used in each half and how they're arranged, so everyone should pay attention here. end edit The trick with my color choice is where the billowed seams come into play. Because I chose to glue each half up in 3 sections (top/leading edge, middle billowed portion, tail area) it poses a problem when layering colored panels. To avoid problems, I left the ends (last 1 cm) of seams unglued. It's difficult to see in this picture, but it should be noted that the hi-lighted seam has a portion in which I had to slide fabric between two pieces. Boy if that makes sense to you, I could probably say just about anything.
Let me explain again with as much detail as possible. Remember our reference plan for panels... here it is again so you don't have to scroll back and forth. If you recall, for the last step, we are attaching the billow section (panels A, D and H) to the tail section (panels C and G). if you look at the color pic here, you'll see that panel C is white, and needs to end up at the back of the kite when complete. Because this is the left side, the white should go on top. Same deal for panel H. (still with me?). Because I already glued panels C and G together, I needed to leave a small amount where the seam ends (at the inner portion of the kite... not at the very tail) so that I could slide the billow section between them. This way, both white panels end up in the back of the kite, and all the proper colors end up in the front. So, another way to explain. when looking at the corner that is shared by panels C, D, H and G, panel G is on the bottom (the very front). Next (moving upward/toward the back of the kite) is panel D, then panel H, then panel C.
My hope is to be as clear as possible so this technique is understood. I don't know any better way of describing in words how this is done. If you are an experienced kite builder, you may already know how to do this and I apologize for sounding patronizing. Let's move on.
As this project progresses, you may notice that my documentation is sometimes playing catch-up to reality. I stumbled on some pictures today and realize that if you are using this as a guide to build your own B'zar you might be stuck (this should be treated more as a "for your information" type document. While offering what I believe to be some excellent tips and a record of an actual kite build, due to the chaotic nature of my brain and documentation style, you should probably wait 'til it is complete and read the entire thing before trying to apply what you've learned. I digress).
Where you ask might you be stuck? well, if you've avoided the small, minuscule mistakes that I have made, and managed to start sewing your sail... you may have a bunch of seams with loose threads at the end. This post will explain and show how I tie off my seams. *warning* This process involves fire which can burn you or your kite. This could result in a visit to my workplace (Emergency Room) or the equally infuriating ball of fire that once was your kite. Polyester ripstop of the variety I'm using tends to melt rather than burn. No matter, yours and your kite's safety are your responsibility. Consider yourself warned.
So, you've sewn your first seam and you pull enough thread from the machine to leave significant dangly strands for tying off. You've cut them away from the machine as described. Now, you need to get both strands to the back of the kite so that the tie-off is out of sight. To do this, pull the back strand enough so the front strand pokes through, creating a small loop. See picture and note that it is a straight stitch for an example, but it works the same with your zig-zag or serpentine stitches.
Using the point of a seam ripper or needle, bring the loop all the way through so that now both strands or in the back of the sail.
These examples show me using a hemostat (forceps, needle holder... whatever medical type needle nose pliers you may have) to tie a surgeon's knot... I almost never actually use the tool unless the strands are too small for me to manipulate with my fingers. They do however lend to better pictures and explanation.
The next pic shows that you make two loops around the hemostat:
Then, with the one strand looped around the tool (and holding the strand in place), use the mouth of the pliers to grab the loose strand.
Now bring the loose end through the two loops.
Make sure the loose strand comes all the way through the loops before you pull it tight... it should look like an overhand knot at this point but with one extra wrap.
Now you can pull it tight. Before cutting the strands, I repeat this process for a total of 3 knots. To be really specific, I alternate the directions of the loops between each knot; this is how an actual surgeon ties off sutures and it works for them so... I then cut the loose strands short and melt the ends with a lighter. You can hold the flame close to the kite without igniting the polyester, but know that you can absolutely burn holes by doing this (especially if fabric goes above/over the flame). I can't picture this technique without an extra person (or because I'm too lazy to set up a tripod with a timer). You don't have to melt the ends, but I prefer the cleaner look, and it will be less prone to coming untied.
The next step, now that the individual halves are sewn, is to attach them at the spine. The B'zar has a curved spine. You may have noticed at this point that the edge of the plan that represents the spine is not straight. This is not a new concept, as Chris Derefat has been incorporating it in his designs for a while now (Quartz, Organic, Vortex etc.). The curved spine helps tension and shape the sail without creating folds or wrinkles, and helps take up any unintended extra material that might form a "dent at the upper spreader" according to the B'zar website. The traditional/common way of attaching the halves of a kite together has been to have an overlapping seam identical to the other seams on the sail... using a zig-zag or serpentine stitch. For this build (and other's I've done) we're going to do something a little different to ensure that the seam is smooth and even.
Start by taping the right half of the sail to the plan as accurately as possible (tape all around the edge). Then place the left half on top of it so they are evenly aligned. (front faces of each half should be together, see picture)
Then glue the spine together and tape for drying. I use the same gluestick I've been using, and place glue in a strip approximately 8mm wide at the edge.
Sewing machine setup is important when stitching the spine. You should either have a guide you can place on your machine; at least a visual guide should be used in order to maintain a stitch exactly 8mm from the edge of the fabric. I'm lucy that from the center of my needle to the edge of the standard foot on my Bernina it is exactly 8mm.
Stitch the seam using a straight stitch. I chose the default 2.5mm for my stitch length.
Now that you've attached the halves at the spine, you need to reinforce the straight stitch. Do this by opening the kite up and folding the flap of the spine to one side or the other and sew it down using a serpentine or 3 step zig-zag stitch. Remember that the straight stitch is the actual center of the kite and the serpentine stitch will be to one side when complete. It is important to remember that for measuring later in the build.
When sewing the flap of the spine down, I roll the half of the kite that will fit in the arm of the sewing machine so the fabric keeps from wrinkling or causing an error in my stitching.
Now that the spine is sewn together, it's beginning to look like a kite!
The sail is sewn into one whole piece. Good. There are some things that have to happen before we attach the leading and trailing edges. Because I want to have the edges be the most outward layer (with the exception of the finished nose, but that is another post... or two) some reinforcing needs to be done prior to sewing on these parts. The flow of construction should be done from the inside out (at least that's how I think of it in my head). So, the next step for me is to reinforce the nose.
There are a number of options/paths you can take to build up the nose on your kite. Some use a panel of mylar. My preference is to use an additional layer of PC31. It serves the purpose of adding additional strength to the nose area, but I find that I like the flexibility of the material. At the nose, the fabric will have considerable amount of curve when complete and I like it to not get heavy creases in it as I've seen happen with mylar nose panels.
To start, I mark the center seam on the kite at a few places... approximately 1cm down from the tip and 6cm down from the tip on the back side of the kite.
I then dig through my box of scrap fabric and find a piece of PC31 that will fit across the nose... it has to be long enough to cover the 6cm mark by about 1 extra cm, and wide enough that it covers the nose all the way across both leading edges. I found that a rectangular piece about 4 inches tall and approximately 12 inches wide will satisfy this requirement. I square off the lower edge of the scrap so that the bias runs in line with the center seam. I chose the color white so the panel would not be seen from the front of the kite. If you have another color at the nose of your sail, either choose white, or the same color as the sail at this point.
Next, using a straightedge and running it perpendicular to the seam at the 6cm mark I just made, I find the point on both leading edges where the straightedge crosses at equal lengths from the nose. I found this to be at 18cm down the leading edge. I mark this point on both leading edges so that I will have my nose reinforcing panel lined up properly when I glue/sew it in place.
Now with the sail properly marked, I glue the nose panel in place... pointing towards the tail. "hmm... towards the tail" you may be thinking. I line up the first line of the bias over the two leading edge marks and glue to the kite as pictured. You'll see why in a minute.
Sew the panel in place using the bias as a guide (and still aligned towards the tail at this point). I use the default straight stitch setting on my machine, which is a length of 2.5. After I make this stitch, I fold the panel up towards the nose. This will hide the bare edge of the panel and have a cleaner look when the kite is complete. After folding the panel toward the nose, I mark each of the lines of bias that I will stitch to keep the panel in place. I use a black sharpie, as it's easy to see these marks when I am lining up the fabric to sew.
Once I've sewn my seams (lined up with the bias, or 1 cm apart) running up the nose, I have a lot of extra material. When I cut it off, my choice is to hot cut it. I also remove the tab at the nose that was created when I made the seam for the spine... which was folded over and left some material sticking out. I cut off the excess material with a hot cutter and a metal straight edge.
Coming up... before the trailing and leading edges, I'll show how I protect the spine/center seam of my kites. It's pretty straight forward, but there are some small details I want to mention that I've found to be beneficial when building.
Many kites on the market today have patches on the front and the back of the kite where the center T is located and where the Upper Spreader cross the spine. These patches are created from a variety of material including dacron, velcro (usually the soft side), mylar and seatbelt webbing (and probably more). Instead of cutting individual patches that need to be lined up front to back and be sewn, I prefer to make a 1" mylar strip that runs down the back of the seam. For the front of the kite, I use a strip of 1" dacron that spans the entire length of the seam. Furthermore, I make the dacron strip long enough that it can fold over the nose, toward the back, becoming a pocket for the nose end of the spine to rest in.
