Search the Community

As I mentioned in another thread, I have a heap of material left over from building 1830 F-arc's. The f-arcs are made from good quality chikara ripstop and it is too good to just throw out, so I decided I needed to put it to good use. I have been playing with Surf Plan for a while now and although I can get a design that looks good, I have no idea if the design will fly or not. Then one day looking threw some old archived websites, I found a link to the surf plan design specs for a 6m p-arc. P-arc (P=parallel) was the original name of the F-arc, but was changed before release because Parc backwards is crap SurfPlan Download P-arc base.sle anyway, I decided it was worth giving it a go since I already had the material. So I got the plans printed out on A0 paper and set to work. first thing I had to do was unpick every seam on the remaining sections of 16m f-arc, which took a lot longer then expected. next came the marking out and cutting. Because I was working with material that had been folded and crushed, rather then off the roll, it was a nightmare getting it to lay flat to trace the outline on to. I had to flatten an then clamp the corners to the table. As well as the outline of each piece surfplan also allows you to add waypoints so everything can be aligned after being cut. I used a hot knife to cut all the pieces out to make it a bit quicker and stop the edges from fraying. i then used double sided tape to stick all the pieces of the top and bottom skin together for sewing. The ribs were too difficult to stick in place, so they were just aligned and stitched as I went. (A walking foot attachment from eBay makes sewing ripstop sooo much easier) The surfplan design didn't have spar pockets, so I made them from some 50mm webbing and stitched them to the end cells. I also added internal front and rear straps of 25mm webbing, similar to the more modern arcs. Like the modern arcs, the rear strap has adjustment for the middle 5 cells and wingtip 5 cells. I also made the front line adjustable at the middle 5 cells, in case the kite was prone to backstall. And the finished product..... flat area: 6m wing span: 6m AR: 6.0 I estimate it took about 100hrs, cost $150 and countless ?

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

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. 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. 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. 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): 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: 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.

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. 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.

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

Now suffering with sewer's back, from being hunched over the sewing machine like Rumpelstiltskin, bar fitting the four leaders as it comes down from it's hanging place, this puppy is ready for a test flight

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"

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 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.

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: First loop complete, then I measure the bridle length (plus 12cm for the other loop) and cut: First brake secondary pair finished: And attached straight on to kite (to prevent any mix-ups!)

One complete kite, hot off the machine: 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.

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.

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: