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Kite Building

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At last some vid

Firstly a big thanks to ExtremeKites and especially Joel for sorting my prize out.  Yes it was a real competition :Thumbs-up-smaller:

Secondly apologies for the video, it's the first time I've had chance to get my phone hooked up to it and get some footage, so here it is unedited but it proves the kite does fly, wind was very lumpy and rain very imminent:

littleHammer.mp4

littleHammer.mp4

Building is a journey

With a Z-Bridle fitted to my new 3m, I've been itching for more flying, a business trip to Irvine, west coast of Scotland, so in to my hand luggage went the kite, I was expecting to be asked what was in my luggage but nothing! Straight through it went.  First evening good wind coming nearly off the sea, roughly 12mph, first attempt, kite leapt up and straight back down, second time, up around 12ft then a reverse death spin, WTF still too much brake? Or have I created a new "Damien". Moved the brakes a bit more, up she went, still short of the zenith but oh lordy did it pull, virtually no tip collapse, with a coastal wind everything is so much easier, pulling 20-30ft scuds with ease, down loops making loads of power. While walking back I was thinking maybe one more mod to the brakes, to keep the wing tips inflated, it's holding the kite back.  So an evening of tinkering.

Second evening, laid kite out, NO WIND! Just the odd rustle of neck hair, tried a few catch the slight breeze and walk back, no more reversing, no wing tip folding just sliding down when there was just too little wind, by this time the tide was on it's way in and the wind started to pick-up a steady 6-8mph, this time the difference at the zenith between where it did park and now does is halved.  Feeling much better, power still piles on with a loop, all looking good.

Weather and work were against me for the next evening, like a scratch you can't reach, I still think there is a touch more to get in terms of speed / window, so I have partially reduced the AoA, which will drop the power a touch and give more speed / window, well that's the theory anyway.  Now to go back to watching trees for the next opportunity to fly.

 

Damien: Was a 3m HA NPW9 I built a while back , it flew like a stunt kite, had less window and when I tried it in the buggy was a nightmare, fully powered it just wanted to reverse given the slightest opportunity.  I tried all sorts but could not crack it.  Thinking how that flew compared to my new 3m they are poles apart, the thing that really keeps striking me is the power it generates, although I could pull longs scuds sending it up was not creating heaps of lift, but nor was there anywhere in the window to rest, even parked at the top it was still pulling. 

Here is Damien:NPW-HA-3.JPG

 

I you're thinking of making a 3m HA NPW or less for traction this is me trying to buggy :D

Damien Vid

 

      

I mentioned another story in my last entry, some of you may already have seen a post I did on another forum a few years back but thought I'd re-tell for those who did not see it.

I used a field to buggy in which is pretty much a rectangle, over 100m wide and about 220m long 7.4 acres, on the rhs and top edge there are erm power lines (marked in red).  Starting flat at the bottom and rising up to a flat at the top.

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Okay scene set, now for the weather, it was blowing @ 20mph and I decided that it was time for me and my trusty 5m NPW to do some serious buggying.  Off I set, ran down the field in the buggy with no kite up, kite out, away we go OMG I took-off like being fired out of a canon, up to the top of the rise and back down, did this a few times, I was absolutely buzzing, stopped at the bottom, dropped the kite for a breather, I had a grin like "here's Johnny".  

Ready for next run, stake out, "Pirate, November Papa Whiskey 21 read for take-off".....

Revvin' up your engine
Listen to her howlin' roar
Metal under tension
Beggin' you to touch and go