This picture shows how I set up to cut a 1 inch strip of mylar. I line a mylar sheet up with the edge of my metal table edge and tape it down. Then, using a 1" wide aluminum straightedge (you too can own one for approximately $6 at home depot) all I have to do is line the straightedge up with the edge of the table and run the hot cutter along the other edge. Easy 1" strip. The mylar strip should be long enough to overlap at the nose and tail of the kite when attached (it will be cut to size after sewing). I believe I got the job done with a 36" strip, but don't take my word for it, measure for yourself by comparing to the sail or the plan.
Once the strip is cut, I use a sharpie to mark the center. I prefer the metallic/silver color, as it tends to be less noticeable when the kite is complete. For the purposes of this documentation, I used a black one in a few spots so it can be seen in the photos. Marking the center helps you line the mylar strip up exactly with the spine seam.
Remember that when I completed the seam running the length of the spine that I mentioned the straight stitch is the true center of the kite... not the serpentine strip used to reinforce the seam. Keep that in mind when glueing the mylar to the back of the kite. (and do make sure it is the BACK of the kite).
Glue the strip using the same gluestick used to attach the sail panels to one another. Don't sew the mylar on yet.
Oh, and are any of you wondering why I put a mark at 1 cm from the end of the nose during the last portion of this record? This is just a reminder that it is not to be forgotten!
I would say with confidence that most kites utilize separate patches on the front of the sail to protect the spine portion of the sail (located at the center T and where the upper spreader rubs against the sail). My preference is to use one long piece of dacron to protect the entire seam. In the previous post, I shared how I protect the posterior of the spine with mylar. The next few pictures will show how I complete this process by sewing the front and back reinforcements together at the same time.
To do this, I cut a portion of 1" dacron approximately 36 to 40" long. (I compare to the sail and give myself 4 or 5 inches of slop at the nose and tail). This dacron is sewn to the sail the same way as the mylar on the back of the spine. Remember that a hole will need to be cut at the center T for the connector to pass through the sail, so 1" might not be as wide as some people would like. I think it will work fine in the end and have a cleaner look than if I use a wider piece.
When gluing on the front strip, I use the already glued mylar as a guide to make sure they line up. This is important since they will be sewn on together. I also place something in the tail section to hold the curve of the spine (exaggerated while gluing, but good for keeping wrinkles to a minimum)
Ok... so I've been procrastinating with this next section due to the fact that it requires a very minor deviation from Werner's plan. I think one of the great things about kite building is that final products are always compilations of ideas and techniques. Leading edge pockets, leading edge tensioning/wing tip design, spine tension, standoff reinforcements, panel fortifications are all subject to the builder's preference. If every builder had to come up with original ideas of how to do this there would never be any kites built. In the case of this kite, I am choosing a slightly different style of nose construction than is described by Werner and Hugo on the B'zar website. For this reason I am being very clear This portion of the build is different than the designer intended and I do not encourage anyone to sway from the plan!
Alright, there. I said it. I swayed from the plan. The rebel in me couldn't help it. Explanation is needed. Werner's plans indicate that when completing the stitching for the nose, the spine pocket should be stitched 1 cm from the end... preventing the spar from sliding all the way to the tip of the nose. The reason for this, as stated on the B'zar 2011 web site is so that"both Leading Edges can come a little closer together". My preference, and the means in which I'm deviating from the plan, is to cut off the top 1cm of the nose entirely and letting the spine slide all the way to the end. This results in roughly the same idea that the leading edges will curve closer together, but it will create a more rounded nose rather than a pointy one. Because I have not completed my build (let alone 2 kites to compare) I cannot tell you how this will affect it's flight behavior. My feeling is that it will be a very minimal impact on the way the kite performs. If it is important to you to have exactly what Werner intended, do not do the things I have done!
Whhew! Glad that's off my chest. Did I mention that I don't condone swaying from the plan? (I should also note that if you dare to follow me outside the lines, you may need to adjust your frame dimensions... but we will get to that and it will be a minimal change... millimeters at most).
OK, so "why all that explanation now", you might be thinking... and if you're still with me and not completely sick of my writings, you'll see why in the next picture. One of the tricks I've adapted by using a single long strip of dacron for my spine reinforcement is that I wrap it over the nose which also creates the first layer of the nose pocket... because of this I needed to cut the nose to shape at this step rather than later on. I cut it exactly 1 cm from the tip so the pocket will be the same length as if I had sewn the 1 cm stitch as the plans indicate. And this is why I made the 1cm mark on the sail during the previous nose fortification steps. I'm also very careful when cutting the nose off that I don't cut the dacron strip with it... a smart builder would cut the nose before gluing the 1 inch dacron to the front of the sail.
In the last picture (just above this text), you'll see the now flattened nose is approximately 3 inches wide. You'll also see that the straight edge is placed at 1 and 1/2 inches away from the nose (measurements on are marked on the cutting matte; every square is an inch). This is where I trim the dacron. In the next picture, you can see that I fold and tape the remaining dacron tab down to the posterior of the kite. I cut a piece of tape narrow enough that it will not be stitched to the kite when sewing the spine seam fortifications in place. The tab I just taped down should not have any glue on it, as this will be the inner most portion of the nose pocket for the spine.
OK, so everything is glued up, taped up, ready to sew. I start at the nose using a straight stitch (it will be reinforced later when I sew on the heavier nose material). Then when I reach the end of the nose pocket, I switch to a 2x2 zig zag stitch for the rest of the seam. I then sew the other side securing everything in place. I'm particularly careful when sewing this portion, especially with white thread on black material. Any mistakes in sewing will be quite obvious when observing the kite up close. (using black thread helps to hide imperfections but is harder to photograph for this reference).
ok, are you still with me? Do you forgive me for swaying from the plan? I hope so. Next up will show how I stitch the velcro strap for the tail end of the spine... then I'll move on to the trailing edge.
Here are some things I want to show before I move on to describing how I attach trailing edges, leading edges etc. Before I do anything else, I lay the kite out on the plan and make marks with a silver sharpie that indicate attachment points on the completed kite. All the points I mark are: Center T connection, Leading edge connectors (upper and lower), Yo-Yo stopper placement, and standoff connections at the sail. I do this now so that it is easier to locate these spots when the sail is complete. Make sure your marks are long enough to extend past any fabric you may sew over them (if you choose to do this). The pics show some examples.
The other thing I realize I forgot to mention is that the tail end of the center seam reinforcement needs to be trimmed to fit the profile of the sail itself. I use a straight edge and a hot cutter. Very basic, but be careful not to alter the shape of the sail.
Another step (or set of steps) that can be taken prior to sewing the trailing edge is putting together the tail strap. There are a number of ways this can be done. Many people/designers build strap that is incorporated into the spine fortification/center T reinforcement. If this is the way you prefer, then your tail strap is technically attached to the front of the kite, wraps around the bottom of the tail and attaches to a separate piece of velcro that is connected to the posterior of the sail.
Because I use a long strip as my sail reinforcement, my choice is to make a tail strap that attaches to the rear of the kite. This way I can sew the entire thing off of the kite (including the small velcro tunnel for the spine). Also, by attaching the strap to the back, it is completely hidden from the front view of the kite and I feel like this is more appealing in terms of the details regarding the trailing edge and tail end of the spine.
To start, I cut the hook and loop pieces at approximately 2 inches each. The hook portion tends to curl up as it is more of a plastic material, so I tape it down when I cut it so it remains flat. I know it's hard to tell from these smaller pics, but the loop material is the first pic and the hook is pictured second... To cut these, I use a hobby knife. No need to hot cut these pieces.
I then take a 14.5" portion of 1 inch wide dacron and cut it... I chose white here, but any color can be used. White will not show through as much as the black would in my chosen checker board type color scheme.
I then fold the dacron at two places... one fold at 1/2" from one end. A second fold at the center of the remaining material (or 3.5" from the opposite end).
Now, using 1/4 inch tape, I place two strips that span down 1 half of the strip. I make sure I leave an 1/8 of an inch at the edge so when I sew the fabric I am not sewing through the adhesive. Then I fold the strip into it's final form with the 1/2 inch tab folding over the top of the exposed end.
Before sewing, I stick the hook and loop to the strip. The hook portion (harder rubber adhesive material) sticks over the folded tab of the strip to hide the edge. The loop portion needs to be taped down to the end of the strap in a manor that the tape is not sewn through in the next step. Also, I make sure that I leave a small amount of the tab sticking out beyond the loop material so that the tunnel for the spine is not sewn shut.
Next, I sew the entire perimeter of the strap with a 2x2 stitch (with the exception of the end that will face the nose... this is a straight stitch, in order to leave the spine tunnel created by the loop material open).
The strap will be connected to the sail after I've attached the trailing edge.
The trailing edge seems like a pretty straight forward thing... right. Take some material, fold it in half and sew it in place. Easy. I have, as I tend to do, made it slightly more complicated for myself. The idea remains the same, but I've chosen to try some new things for this build that may make it more difficult.
Most kites have a nylon trailing edge with various styles of dacron reinforcement to prevent wear. For this build, I'm opting to use dacron along the entire trailing edge so as to avoid the fate of many kites (most commonly the zephyr I believe) in which the material frays over time. This choice has it's downside too, as it very well may cause increased wear on the bridle. It is always my preference to replace a bridle than a portion of the sail, so I am ok with this compromise.
The second means in which I'm swaying from my normal build process (which was to use 1" nylon folded in half) is to cut the material from 1 inch down to 3/4 inch. This will result in nothing more than a tidier look on the completed sail... and perhaps save a minuscule amount of weight that is gained from using darcon over nylon (although I believe this is a negligible difference).