Highway to the Danger Zone
Ride into the Danger Zone

Brakes off, whoosh, crest of hill coming up fast, ready to turn, now I'm in a surreal bubble time is slowing down, I've stopped and there is no noise, I'm mid turn and I have no kite in my hands, I look in utter disbelieve as there in front of me is my kite climbing still inflated, with two handles along for the ride.  I know get an incredibly sick feeling, I can see the kite approaching the power lines running across the top of the field, kite was too high to drop, so I decided to will it to go higher "GO ON!", like a plane's tail hook the lines caught the first power line, the handles swung under and up over the other parallel power line and continued a full arc, and back over the first, "phew that wasn't too bad", kite now powered up more, the death grip on the power lines tightened and the lines started a journey towards each other, I looked on utterly mesmerised and helpless, next a massive flash and CRACK. Oh holly sh!t.  As if things could not get any worse, I'm now out of the buggy and doing the mother of all walks of shame, the kite has now luffed and fallen across the power lines which run up the side of the field and somehow has wrapped round the two power lines, nearing the house heart thumping I can hear the house alarms going off, my wife is at the back door taking to our neighbour, "we have no power" she says, she sees the look on my face, "Oh please don't tell me it was you", I drop my head even more in shame and that's all she needed for confirmation, as in the distance another load CRACK, my kite had succeeded with it's grip on the other lines.

After placing the call to the power ppl, a posy of land rovers appeared, I walked them to the crime scene, out comes a plastic pole with a saw on the end, and he started to cut the kite lines free first, and like a gift from god my handles dropped back to earth, which I deftly picked up (£25 saved). Next the kite, he was going to go at it like Freddy Kruger, "no hang on, try cutting the lines first", so he set to work cutting the lines, it was still wrapped, I thought it must have melted, then a saw  through the heart of the kite, I was gutted, but a glimmer of hope, it started to unwrap, bit by bit, it fell down, lines checked no damage, nothing had melted!

I now had two handles a sick kite and a good ear bashing for being so foolish, do you realise the dangers blah blah.

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Next morning my wife was setting off for work, "What are we not going to do today?", "Wear my killers" I proudly pronounced, "not fly a kite was what I was hoping for".

And so from the ashes arose "Zombie":

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Fully re-bridled, I decided not to hide the damage and patched it in white to show his scars off. 

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The Devil's place

I'm Working down in Hertfordshire in a large town called Stevenage. I always have a kite or two in the car, so finished work and headed for the local park. Although the park is a good size it's in the middle of a large sprawling town and the wind that goes through it is spawned by the devil himself.

Using my faceometer I reckon the wind was around 16mph, maybe too much but what the he'll let's see how it goes. Left the kite in the bag, run the lines out, stake handles, pulled kite from bag, immediately sprang out and sat there. Picked up the handles, let the brakes off...  three feet up and back down.  s!h!t maybe still too much brake on the Z bridle, give it another go.  Three, four feet, I'm now looking at the handles moving skyward and my new PL killers stretching out in front of me.... please hold, then calm the kite drops back to ground in to the only muddy patch for miles around. I always religiously wear killers, the once I didn't ended up with the electricity ppl being called out and 400 ppl with no power but that is another story.  I managed to skirt around the center of the window, but there really was no place to rest. 1/2hr and my arms are screaming.  Packed up and checked in to my hotel, first job get the kite out to dry, omg it stank, that muddy pool must have been the aftermath of an elephant eating a local curry! So into a nice warm bath it went, the joys of a kite hobby. Now nice and clean and dry.20160316_231538.thumb.jpg.47ddd6a87e0527

Z-Bridle fitted, wind was a bit all over from nothing to around 8mph.

First take-off, no brake input at the handles massive wing collapse, only the middle third of the kite was inflated, the wing tips just hung down.  Pulled the bottom of the handles back and hey presto it jumped in to shape. 

Made a big adjustment at the brake leaders on the kite moving the Z bridle towards the kite by about 10cm

Second take-off ... you guessed it massive back stall, it only just lifted.

Moved the knot away from the kite by 5 cm to split the difference and it's almost there, felt like it's got just a touch too much brake at the moment, didn't make another change due to time, so just did a bit of flying, reckon I'll back it off another 1cm before taking it out again.

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Zooming in on the couple of pics I took confirmed the feeling I got, the D bridles (last set before the TE) are running slightly slack due to the brake pressure but it's not much.  