To cut the 1 inch dacron down, I tape a length of it along the edge of my work table; taped in multiple places to keep it as straight as possible. Then, I tape an aluminum straightedge to the table so that it covers the portion of the dacron I want to keep. Using a hot cutter, I remove the 1/4" of material that will be waste.
Once I've cut enough dacron to cover the entire trailing edge in one piece (with approximately 4 inches of extra material) I fold it in halve. To do this I crease about 10 cm of material at a time and run it against a sharp corner of a table or the hardboard the plan is attached to. (note that these pictures are from another build and that they show me folding nylon material... not the dacron I used for the Bzar 2011).
Now I'm ready to sew the dacron to the sail. I find the middle of my dacron strip and make a fold across the short length of the material. I then place the tail of the sail at this point and start sewing one half... from tail to wing tip. I use a 2x2 stitch and I sew in a few stitches forward, then backward to secure the thread at each end. It's important to leave enough space between the stitch and the trailing edge that the leach line will be able to thread through later in the build.
Here you can see the wing tip. As I stated before, I leave a length of extra material that can easily be trimmed off once the trailing edge is sewn in place.
Some people tape the trailing edge in place before sewing, or use hair clips (or other means to secure). My choice with the smaller material of the trailing edge is to just hold it in place as I sew and go slowly, making sure the sail sits all the way into the fold of the dacron as I go. Once I've stitched one half of the trailing edge, I secure the thread and reposition the kite so that I start at the tail again and sew the opposite half. The tail looks like this when completed. (note that a small portion will be cut off later to allow the leach line to come through to the back of the sail).
I have some pictures of what I have done with the lower spreaders. First off, the biggest advice I can give about cutting a frame is to measure twice... then measure again, then make your cuts. The other thing I do is I cut all of my frames slightly longer than spec (by about a millimeter or so) which allows for some adjustment for finish work.
Start by measuring. Measure twice. Have a method for measuring. I use the same measuring tape to measure the entire frame for consistency, but I also compare measurement marks on each identical spar before I cut. To mark where I will cut, I use my trusted metallic/silver sharpie. Here you can see that I've measured and placed a mark on one lower spreader at 765mm... I've marked it so that when the cut is made and finish work is done, the mark will have been removed. Remember that whatever you use to cut your spars (I use a dremel tool), the width of the tool should be considered. If you cut on the wrong side of the line, your spar will be 2 to 3 mm too short. I mark all of my spars in this way and always pay attention to which portion of the spar will be the waste. With Nitro rods, you can cut either end to an extent. I know Ken McNeil cuts off the big end of his Nitro spars. For this build, I'm going to cut off the small end for two reasons. I am in the habit of cutting of the small end (I usually use 5pt or 3pt spars for my builds and with those spars you should only cut the small end to avoid problems with ferrules). The other reason is that the spar will remain slightly stiffer if you cut off the small end... or be more flexible if you cut the big end. For consistency, I'll reiterate: for this build I'm cutting the small end of my nitro spars.
Before I cut, I mark both spars (in this case, both lower spreaders. To mark the second spar, I butt the end of the spars up against a straight edge and then use the mark on the first spar to put the mark on the second. See pictures.
To cut my spars, I place them in a small vice on my work surface. Please do not try this at home and come to me when you've crushed your $20 Nitro Black Diamond spar in your vice. A bench vice will easily crush your carbon spars!!! The key is to tighten down just enough to hold the spar in place... this allows you to use both hands to control your dremel tool for cutting. (if you're going to use a hack saw to cut carbon, get the highest tooth count blade you can fine. I've had decent luck using a 32T per inch blade).
Once I cut the spar, I have a rough edge and I can still see the mark that indicates the spar is approximately 766mm long. then using 120 grit sand paper, I bring the spar down to the right length and taper the end so it slides easily in the APA spread and has less of a sharp edge (to keep it from snagging on the sail or my skin). Note that I sand the end of the spar until the measurement mark is removed, then I taper the end. This way I know that the spar is exactly the right length. Don't hesitate to measure with a tape measure (or straight edge) to avoid sanding too far.
Later on I'll give some detailed photos of how I ferrule the lower spreaders on this kite. It is a process that can be done 1 of two ways. You can use a .28" solid carbon spar for a ferrule (which will fit in the large end of the nitro spars, but require you to drill out your center T connector). My choice is to use a .240 solid carbon spar as the ferrule, which will require a shim to fit snugly in the spreader... for a shim, I use a portion of p100 spar glued into the large end of each spreader.
However, the next step is to place the leech line. My choice is to use 100lb bridle line, although I have a number of kites that use heavy Spectra/Dyneema. I know bridle line is expensive, but I use it because it is easier to sew in place at the wing tips. (if you plan to use spectra for a leech line, I would recommend looping it around the wing tip nocks as done in the prism zephyr or flying-wings silverfox kites.)
To start, I measure a length of line using the plan... I measure out a single length that equals the distance of the entire trailing edge + the distance from the tip to the center T + about 3 inches of extra to account for any error. Once cut, whatever line you use will be frayed at the end. Melt the end with a lighter to prevent the line from unraveling.
Now, before you thread the leech line (I use a tapestry needle), you need to cut the tail of the kite just enough for the line to come through. Pictures show tail before and after the cut...
Now thread your leech line through the trailing edge. Work it through from one wing tip to the other. When I get to the tail, I pull a significant amount of slack through the first portion I thread... it makes it easier to work the line through the second half of the trailing edge.
Once the line is threaded through the entire trailing edge, I pull up any slack at the tail so the line is flush with the wing tips. Then I sew in place to look like this at each wingtip.
Here you can see the tail with the leech line coming out. I had to cut the tip a little further back than the previous picture so that I could thread the thick line into my dacron trailing edge.
Thats it for the trailing edge (right now)... about the last thing I do on the sail is sew on the standoff re-enforcements. I don't know why I wait, it's just habit. So I will go over that later.
Now, let's move on to the leading edge. The leading edge, along with the nose is one of the hardest parts to place on the kite in my opinion. The cutouts for the leading edge to standoff connectors need to be cut precisely, and the sewing of the leading edge will be visible once the kite is complete (and it is difficult to sew and keep the fabric in the right place). It should be said that I will typically use black thread to sew on the leading edge, but for this project, I've used white so that it can be seen.
To start, I measure out two strips of 2" dacron (in my case I've used mylar coated dacron, but most of you will not have this material... regular dacron is fine). I measure it out by taping it to the plan as seen here.
It is important to add about 1.5" to the length that will be folded over to re-enforce the tip.
Before removing the strip of dacron from the plan, I make marks where the leading edge cutouts will be. I've marked my plans where the spreaders will intersect, and adjusted the cutout spaces accordingly (I've made the cutout space slightly longer than on the plan, as a larger cutout will give a more gradual/smoother line along the leading edge).
You should also note that the lower spreader cutout is a little bit off from where Werner intended it to be... this is noted on his site. I have not pictured my plan in it's marked up state, but be sure to view the framing diagram on the site to see exactly how far from the upper spreader the lower spreader should be placed. Adjust the cutout accordingly. Also note that I have made a mark for the yo yo stopper... I will not be cutting out this section, but I will make a small hole for a zip tie to pass through.
Once you have one of the leading edges marked and cut to length, I tape it to a table and tape the next piece (for the other side) right next to it and mark the second strip to be symmetrical to the first.
Once both sides are marked and cut, I fold them in half lengthwise. Then fold over the 1.5" tab at the end (note that for my next build I may increase this to 2 inches for the additional length of re-enforced wing tip material.
Now, with the wing tip folded over, and the leading edge folded in half, there is a small amount that sticks out annoyingly. simply cut it off with a straight edge and razor blade (then pass a lighter along the edge just to keep it from fraying).
With the leading edge cut to length and folded, I then prepare the spreader connector cutouts. I like to have a covered connector to avoid snags while flying (as do most of the kites on the market at this point). Usually I cut out a slot in the forward facing portion of the leading edge at the connection point for the upper and lower spreaders... for this build I'm going to try an idea I got from my recently purchased Silverfox Pro. Instead of cutting out a slot, I'm going to only cut two holes for the spar to pass through. This will be more obvious from pictures if you're not familiar with the Silverfox Pro.
First, I found a washer that has a half inch hole (large enough for a P200 with a vinyl end cap to pass through). The point of the washer is to be a guide for my soldering iron/hot cutter.
Having already marked the leading edge strip, I cut 4 holes on the half of the strip that will be on the front side of the kite (two holes for each spreader connector. Make sure you make each strip symmetrical. The first pic shows the upper spreader portion, second pic shows the lower spreader portion. Remember that soldering irons will burn through your fingers as fast as the nylon material you intend it to cut... be careful and don't give yourself a reason to visit the ER.
Notice that with the upper spreader, I've put the holes on the outside of my guide lines with the connection point centered between them. For the lower spreader, I've biased the holes towards the tip... this will allow a small amount of extra sliding room when taking apart the leading edge if needed. (I usually store my kites with the leading edge at full length, but do occasionally break them down).
Now, to finish prepping the leading edge, I apply double sided tape that will hold the fabric in place while I sew. I place tape on the back facing half of the leading edge, close to the fold so it is easier to attach the sail. Then, between the holes I cut for spreader connectors, I place a piece of tape on the front facing half of the leading edge directly between the holes... taping in this way will help when piecing together the frame.