Z-Bridle

The Z-Bridle, firstly why use it:

Some single skin kites need some brake input to keep the kite inflated, flying without one, you need to hold the handles with your hands below the top power line to keep a power to brake balance. While flying static, you get "in tune" with the kite and start to fly instinctively applying/releasing the brakes without thinking just based on what the kite is doing. Now jump in a buggy or on a board and this can become a pain as your eye is no longer always on the kite.  The other thing is try an NPW style kite on a bar without a Z-bridle and you will have your work cut out! Turn left and the tension is applied to the lhs bridles releasing the rhs and obviously that includes the brake which can cause the rhs to start collapsing.

This is how I make mine, I make it in two separate pieces, I'm sure there is a calculation to work out how big the Z bridle should be, this is a copy of one I made for my 5m2 kite and works a treat so I guessed it's not going to be far off for my 3m2.  

I'm using 3mm dyneema "static" line which has a breaking load of 370Kg

I start by cutting and burning the ends of 4 pieces of line: Two 128cm long and two 64cm.

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I then mark 27cm down from each end of the long pieces and just one end on the short.

I take the end down to the mark and that give me a 13.5cm long loop, I start sewing the loops 4cm from the end.

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The longer pieces now have a loop on each end, I put the two ends together then move till I have one leg 2cm longer than the other, I run a couple of stitches to hold it in place.

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Double stopper knots are now tied to the ends (checking each pair of lines are the same), the long leg will be the brake line (from knot the diagonal): 

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And now fitted to kite leaders (power lines on the rhs), you can see now releasing the brakes at the handle/bar end will give slack lines but the Z-bridle will maintain some tension to the brake bridle:

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Tuning:

I always tune on handles first, holding your handles now as you would a foil (fingers each side of power line), fully release the brakes:

If the kite doesn't lift or climbs then back stalls: the brake connection needs moving further away from the kite, if there is no more leader, then move the power side closer to the kite.

If the kite lifts and there is some collapse: the brake connection needs moving closer to the kite.

Once you get to the point where it is only slightly doing one or the other, then it only needs a 2mm to 5mm per change. 

First Flight

Weather not ideal, wind gusting 5 to @12mph. Lines on staked down and it looks... tiny in the field.

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Two things I've tried this time: 1 - higher AR, 2 - adjustable wing tips.

How did it fly? It's feisty, from take-off went straight up to just short of the zenith, wind dropped right down and so did the kite, wing tips folded in and it slid out of the sky.  More wind and up it went again, it's fast through the window, really sensitive to input with either just handle or handle/brake.  Did a few figure eights and swooping, sent up to the top, right hand pull and in to a down turn, 3 o'clock the power's raising 4,5 its getting faster and piling the power on, by 7 I'm being pulled forward. Moved my hands under the power lines to keep a little brake tension.

Issues at the moment: Wing tips, I'd kicked them back, but too much, I did shorten them whilst out but think they need more.

Really pleased with the first flight, different kite altogether than the others, didn't overshoot, which surprised me, could be the wind or new location I'd tried, fast and more "snatchy" than the others, feels raw.

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Phase 4 - Pause for thought

All brake bridles and secondary "A" bridles fitted, from this point I'll work my way across all the secondary bridles then build the main cascades up.

Why "Pause for thought" I was thinking as a boy I loved making Airfix kits, tanks, planes and ships, Meccano was another favourite, are we slowly moving away from children making things? Everything today is so easy and electronic gizzmos galore, they don't have to think about much in terms of creating anything or working out how something works. I can see how skills from the past get lost and wonder how many skills "we" will loose.

That said if you are inclined to "do-it-yourself" there are so many resources now on how to do almost anything, but that depends on whether you can be bothered to do it yourself and reap the reward of self satisfaction.

Here is where I'm at, although this is the point I drive my wife mad, "but darling I have to keep it hung up" :D

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Phase 4 - First Bridle

I do all my bridle lines in pairs, same one for each side and check both are the same length.

Firstly I make a loop on the end of the line on the reel, I make the loop 12cm long with 2cm at the end unsewn:

Marked out:

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First loop complete, then I measure the bridle length (plus 12cm for the other loop) and cut:

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First brake secondary pair finished:

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And attached straight on to kite (to prevent any mix-ups!)