The leading edge is now prepared to attach to the sail. This seems like a good time to explain that I had some trouble sewing the particular material I used for my leading edge. My trouble came in that the folded material did not want to feed evenly (a product of my sewing machine and the glossy/slippery mylar surface of the material I used). For future builds, I will also be gluing the leading edge as I did the sail panels. My sail is complete, but not as beautiful as it could have been had I glued the leading edge in addition to taping it. I also used white thread on the leading edge for the purpose of this documentation... in the future I will use black to match the material and hide any flaws that come up while sewing.
Now we take up the preparation of the leading edge. I set those pieces aside long enough to sew on the tail piece/spine tunnel.
Using double sided tape, I attach the tail strap to the posterior of the kite at a pre-measured distance. The picture shows that it overlaps the kite by approx 3 inches. The placement is not arbitrary. To find the exact spot in which the tail strap will sit, I fold it in half with a mock spine (and tail piece) slid into the velcro tunnel. I then place it on the sail such that the leech line will have a very slight curve in it when it is wrapped back toward the center T.
Unfortunately, I have forgotten to take a picture of this step, here is the strap stuck to the sail prior to sewing. Note how it exactly matches the mylar spine seam reinforcement. Also note that I have used a sharpie and drawn 2 diagonal lines that I will sew over. The point of these is so that I do not sew through the leech line at the tip of the tail. They also follow the seem in the trailing edge, so the thread will be somewhat disguised on the front aspect of the kite.
To sew the strap, I turn the sail so the front is facing up. Care must be taken so as not to displace the strap, as it is only attached with fabric adhesive tape. I start at the very tip of the tail, and I use the seems on the trailing edge and the spine re-enforcement as a guide. My machine is set to the default straight stitch. This will make it easy to follow the existing stitches and it will ensure that I have enough width in the spine tunnel for the spar to slide through. Sew slowly and make sure the machine is set to have the needle down when you stop. This way you can make the corner without having the thread go crazy.
After making the first turn, I follow the outside edge of the zig-zag stitch on the spine. Stitching up to what will be the top of the spine strap/tunnel, the stitch length may need to be adjusted before making the turn. It is crucial that you make the turn early enough that the top of the strap will be secured, but late enough that you will not stitch the tunnel closed on the back side.
When securing the top of the strap, as you stitch across the spine, the stitch length may need to be adjusted again to land on the exact far edge of the spine stitch, so you can have symmetry and a guide to stitch back down the other side of the strap. See where the needle is stopped just before I turned back towards the tail.
On the return stitch, prior to making the last turn to complete the stitch, cut off the original threads above and below the sail so they don't get sewn into the stitch when you reach the end. It wouldn't be a huge problem to sew over them, it's just not as aesthetically pleasing.
Here is my completed stitch. Please ignore the holes at the top, as I had a first attempt and found that the strap was to far up, so I cut the original stitch and re-did it. Note how the straight stitch follows the previous zig-zag.
Ok. I must apologize now... I have misplaced some of the pics that I took to document the leading edge portion of this build. I have some for taping the leading edge to the sail, but have lost the pics showing how I glue the leading edge, and how I sew it to the sail. I will show what I have.
As shown before, I place fabric tape on the back side of each leading edge, close to the fold (center). I start at the wing tip and remove the first portion of tape backing. Being sure to line up the sail wing tip to the very tip of the leading edge material, I begin to stick the sail to the edge. Good lighting will help with proper placement of the sail, which should come right to the center fold of the leading edge.
I then work my way to the nose... removing tape backing a little at a time and placing the sail fabric over the top of it. Always being sure it is flat with no wrinkles and pressed into the center of the leading edge.
In the next pic, you can see that my frame markings on the sail line up exactly in the center of my frame cutouts in the leading edge. Also note that I do not peel the tape on the front portion (between the cut outs) of the leading edge until I've completely taped the sail to the back of the leading edge.
As I get to the end, you'll notice that I have given myself approximately 1 inch of extra leading edge material. It will be cut off prior to sewing on the nose.
Repeat this portion with the opposite leading edge. Note that you will be working in the opposite direction, and be sure you are oriented front and back before you begin to tape. (I have made the mistake of having my frame cutouts in the back of the kite on previous builds... don't make this mistake).
Because I have lost some pictures, I will make some recommendations now that will not have visual aids to support them.
1. It is important to secure the front portion of the leading edge to the sail as well. I use a glue stick, and apply it to only the portion of the leading edge that will be sewn... no glue should be placed where frame material will end up. I avoid tape in this area, as it gums up my sewing machine. The reason to secure this flap is to help with the evenness of sewing/feeding through the machine. You will note later that I had some feed problems and they will be seen in the unevenness of the stitch near the nose on each leading edge. I will point this out later. To avoid this problem, I would do as suggested in a response to this thread... place some masking tape over the glossy portion of the leading edge for sewing. This will help it feed evenly through the machine. I've never had this problem with the mylar free dacron I have used in the past.
2. For this build I chose to use a serpentine stitch for the leading edge. This proved to be a mistake, as I have had much better success using a regular zig-zag stitch in the past. I would recommend a zig-zag stitch and will use it in future builds. I also used white thread in order to show the stitch (although now I regret it as the pictures have been lost for the sewing of the leading edge). I much prefer to use black in this portion... and will in the future.
3. remember to remove the tape backing on the front half of the leading edge (which will keep the portion between the frame cutouts from coming up when threading the leading edge frame through the tunnel later on. I would also not discourage anyone from sewing this portion with a single straight stitch to ensure a permanent bond.
I'll show you a quick close up of the wing tip detail. Note that in these pictures I have punched two holes in the wing tip that will be the anchor point for the leading edge tensioning.
The important thing to take away from this is the stitch pattern on the leading edge. I start near the center of the wingtip, work my way down, back stitch to the center, stitch down again, then make the right angle to stitch toward the nose. when I reach the end of what would be the folded back portion of the leading edge material, I switch to the serpentine stitch (zig-zag on most of my builds, but serpentine for this one). Of course there are other ways to start the leading edge seam, but I like this way because it is simple. I would admit that I have probably done this slightly different with each build and may someday land on a style I stick with.
Now, lets look at the nose. And remember my disclaimer ** this is a variation to the plan **. I start with a piece of seatbelt material (not the only choice of material, but it was easy to get locally when I lived in Seattle, so thats what I use at the moment). I used 2" wide material for this build, but have used 3" material with equal success and aesthetic value. I cut the material long enough that when folded over it will completely cover the nose of the sail with some slop (in this case approximately 12"). The initial piece is cut with scissors, as I hot cut the nose to shape after it is sewn on the sail. I fold the material in half and crease the fold as best I can for reference. Then I apply some adhesive tape to both halves (long way) to hold the nose in place for the first seams.
At this point, I center the nose on the sail and fold it over so the tape holds it in place. Note in this picture the length of nose material. Also note the unevenness of the leading edge stitches from left to right. These seams were sewn using the same stitch settings on the sewing machine, but due to some issues I had during sewing (feed issues) they turned out this way. Also be assured that I will never point this out to anyone again.
The first two stitches I make are lined up with the spine fabric. I don't mark anything, I just eye it and go. I go down, back and down again for both stitches and then tie off the thread. Again, I normally do this with black thread so the stitching doesn't stand out. It's hard to get good even stitches when you are stitching forward and backward. To avoid messy stitches, you can stitch down... rotate sail 180 degrees, stitch back, then repeat (it is easier to guide the stitching in the forward direction because you can see where the needle will hit the fabric). Laziness has kept me from making theses stitches pristine. Later when the frame is in the sail, no one will care except for me and fellow kite makers with an eye for these details.
The next stitches are made in the same manor. They are the seams that the leading edge frame material will butt up against, so I recommend multiple passes here as well. To determine their angle, I do make a small mark on the leading edge that can't be seen in the pictures. I set the seams so they are perpendicular to the leading edge at the nose. I start the sewing at the edge and aim for the end of the first stitches I made (as you can see in the picture).
Now, before making more stitches, I cut off the excess material. I use a metal straight edge and a soldering iron to hot cut the material. By hot cutting, the edge is melted together. It is a little bit of a trick to line the edge up with the leading edge material and not melt the area you want to preserve. Just be sure before you cut. Fewer passes with the hot cutter is best, but may take 2 or three passes unless you have a better tool than I do. As you make more passes, the material will melt, but it will also start to get thicker as it melts back... also be sure you have the material on a surface you don't care about (as with any hot cutting).
I do make two more stitches on the inside of the leading edge going toward the tip of the nose. These stitches keep the nose material from flapping out when the frame material is inserted. I follow the leading edge and just eye it while I sew to get the line.
It is important to sew the outer leading edge of the nose even though it is melted together.
The last picture shows the nose after all the extra fabric has been trimmed away. Something that always seems to happen to me is that when the kite is flailing around (and please don't mistake me for a skilled flyer... I really do mean flailing), one of the lines catches on the nose fabric no matter how close I hot cut it to the leading edge. See close up for the spot that is the culprit.
To avoid having the lines catch here, I figured I'd try to imitate some other kites... Paul Shirey's kites, Silver Fox pro etc. The goal is to stitch a piece of dacron over the jagged edge of fabric. Don't be misled into thinking I do a good job at this, and don't mistake it for the way other builders accomplish similar outcomes by bringing a portion of the leading edge to the outside of the nose (Sky Sport Design, Skyburner and others). My point is that this is one way to do it and with practice, I believe you could make yours look more beautiful than mine. The first thing to do is cut a pieces of 2" or 3" wide dacron in a strip approx 4" long and fold it in half like you do for the leading edge.
Then, lay it in place so it folds around the problem area of the nose and sew a seam approx 2mm from the leading edge. You can see that the flap will be huge and that I sew down and back a few times (not beautiful, but functional). When you sew, you want to pull the fabric in as tight as you can to eliminate any wrinkles on the edge.
Once you've sewn the dacron in place, use two metal straight edges and cut off the excess material as close to the seam as you can (or as close as possible without letting the stitch break out). This will dull your blade, so I keep a fairly large stash of new blades for future use.
Finally, after all is trimmed, here is a picture of the finished nose as I have built it (please ignore the stitching). Remember that this is different than the original plan, but will result in the same frame specs but the sail is 1cm shorter at the nose.
Just a couple of steps left to finish the sail. To cut out the hole for the center T to pass through the sail, I use the same washer I used in my leading edge cutout. I locate the mark I made on the front of the sail and I cut two holes, one above the other... I notice now looking at the pictures that I was just a little off center; not a huge deal, but it will be aesthetically more pleasing if they are centered. Avoid this mistake by drawing cross marks to more easily center the washer when cutting.
Once the holes are cut, I use a straight edge to take off the small tabs on the inside... resulting in the oval shaped hole. In the future, I may pay to have some stencils made for these type of holes, as I always to the same side for all of my kites. For now, this is sufficient.
Then, as you've already seen the wingtip detail, I melt two small holes in each wing tip at 1 and 3 cm from the end (on the leading edge side of the seam). I use the same soldering iron I use to hot cut my fabric, and I make the hole just large enough for a strand of dacron cord to pass through it. These will be used to tension the leading edge. In the past, I've used only one hole, but for this build it is my intent to more evenly distribute the stress of the leading edge tension over two holes to hopefully maximize the life of the fabric. I will show how to tension the leading edge near the end of the build.
Ok... time to finish this sail. Really the only thing left is to add some small tabs that will act as standoff re-enforcements. I made these out of dacron. in past (and probably future builds) I tend to put these on the sail before I attach the trailing edge, but I forgot in this case, so I'm adding them at the end. Further more, I would usually have them wrap around the bottom of the trailing edge, but due to the fact that I have mylar re-enforcements in the sail, and that I used dacron for the trailing edge, I'm only putting these tabs on the front side of the sail. I start by cutting these pieces with a straight edge and a hobby knife (I do use a lighter to lightly singe the edge to prevent fraying).
I then sew them onto the sail on the front side, overlapping the trailing edge and using a straight stitch. this way, if I cut through the seam of the trailing edge when I cut the standoff hole, I have a straight stitch that will keep the trailing edge seam from coming out further.
Then I cut the hole for the standoff. I cut a hole slightly smaller than the post on the standoff connector... and then use a hot cutter to melt the edge of the hole to a size that the standoff connector will fit in (snuggly). Here is a picture taken prior to melting the holes to there larger size.
Now on with the frame building technique. Showing the specifics for the lower spreaders was done earlier.
1. Measure twice. Anytime you're going to cut any spar (especially the expensive ones), measure twice and make a mark that is easy to see.
2. Be consistent and take into account which side of your easy to see markings you will cut. The width of whatever blade you use to cut can be 2-4mm of difference in your spar length if you cut on the wrong side of the mark.
3. I cut my spar to have a little slop (1-2mm extra) so that I can sand it down to the finished edge.
4. Io finish, I sand the spar to length, then sand a very sort taper to smooth out the end.
For the lower spreader I opt to shim the large end of my nitro spar with a portion of p100 so I can use a .240 solid ferrule. (this saves me from having to drill out my center T). So, I first glue the P100 shim onto the ferrule itself (this is not reflected in the pictures). First, I cut a ferrule so that there is enough length to cover 2" in each lower spreader, plus approximately 1/2" for the width of the center T. I don't really have many pictures of the lower spreader being constructed, but here is one showing the expanded (none glued) ferruled spreader so you have an idea of how it goes together. I glue the p100 to the ferrule and clean off the excess glue, then I glue this piece into the spar. For more detailed pictures that mostly explain this process, look ahead to the leading edge construction.
Ok then. The plan indicates that the leading edge should be 1523mm long (including end caps). I'm not sure if my leading edge will match this exact dimension, but I'll measure and report at the end of this process. The reason I'm not sure if this will be the same is that I will measure the leading edge out on the sail, figure out where my ferrule will be placed and determine how far out I want the tip of the leading edge to extend from the wingtip of the sail. My preference is to have a ferruled leading edge... and if you're using p200 spars as the plan calls for, this will be required since one spar will not span the length of the leading edge.
I start with the upper leading edge. Taking a p200 spar and placing a vinyl end cap on, I thread the spar into the upper portion of the sail through the leading edge cutout. The bottom portion of this spar is left out for the sake of measuring and marking. The first place I mark is the upper leading edge spreader connector location. (I just match the mark I made on the sail and add it to the spar). Make sure the spar is seated as far into the nose as you can so you get accurate measurements.
Next, I thread the lower leading edge spar into the wingtip and out throughout the leading edge cut out... now the upper portion to be left out for measuring. I place it so approx 1.5" sticks out of the wing tip. (remember that there will be some added length when I place the nock on the spar). some of the length will also be take up when the sail is under tension.
Now with both spars in the sail (sort of), I tension the sail as best as I can. I mark the upper spar where the lower one meets. My preference is to leave the lower spar at full length. This makes it easier to replace if you break the lower spar. Some kites can't manage this due to where the yo-yo stoppers or leading edge connectors sit, but with the B'zar 2011 it works fine to have a full length lower spreader. Not shown in the pictures, but I also make a mark where the lower leading edge connector will sit while the spar is in the sail (as I did for the upper portion)
With the lower leading edge spar, I make a small arrow pointing to the nose where I've made the leading edge connector mark. This way I know which way to thread the spar in the future.
Once I'm done with one leading edge, I use those spars to mark the spars for the other side. I butt the spars up against a stop and copy the measurements to the opposite leading edge spars. This requires a little bit of faith in myself that I built the sail symmetrically... but I've had good luck in the past so I have no reason not to trust myself. If you're worried, repeat the steps at the beginning of this entry for both leading edges.
Now to building the upper leading edge. I have already marked where the spar needs to be cut by comparing where the lower leading edge meets up with the upper leading edge. I then take the spar out of the sail, mark the spar for the opposite leading edge, and then tape at the mark (tape on the portion of the spar that will be kept... this protects the spar and is a reminder of which side of the mark to cut on. When I cut these spars, I leave a small amount (approx 1mm) that will be sanded flush while the tape is still on the spar.
Sorry I don't have a pic of the taped spar sanded to the exact length; your imagination should suffice. After sanding the spar to be even with the tape, I remove the tape and sand a taper to the end of the spar... this will help keep it from snagging or wearing prematurely on the inside of the leading edge.
For the leading edge ferrule, I use a 3" portion of solid .240 carbon. I sand a taper on the end of the ferrule that will slide in and out of the lower leading edge. I then tape this end of the ferrule so that the tape indicates the middle of the ferrule. This way, when I glue the spar, when the tape is removed, any excess glue will peal off.
I also reapply tape to the upper leading edge spar prior to gluing. again, this way when I take the tape off it will remove any excess glue. Here is a picture of the ferrule glued into the upper leading edge, prior to tape removal.
And here is a picture of the finished upper leading edge at the ferruled end. Note how the ferrule and the spar itself are tapered to reduce wear on the leading edge and to help guide the lower leading edge spar into place.
To make the standoffs, I cut 4x 3mm spars to 265mm (the plan calls for 2 at this length and 2 shorter ones... I shorten them later). Once I have the standoffs cut to length, I pound the carbon into the sail side standoff connector.
The reason for cutting all of them to 265mm is that there is inevitably some variance when cutting... I pick the two that are closest to the desired length and finish the end by sanding it down to a taper.
Because I use the exel standoff to spreader connectors, I do not put a vinyl end cap on my standoffs. If you use APA standoff connectors, you will want to use a vinyl end cap on each connector. This will increase the length by a few millimeters, so do some trial and error measuring before (or if) you glue the end caps in place to make sure you have the appropriate length.
The two standoffs that were slightly off of their measurement go back in the hobby vice and I measure as accurately as I can and mark the 261mm mark for the shorter length. Note that the cut should be just to the right of the mark in the next picture to get the proper length. The mark will be sanded off when the end of the spar is tapered.
Here is a pic of all the ends of the standoffs... note how small the difference in length is. Don't get them confused when you attach to the sail. The shorter spar goes to the outside of the long one.
Another 10 minute task that needs to be completed is the wing tip nocks. I use HQ style nocks. They need to be fitted to a .240" ferrule so they will slide into the leading edge spar. I put a solid carbon spar in my vice (gently... remember that a vice can damage a carbon spar; even a solid one). I place the nock on the spar and then measure 1.5" from the base of the nock to where I will cut. See the picture. I cut the spar to this length and then repeat.