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Phase 4 - Bridles

Before I start a bit of background: For my NPW builds I did all the cascade bridling using double slipper knots and double stopper knots, this made the bridling fairly easy and relatively quick, also means any line can be easily adjusted or even replaced, the down side is the knots have a tendency to snag once packed away, I haven't had any issues but care needs to be taken that the kite is fully shaken out and all lines are clear before flying.

Now I know there is a second method, using a fid or piano wire to "feed" the end of the line into the core of the line, pictures and "how-to's" make it look easy, but when you're dealing with 0.6mm line I just can't get me eyes to see that let alone my udder like fingers to try it :D

What I do now for a knot-less bridle is make a loop and sew the lines together (I'll take a pic once started), this means no snagging, but the line with a loop at each end is fixed so no adjustment is available, I start from the kite with a larks head and move outwards to the final collection point larks head at each bridle junction.

This is my line of choice: For Secondaries (closest to the kite) I use 33daN line, for the Primaries I use 49daN rated line.

For this kite I need to make-up 118 lines in total, Making allowances for loops it'll take 39m of primary line and 85m of secondary line.

Bridle1.jpg.af13352b1ba8228f3a9a5ade6485 

Phase 3 - Complete!!!!

One complete kite, hot off the machine:

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Time for a little sewing machine rest.  

Now for a bit a trigonometry, the software package I've been using doesn't cater for the modification I've done to the wing tips, so I need to recalculate the 4 wing tip lines with additional brake to a 5 line cascade no brake.  It's something I did on my 12 and 7m after flying but by trial and error, this time I want to calculate it prior.

Phase 3 - Half way

And so the metamorphosis from flat pieces of material to a kite is half way there! Now no-one can stop the inevitable transformation, soon this monster will live.... mwah ha ha haaaaaa.

Sorry it's the excitement mounting.

I did seriously think about just carrying on adding panel by panel to the end, but, the end panels are the hardest and by the time you get there, you have nearly all the kite at the machine and the fiddliest ( I'm sure that is a word) parts to do, the LE curve is quite tight at the last three panels, so I'm playing it safe and starting from the other end for a final join together at panel 1.

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Phase 3 - Construction

First off, supports, there seems to be a difference of opinion on whether to use them or not, one manufacturer states "No supports" yet later in the blurb it states "Single skin gives a smaller window than a foil, making it easier to use".  The other side of the fence is the de-power leader, quoting "using the latest innovations" and from reports I haven't seen anyone say it's window is much less than a foil.  My opinion is they work, giving a nice stable LE, I liked the idea and the effect of them that I upgraded my NPW quiver with nose supports.  The other builds I've done on this style of kite is they can/will overfly and have a bigger window than my NPWs, at the handles if there is a difference between them and a foil it's not much. 

The supports ready for the construction, one per rib:

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Sewing the panels together with the ribs for me was initially a challenge, the three pieces in flat form at the LE end all have different shapes.  The material needs manipulating then temporarily fixed in-place to sew.  For me pinning just doesn't seem right on rip-stop, I've used super glue, which was closely followed by a tube of super glue remover to clean the kitchen work tops! My weapon of choice now is double side sticky tape, it holds enough to get the first stitch line in, but then needs removing, I did leave it in the first time and the glue on the tape clings to the sewing needle and ends up snagging.

First three pieces in the sewing queue:

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Phase 2 - All prep done

End of my second phase, appliqué design sewn on, all panels hemmed on the TE and LE.  Stats for anyone who is curious:

Flat area 2.99m2  -  Projected 2.45m2

AR 6 - Projected 4.5

Wingspan 4.23m - Projected 3.32m (It's only 30cm shorter than my 5m!)

And this is what it currently looks like before it goes back under the sewing machine for final assembly:

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Phase 2 - The kite

Big smile time, for the white and red it's a matter of tracing the printouts (with the material stretched out) and cutting out, I don't hot-cut these as all the edges will be hemmed.  For the black, I cut around the printout, laid it on top of the material and traced around the edge.  So here we have one half of the wing laid out and the other side piled up ready.  I'd usually plough straight in to the construction now but..... I'm putting an appliqué design on.

wingI.thumb.jpg.5406abefb405146c692bc6fe  

 

I've gone for a black design, firstly I made a template, stuck the paper printout on to card and cut it all out:

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Next job to trace on to the black material and hot cut it all out using my trusty gas soldering iron.