Also needing to be done is making leading edge connector stoppers. Many people use 'c' clips. I prefer to cut the end of a vinyl end cap off and use the remaining tube. it is a little cleaner than the 'c' clip and is easy to glue. The only downside to using the vinyl is that once glued, it is harder to get off the spar... so measure twice and glue once. I actually cut 6 of these little homemade connector stoppers, as there will be one fore each leading edge connector, and one on the top and bottom of the center T.
And here's just a little teaser of the almost finished kite (no bridle yet, but a good idea of how it will look at the end).
Ok, a couple of quick things. I've been holding off on some of the documentation, as I was waiting to hear from Ken McNeill of Blue Moon Kites. I have adapted and used a number of Ken's techniques in my own kite making and I wanted his permission before I disclosed/showed how some of the particular traits of the kite. He has given his "ok" so I will continue with the documentation.
First, and probably next in the process, is preparation of the leading edge APA connectors. On many of my kites, I use the TAPA connectors for the upper spreader in order to stream line the leading edge (smaller connector = smoother covered edge). The TAPA work great with a 5mm upper spreader. For larger kites that utilize a 6mm upper spreader, a full size APA works better to hold the spreader in place without it popping out. Ken uses full size APA connectors, but modifies the outside edge of the connector to lower the leading edge profile. it is a minimal affect on the part, but results in a significantly smoother leading edge on the kite... see the modified part on the left and the original on the right.
To accomplish this, I load a 6mm spar with two of Ken's brass weights and the connector (as seen in the picture). Then, using a bench grinder I bring the profile of the connector down to match the diameter of the weights (being careful to avoid grinding the weights down, as I will be using them for the kite). Ken had no problem sharing this technique with me and I now customize all of my full size APA connectors in this way. Be careful with the grinder, as it will take off material very fast (including skin and bone if you should accidentally touch the stone while it is spinning... please take safety into consideration when doing this yourself).
It is important to use the small rest on the grinder to support the connector while you shape it... so shape one side, then flip and shape the other. If you have a Blue Moon kite, take a look at the connectors to get and idea of how far around you should shape the part... notice that I avoid taking any material off of the area where the spreader is placed. You only need to take material off the leading edge side to effect he profile of the covered leading edge.
Earlier I mentioned that I would measure my leading edges to see how close they came to the 1523mm dictated in the plan... with the technique I use to measure and cut my leading edge, the length of my end product = 1521mm (with endcaps). So even though I altered the nose pattern, my frame is almost identical to the plan. And even more importantly, my spine is 842mm... exactly the same as the plan calls for.
Ok, time to put some of these spars in the kite. Before you put the spars in the leading edge, make sure you glue the leading edge connector stops in place. I test fit everything first, then take it all back out and glue it up when I know the marks are in the right place (this is a pain, but I've regretted not doing it in the past... also, I discourage you from gluing things in place when they are in the sail; I've glued the sail to the spar before and this is not something that will make you happy).
Once the stops are glued in place, slide the connector onto the nose end of the upper and leading edges. Not pictured here, but make sure you also place your vinyl end cap on the upper spar before you place it in the kite. Here is the lower spreader prepped to go in after the upper leading edge.
So, note that you should put the upper leading edge in first, but I was so exited to get the spar in the kite I forgot to take pictures. It is the same process as the lower leading edge. First, slide the spar into the leading edge cutout going toward the wing tip. then, as you insert into the leading edge toward the nose, work the APA connector down towards the stopper you glued on. Work the spar toward the nose and push the connector further along. Alternate sliding the spar, then the connector until the spar is seated completely in the nose and the connector is butted up against the stopper. If you want to see this done to perfection, check out Jest of Eve media section to watch video of the process (he uses a little bit of soapy water to help the connectors slide easier... not a bad idea for tight fitting parts).
Once in place, it should look like this; notice how low the profile is on the leading edge covers. this is due to the custom APA connectors, and to the fact that I have a large cutout that allows for a more gradual transition going over the connector.
After putting in the upper leading edge, repeat the process with the lower leading edge and then on the opposite side of the kite.
Leading edge tensioning: I use dacron cord... 1000 ft of it is only 13 dollars and will last until the end of time if this is all you use it for. I start with an exuberant amount because it is easier to tie when it is long and I don't care about cutting of 6 or 7 inches when I'm done. So take about a forearms length of cord off the spool... cut it and melt the end with a lighter to prevent fraying. Fold over 2" worth and tie a loop.
It's hard to see, but this is a picture of the loose end of the knot melted down.
Thread the loop through the first hole (closest to the wingtip). Thread from the front of the kite to the back. only the loop has to go through, not the knot.
Now, take the other end of the cord and thread it through the hole in the nock (not the slot) and note the orientation for the nock... thread from the large opening, out through the small.
Now, on the back side of the sail, thread the loose end of the cord through the loop as shown, towards the nose.
At this point, you can put some tension on the leading edge. Pull everything tight and it will stay (to a point). This picture is of the back of the sail, after putting some tension on the cord.
Next, thread the loose end through the second hole... from the back of the sail to the front. (a little out of focus in this picture, but you get the idea I hope).
Now, bring the loose end around and into the slot in the end nock. While pulling it tight, mark a spot with a metallic sharpie where the knot will be tied. A significant amount of pull should be used as the line will let a minuscule amount of tension off when the knot backs into the slot.
At the mark, tie 2 or 3 overhand knots on top of one another (so it won't slide back through the slot). Then cut the cord so you have about 5" of slack that will act as an easy to grab/hold extension (don't worry, it won't show in the end). Be sure to melt the end to avoid fraying (not shown).
Then, with the sail tensioned, slide the loose cord end up into the leading edge side of the sail.
When all is packaged nicely, cover with a vinyl end cap.
For the spine weight system, I have made use of Ken McNeill's system (so I can conveniently use his 5 gram weights). He has given me permission to show this in the thread, so hear it is.
It's pretty straight forward/simple, and anyone with a Blue Moon Kite could probably figure it out. To start, take a 6" length of .240 pultruded carbon and finish the ends like the ferrules in the leading edge. Secondly, cut a 1cm portion from a spar like your spine or other carbon tube (I had some left over P2x from an old build that I chose, but any sky shark tube with .240 inner diameter should do the trick). Glue it so you have approx 1.75 inches (this 1 cm sleeve portion acts as a stopper for the spine, so use significant amounts of glue and wipe off any access with a rag... be fast). Here is the picture of the finished tail end of the spine with loose parts.
Using the APA connector and the 'o' ring, place the weights on the spine (you can probably get brass tubes/bushings and grind them down to size, but I already have a gaggle of these weights from the stack of blue moon kites I'm acquiring over the last couple of years). I like Ken's weights because they are 5 grams each. The plan calls for 20 grams, so use 4 weights. I'm starting with 10 grams just to try it out. Also remember that my nose is shaped differently than the plan and might alter how much weight is preferred. Everyone may have their own preference so use what you like.
Keep in mind that you will have to shorten your spine tube to accommodate this piece. Shorten the spine by the length measured from the base of the APA connector to the upper end of the carbon sleeve... in this picture it is 4 and 5/8 inch. I actually placed the tail portion of the spine in the velcro strap and the spine tube in the nose and measure out the length I have to cut off the spine in that manor... just like how I measure out the leading edge spars. Any way will work fine, just remember to measure twice, cut once.
Here is the spine in place. Note that there is enough space for approx 6 weights. There is no reason you couldn't build the tail piece longer, but I don't see a need to have more than 25 grams. If you need more, you can get some solid brass rods from a hobby shop that can be glued inside the tail piece.
Lets talk about some knots. There are 4 basic knots I use to tie up a bridle. (I have also opted to sew my bridles, but for this build I'll be covering what it takes to tie the entire thing). The 4 knots are...
1. overhand knot
2. larks head
3. prusik knot
4. sheet bend (also called becket bend)
Keep in mind that for this short series on knots, I've posted picture of two different ropes for purpose of clarity. Neither of these are bridle line. It is hard to describe the steps of tying knots without covering basic terminology like "bight, working end, elbow, standing part etc" . I have no intention of teaching these terms since these are pretty simple knots. My limited dialogue is actually not terribly important; just follow the pictures. If more instruction is needed please feel free to view any of the numerous youtube videos available for most of these knots.
Almost everyone knows how to tie an overhand knot. I use this knot mostly to form loops and at marked adjustment points for bridle fine tuning. Something I like to emphasize is when forming a loop, or any time you tie an overhand knot with two portions of bridle line, is that the components stay neat and don't cross over each other within the knot.
1. To tie and overhand loop, fold a measured portion of the line back on itself:
Then loop this portion around itself:
Bring the folded end through the loop:
Tighten the knot as close to the end of the folded back portion as able:
Note how tidy this is. I am particular about making knots look as even as possible for consistent measuring and strength. (a poorly tied knot is a weak knot).
2. Lark's head knots are hitches... to connect a leg to the attachment point (also used to attach flying lines to the bridle). A lark's head will slide, so needs a stopper knot to keep the hitch in place (such as an overhand knot!) and from sliding out of position. To tie a lark's head (for this application), start with the overhand loop (make sure the loop is appropriately large... I'll cover this later, but I usually fold back a 10cm length in order to tie my loops; which result in a final loop size of approx 8.5cm).
Fold the loop back on itself, creating two smaller loops side by side:
Thread loops over the portion that you are attaching to.
Tighten the knot so that it is neat... it should look like this without lines crossing in an awkward manor.
3. A prusik knot is like a fancy lark's head... and can be "locked" into position to prevent sliding. I use this knot to connect the upper/outer leg portion to the inner leg/turbo portion... more detail on this later.