Phase 1 Complete

This is probably my most satisfying moment, when all the ribs are finished, lots of work for something that doesn't look like a kite! From this point on things start to take shape:

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One side's worth of ribs all cut out and the bottom of each "V" hot cut ready to hem.

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The top edge has a roll hem, I insert Dacron tape at the tops and bottom of each triangle to give stability and strength.

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And finally, I've sewn 4mm Dacron sleeving to the hem creating a loop at the top of each triangle.

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Rib background / disclaimer

Before I show how I do the ribs, a bit of a disclaimer, mine is not the definitive method, it is only my interpretation of what works.  I have not found very much on the net which details methods of making ribs, in fact I have found only one, which I used as a basis to upgrade my NPWs.  The way I see a rib (or keel) is to spread the load of the bridle across the kite surface rather than connecting direct to the kite. The downside is the profile is fixed on the rib, so not much leeway to tune the bridles, the upside - less bridle lines and a much smoother kite surface.  

The first method for my NPW involved hot cutting two identical ribs, sandwiching them together with a line sewn between in the top edge, not so bad for an NPW where there are only two needed for each side, the result was a smooth kite surface and 5 bridles instead of 10:

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I then had the opportunity to fly a certain prototype, which was a single skin with ribs, the method used for the ribs was much simpler than I had tried, but looking at the pictures I took whilst flying made me realise the rib was not really working as I thought they should, the skin has stress lines below the bridle attachment indicating the load is not being fully spread across the rib:  

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And so I have arrived at the method I now use, the stronger the wind is, the smoother the kite surface is, this was a one-handed grab a quick pic, which hopefully shows the difference and why my method may look long winded and not one you'd see on a commercial kite, but I think it's worth the extra time:

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Ribs the start

Starting with my printed out plans, and the bit's I need to do the ribs:Rib1.thumb.jpg.226d6f543828c171ab320b9cf

New material laid out and weighted down to keep it taught.  Steady hand and a bit of patience to trace the plans on to the material:

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One side done ready to cut out:

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Now to repeat for the other side and all the ribs are ready to be worked on.

 

Nothing to show yet

In my head the build has started, in reality nothing to show yet, after a recent house move I've put my stash of material (for this build) somewhere very very safe!  In the meantime I've tweaked my wing tip design, printed all the templates (in A3) and stuck them all together.  Done some web surfing and settled on a design to appliqué to the wing (or maybe both sides).  Only problem is the design will be in black, you can't see through the material to trace so it's a matter of cutting the design out and drawing round it on the material, but more of that later..... where the f@@@ is that material?

This is top of the list to run across the mid section of the wing:

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A New Year .... a New Build

As some of you will already know I build my own kites, starting from simple one colour NasaParaWings (which started life with NASA as a re-entry chute) to the new breed of single skin kites which have their roots in the paragliding world.  I've had a long spell from kiting (well for me @ 6months). After building three new style kites 12m, 7m and a 5m which I call the "Hammers", why? Because of the punch they deliver, don't get me wrong they are not snatchy, they are very smooth and progressive.  After spending a lot of time trying to push the limits of NPWs I could not get the window of a foil, that said what I did have was a quiver of very usable and unique kites that I used religiously and enjoyed every minute. Then an internet search lead me to someone who was building single skin paragliders and offered the design software free on-line, the seed was sewn could that be used as a basis for a traction kite?  I jumped in feet first and went for a whooping 12m2 which flew straight off the sewing machine. The 7m and 5m soon followed with changes to wing shape and AR.  The build for this type of kite is much more than the NPW and means I need to amass more brownie points before a build :D

So my plans for the new year is a 3m2 AR6 fixed bridle, plans are printed out, colours decided, now to check out what needs ordering.  I reckon it'll take @7.5m x 1.5m of material and 48m of bridle lines, estimate of time @92hrs

 

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