Note that the way I'm showing to tie this knot requires that both ends of the bridle are free at this time... as one end will pass back through the loop we need.
Again, start with a loop in the rope. Place the loop under the portion to be tied around.
Pass the opposite end of the line through the loop, around the static line you are attaching this hitch to, then neaten up the knot by pulling it up to look like the second picture below. Note that at this point, a lark's head has been formed (loosely).
Now bring the loose end of the line around again and pass it through the loop a second time... like a double lark's head.
Pull the slack of the line through the knot and neaten it up. The final knot should look like this (this would be the "unlocked" form of this knot that can slide like a lark's head:
To lock the knot in place so that it won't slide, pull the ends back so that the loops in the knots are reversed to look like this:
In the locked variation of this knot, it will not slide either direction.
4. The becket's bend (commonly referred to as a sheet bend) is the hitch I use to attach the activator to the lower leg. This is a hitch that will use minimal amount of line to tie a secure knot. Notes about the pictures, when tying this with large rope, it is crucial to have a length of rope (the loose end) remaining outside of the hitch... with the bridle line, I have a minimal amount of slack and I melt the slack up to the knot to clean it up. The melted end of the bridle will keep it from unraveling.
First, form a bend in the line you are attaching to (the white rope in this case). Bring the loose end of the red line up and through the bend as pictured here:
Bring the open/loose end of the knot around the back of the static line as pictured:
Now, as the loose line passes back in front of the static bend, thread it under itself and out to form this figure:
Now, snug up the knot to form the completed hitch.
The knot will stay in place, even when the original bent portion of static line is stretched out again and results in a hitch that uses up a minimal amount of length in the leg of the bridle:
Now, let's make the bridle! The first thing I accomplish when I tie up a bridle is to make 4 identical leaders that will be the attachment points at the leading edge. I make these with 3 knots that are approximately 1.5cm apart. For this kite, I've used white, 150lb bridle line.
Cut off a significant portion of the line... 75cm should do the trick, but I like to tie up a test lead before I cut the line. (I leave myself way more than enough so I can cut off the extra).
Fold the strand in half. I don't always use a double thickness lead, but for this kite I decided to go for extra heavy duty.
Then tie a knot leaving a loop of 8cm. (use an overhand knot as discussed above). The knot will be the first tie point for the bridle leg so be accurate with your loop on all 4 leads.
Now tie 2 more overhand knots in the lead 1.5cm past the first, and then 1.5cm past the second. The exact position of the knots will be important later, as the length of the lead will need to be subtracted from the plan's given length for each leg. My intent is for the bridle legs to equal the length in the plan when positioned on the middle knot. This will give me one longer and one shorter length to play with when I start to fly the kite.
Now tie up 3 more leads that are exactly like this one. To attach the lead to the frame, place the loop behind the leading edge fitting (I've made up a model leading edge without the sail for demonstration). When the sail is attached, it's easier to thread the loop above or below the fitting and then move it into position). Once threaded behind the fitting, bring the loop around the spreader connector portion as pictured in the second photo here:
In the loop portion that is now in front of the spreader attachment point, form a lark's head:
Now bring the knotted portion of the lead back through the larks head toward the middle of the kite. The reason the original loop was made at 8cm is because this is about as small as I could make it and still get the lead tied to the frame in this fashion!
With all the knots threaded through the lark's head, tight up the knot so that it is neat. Repeat this at all 4 leading edge connectors.
The center T attachment leads are different than the leading edge. I start by making one length of heavy bridle line... I mark what will be the center, and tie 3 overhand knots at each end that will serve as the adjustment points. I did not calculate a specific length for this, other than a bit of trial and error to make sure I could have enough length to tie the attachment lead to the center T in the way I wanted. I started with this:
Note that the center is marked with a Sharpie and that I have rigged up a demo spine for the purpose of this documentation.
Start by making a loose larks head knot with the center of the lead where you can see it like so:
The larks head knot will sit on the top of the center T on the front side of the kite; bear with me. Note also that the individual ends of the lead are split by the spine at this point... one on each side.
Starting with one lead, it will come past the side of the T piece, around the back of the spine, and back under the front of the T (to return to where you started).
Thread the first lead through the Larks head as pictured... it will end up pointing in to the opposite side of where you started.
Through this process, make sure you maintain the position of your center mark. This is important for symmetry at the end of this processes.
Repeat the wrapping with the second lead in the same manor (on the other side of the spine). It should thread through in the opposite direction of the first half.
Once both leads have been threaded through the larks head, tighten up the knot so that the sides remain equal in length. The end should look like this.
The end, pictured again here has knots placed at 3.5cm, 5cm and 6.5cm. These measurements are important, as they will be the adjustment points for the inner leg of the bridle. I will measure the bridle to be at the dimensions the plan calls for when it rests on the middle knot... giving me 1.5cm of adjustment in either direction. Remember that the larks head is on the top of the center T as the plans have called for. Many kites have the inner leg attachment below the center T, so make sure you double check the orientation to match the plans.
When preparing to build the bridle, it's important to make a few decisions. Typically, I like to sew the loops in my bridle. The reason for this is the ease of measuring... the length of bridle line is not shortened by tying nots. For the B'zar build, I've decided to tie up the bridle using the knots discussed in previous posts. To start, developing a standard for your bridles is important for repeatability and accuracy. For the ends of each leg of the bridle, I always make a loop with an overhand knot. I fold over 10cm of bridle and tie the overhand knot as close to the end as possible (for the largest possible loop with a 10cm fold over). As I mentioned, I fold over 10cm, but I mark the line at 12cm in order to measure how much length is lost to knots.
After I tie the knot, I see how far the original mark has moved... in this case I have lost approx 1.5cm of length by tying the knot. (note that I have not cut off any bridle line from my spool... I will do this once I have figured out how long to make the first portion).
Now, the final requirement to calculate your length is to tie a larks head knot around a test lead and measure how much is lost from the original mark. The final amount lost from the original length (at the fold, before any knots are tied) is 3cm... see that the mark is at 9cm.
If this is getting complicated, hold on. I can make it harder yet.
Now, we know that from the point we fold over (a 10cm portion) to the final amount lost in length is 3 cm. That is only important for figuring out the length of the actual bridle legs. Remember that the leads also need to be subtracted from the length of the leg. As I intend on using the middle knot of each attachment lead for the default position (as dictated in the plan), I will calculate that the there will need to be 3.5cm subtracted from the length on the plan...
So now, to make it even worse, I make my outhauls out of one length of brilde line... upper leg and outer leg = one piece.
Because I wanted a visual for what I'm going to explain, I made up a quick color coded pic of the bridle. These are the pieces as I have built my bridle for this B'zar:
1: orange = connection points/frame leaders
2: purple = turbo and pigtail
3: red = inhaul/ inner leg
4: grey = activator
5: green = outer and upper legs (upper and lower outhaul). This is one piece.
I've delayed working on this because I was unhappy with the photographs of my bridle build. I'm going to completely rebuild my bridle (first one will be saved for a future B'zar build) for the purpose of better documentation. To go along with this, I'm going to be building a new bridle board that will be beneficial for future builds of many different kites.
My original intent was to show how I figure the dimensions for a bridle, how much length is lost to knots, etc. (as started in the previous post). While this information is helpful, what I'm going for now is a method in which less math is involved and more building is taking place. To do this, I'm building a bridle board of my own design.
Bridle boards tend to be concoctions of a flat surface with various markings/indications for measurements related to the particular kite being built. Mine is no exception, but I've designed a board that will not only be reusable for future B'zar builds, but for other kite plans as well. Here is a simple sketchup design that depicts what I'll be using. Note that my board is already built and documentation is lagging, but this will give you an idea. The thought behind it is that I will have an over engineered structure that will have a tie off point built in. Then, I'll use removable templates for all of my different kites. Each template will get labeled appropriately, then I can easily store just the templates out of the way. So, enough jabbering, here is the visual idea:
It is not a complicated design, and if you decide to build one, it can be done any number of ways to accomplish the same thing; so detailed documentation of the bridle board build will not be presented here.
With this bridle board I've built, it's still important to know how much length is lost to tying an overhand loop and lark's heads and prusik knots, so I've left the previous post in about measuring the loss. Less math will be involved now, as we won't have to subtract the leading edge attachment leads from our final length... you'll see.
Here is the bridle board in all of it's glory. It's constructed out of 3 layers of 1/2 inch MDF. I built it larger than needed so that is will have some heft to it. In the past, boards I've used for this purpose have slid around and needed to be clamped down; not any more. Note also that the top layer is multiple parts, with a slot that allows me to put a 1x1/2x36" template in place... each unique to the kite I'm building. This allows me to use the same board for future and repeat builds. I've drilled and placed a scrap piece of a p200 spar and added a center T and an APA leading edge connectors along with replicated leads for measuring. (I do realize that I may use different spars in the future for leading edges, but the difference in diameter is negligible)
For the template, I've used a measuring rule and marked (and labels with lengths) the measurements for the B'zar bridle. Note that they are in different colors. I've written a key for the colors directly on the bridle board that will be consistent with future builds. Only the measurements will change.
At the top of my template, I've placed a 10cm mark. I almost always make my loops by folding back a 10cm length at the end of the bridle line and tying an overhand knot. Each portion of the bridle starts this way. something to note is the red mark... it will become the end of the line once folded and tied. Sometimes I do not mark the first one, I just hold my thumb nail at the correct spot and make a fold. The bridle line is pretty easy to hold a folded point while tying it off.
Now, these are the beginning steps for every portion of the build (I realize I'm mentioning this twice, but repetition helps with understanding). This particular portion I'm picturing happen to be the Upper leg and the outer leg (I'm not going to cover much terminology here... I assume everyone will know that this could also be referred to as the lower and upper outhauls). I almost always build the upper and outer legs as one portion of line.
Once the first loop is tied, I attach the line to the jig. Remember, I want the middle knot on the attachment lead to be where the bridle equals the plan dimensions. This way, I can experiment with making the legs longer or shorter. So, loop is now attached to the middle knot on the leading edge attachment point:
This is the upper leg portion, so I bring the line taught and make a mark at the 525mm mark (the mark is red, but this doesn't matter).
Now, not pictured terribly well here, I take the line off the attachment portion of the jig, flip it around, line the red mark up with the 545mm mark (length for the outer leg) and I clamp the original looped end at the end of the bridle board so that the mark still lines up with the 545mm mark when taught.
Now, at the APA end of the jig, I tie a larks head so that there is enough tension on the line to hold this portion up (remember it is clamped at the other end). This takes a little practice, but can be done fairly easy. I then mark the line at the center of the knot (see picture). Remember though, this is not the mark where you will fold to tie your loop! If you remember previously, you have to add 1.5cm past this mark to account for the line used in the overhand knot.
I accidentally skipped a step in the photos. The important thing to note is that you need to loosen the line by 1.5cm and make another mark to compensate for the knot that will be tied to form the loop. at that second line (looser, or closer to the spool; yes the spool is still attached), make a fold and measure out 10 more centimeters. Make a final mark at the end.
In this picture, you can see that I've added a note to the template to loosen (my short version "loose) the line by 1.5cm for the leading edge loop knots. I then made the mark at what will be the final knot. Remember, the spool is still attached and sitting just to the upper right of this photo.
Now, with the line folded over at 1.5cm longer than the original red mark, and tied off at the indicated place of 10cm, you can cut the line from the spool. I cut about 5mm away from the knot, and melt it back. (melted portion not pictured).
Now, I've one Upper and Outer leg assembly. Repeat this portion. (remember, your bridle is identical side to side, so you have to do two of everything).
Once you have two of these, lay them out and be sure they are the same length. fold them at the mark you made to indicate the separation between upper and outer legs (which will also be the attachment point for the turbo portion of the bridle). The upper and outer legs are only a few centimeters different, it should be reflected at this point though.
Now time to move on to the turbo, inner leg and activator portions.
The activator is constructed in almost the same way, but the biggest thing to remember is this: My activator will not rest on the middle knot of the LE attachment point. I'll be using the knot closest to the spar. That being said, I may also play around with adjusting the activator... the reason for using the closest knot is that I only only foresee wanting to lengthen the activator (I know this from my first bridle build, as the activator does put quite a lot of influence on the inner leg with the dimensions the plan calls for).
So, start with a 10cm overhand loop. Then attach to the jig. (also note that in this picture, I added the 1.5cm mark at the top of the template).
Now, I bring the line taught and make a mark at the 316mm spot on the template, indicating what needs to be the final length of the activator.
With this portion, I'm not attaching to a spar... it will attach to the inner leg with a prusik knot (or a sheet bend, but I'm planning for a prusik for easier adjustability). The previous method of tying the knot, marking the center and adding 1.5cm can work, but you'll need and extra hand to hold the line taught. What I've done is figured out that a prusik knot also takes 1.5cm of extra length. So I added one more mark on the template and a note that states "loose 3cm for prusik knot" that is to indicate that I need to loosen the line by 3cm. so, I've added another mark to the line 3cm closer to the spool that will be the spot I fold over.
Then, I finish the piece the same as the first... measure out 10cm, make a mark, tie the overhand knot for the loop and cut from the spool, melting back the 5mm portion left past the knot when cutting. Then repeat all the steps in this post for your second activator. Lay them out and make sure they are the same.
Now I'll build the turbo/leader portion of the bridle (there is no need to go in a particular order... none of theses pieces should be attached to the kite yet).
Start again by tying a 10cm overhand loop. (didn't I mention that EVERY portion of this bridle build starts this way?). Now, I like to have long leaders. The hope is that it will save my flying line from wearing out. This portion of the bridle is easier to replace than trying to even up my flying lines. So, I just put the loop around the spar on the jig and make a mark at the end of the 36" template (the only measurement in this bridle that isn't done in metric). After making the mark, I cut the line about 10cm past the mark. Then tie an overhand knot so the mark is on the side closes to the kite. Finally cut the extra and melt the line back to the knot (not pictured until the next step).
Before I tie in the knot that will distinguish the length of the turbo, I make my second leader using the same steps. However, when I get to the last step of tying the overhand knot, I compare the two portions to make sure the overhand knot really ends in the same place. Even if your mark is accurate, because this is where the flying lines attach, the overhand knots have to be in exactly the same spot. So, loop both leaders on the spar and bring them taught. Then, when you tie the overhand knot in the second piece, just make sure it ends up in exactly the same spot.
Seen here is the comparison... first completed piece on top with the extra cut off and melted back to the knot. Second piece tied in exactly the same spot still waiting for the access to be trimmed off.
Now, going back to the first piece. To form the turbo, an additional overhand knot is tied in the end with the loop. So, place the loop directly on the template and make a mark at 25mm as shown, I only make one side of the loop at this point.
The turbo will attach to the upper and outer legs by use of a prusik knot. Remember that this takes 1.5cm of extra line. Now, I made a mistake in my documentation here. My photo shows the final red marks (across both portions of the loop) at this final measurement. This was a mistake, as I thought the inner leg would attach to the turbo at the inside of the knot. If that were the case, then this photo would be correct. Instead, the inner leg must attach to the OUTSIDE of the knot... away from the kite. so, what I should have done is added the additional 1.5 cm (3cm total) from the first red mark. Then, tie the overhand knot on what would be the left of the mark in this photo. sorry for the mishap. Anyway, here is the picture showing the marks in the wrong place.
As you can see here, I've completed both Turbo/Lead portions and am comparing them to make sure they are the same.
At this point, I'm ready to move on to the construction of the inner leg (and the last piece before attaching it all the kite!).
The inner leg starts the same way with a 10cm loop, but instead needs to be attached to the center T portion of the jig. Then, complete exactly like the activator, only using the 645mm mark on the template.
While still attached to the jig, I make a mark indicating where the activator will attach at 180mm.
Then finish just like you did the activator (I won't use a prusik knot... but the larks head I'll use to attach the inner leg to the turbo has to go around two line thicknesses, so it's roughly the same). Add 3cm of length past the red mark at 645mm. Fold back 10cm from this mark, tie off and cut away from the spool. Repeat steps in this post to create your second inner leg and compare them to make sure they are the same length.
Now, lets get this thing on the kite. There is a way of doing this that is easier, so follow the steps here. Please note that the sheet bend knot you learned earlier will not be used unless future flying deems it necessary (the only point of concern would be where the activator attaches to the inner leg. This may require a sheet bend if the prusik I am using now slips. Only flying the kite will tell me for sure).
Anyway, attach the upper leg and the inner leg to the kite in their respective places. (on the middle knot of the LE attachment and the middle knot on the center T). The pictures will show one half at a time, as the resolution won't be high enough to show both sides at once. Just do everything symmetrically.
Attach the activator to the inner leg at the red mark with a prusik knot. The red mark is in the middle of the knot (hard to see in picture). The other end of the activator should not be attached to the kite yet... I find it easier to tie the prusik when I can loop the free end back through the knot.
Then lock the pusik so it won't slide along the inner leg (lock by pulling both portions if inner leg away from the activator and folding the knot over itself). Because the inner leg will have tension on it, this may come undone during flight and require it to be converted to a sheet bend... but for now I'm leaving it as is.
Now, you can attach the free end of the activator to the kite by forming a lark's head and threading the outer leg, upper leg and attachment lead through the lark's head. (if you already attached the outer leg, shame on you for not following directions). See how much the activator affects the inner leg? I have measured this multiple times to be sure it is as the plan indicates. Remember that I built the activator to be attached to the knot closest to the spar (shown in second pic on the right side of the kite).
Now, before moving on, put tension on the inner leg towards the nose of the kite. Both activators should be at the same hight.
Now, attach the turbo to the upper and outer legs at the red mark with a prusik knot (the same way the activator is attached to the inner leg). With the turbo attached to the upper and outer legs, attach the inner leg to the turbo with a lark's head... below the knot in the middle of the loop; as pictured here.
Now, attach the outer leg to the kite at the middle knot on the attachment lead.
Make sure both sides are all tied up to the kite and look symmetrical. Here is a shot of the left side under tension. If yours doesn't look like this, review the plan, double check again, then triple check. If it still doesn't look like this when all of the mistakes are accounted for, please review my writings and let me know what I did wrong!
Now, finally, attach your yo-yo stoppers. I use APA or exel fittings with a zip tie. Punch a hole in the leading edge where marked from the plan (silver mark, barely noticeable in this picture) and attach to each leading edge. No problem.
The kite is now flyable. Thanks for reading along. I'm sure you will enjoy flying this kite!
If you want to build other kites or get more info on building, join us at the Gone With The Wind forum!
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