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Homemade Kite?

kallie.spidahl - 24-8-2015 at 07:39 AM

Hey guys! My first time posting on the forum! I'm hoping to make a homemade single skin kite. I have some kiting and sewing experience but there seems to be hardly ANY information on kite construction- I've scoured the internet! I'm a member on the yahoo foildesign group but it's not very active and folks haven't been very helpful.

Has anybody successfully built a kite using the single skin software below? I know if Surfplan and Foilmaker, but those are for closed cell kites (which I wouldn't mind making someday either).
http://sourceforge.net/projects/singleskin/

Can you help me? I know you need 3/4oz ripstop, mildew resistant thread, but what type of dynema for the bridle exactly? What type of plastic for getting sewn into the cells? How do you assemble the kite? How do you make the bridle attachment points? The software configures the bridle, but it doesn't tell you on the pattern you print out where to place it... What type of knots on the bridle?

I'm determined to have a project for this winter! Any help would be great!

Randy - 24-8-2015 at 10:09 AM

Kallie,

Welcoome to PKF. Ian (who posts as BigE123) has experience making single skin kites and there may be a few others as well. I would love to hear his comments on the program you listed. Building a single skin kite such as you describe is quite a challenge.

Nasa Parawing ("NPW") kites are much more accessible and there are plenty of plans and programs out there that are quite excellent. Kiteplans.org has a number of NASA kite plans listed under 4 line kites. http://www.kiteplans.org/cat_3/sub_34/

You don't really need the 3/4 oz ripstop, and I recall Ian commenting that the really light material is harder to work with an not as sturdy. It doesn't take a lot of sewing skills to make a kite, but starting with the really scarce and expensive ripstop may be too much too soon. I've used a variety of materials from light plastic tarp material to medium weigth (or more) ripstop and built about 20 Nasa kites. Dynema is one of the best bridle materials, but, its expensive and not that easy to work with. Dacron is quite commonly used.

I'm not saying don't use the first class materials, just that it adds a lot of cost to the equation, but is not going to make the difference between a kite that flies and one that doesn't. Rather, understanding the plans and following the instructions are the most key elements in the process, along with the patience to see it to the end.

On my youtube page I have a number of videos of different NPW kites as well as some simpler single skin kites if you would like to see what they look like.

https://www.youtube.com/channel/UC19616vtWS03nWD5zFEt5Fw

Here is a short vid of all the kites I had made up to a few months ago and several NPSs.

shortlineflyer - 24-8-2015 at 11:02 AM

3/4 oz isnt really light weight ripstop in my opinion. I consider the light weight to be 1/2 oz or less, medium to be 3/4 oz to 1 oz and heavy to be anything above 1 oz . check out texlon they sell kite fabric there and its really cheap.

kallie.spidahl - 24-8-2015 at 02:42 PM

WHOA DANG RANDY! Those kites in that video are all awesome! Perhaps I'll start with a NPW and cheap materials so I don't wind up wasting a ton of money and end up having to scrap a kite. I have a few yards of ripstop leftover from a panel replacement I did on my cabrinha LEI that I thought I'd mess around with.

I also like the idea of once I'm ready to make a bigger single skin, doing it with really cheap fabric to make sure the design is ok before making a final copy.

Thanks all! I'm excited!

PHREERIDER - 24-8-2015 at 03:48 PM

get excited!

bigE123 - 25-8-2015 at 12:22 AM

@kallie.spidahl The plans you have shown are the ones I have used to build my "new" single skin kites.
Two words of warning, the plans are expecting you have all the skills, in both building and design, there are no notes and explanations. For mine I have changed the design from the initial "default" as it's primarily a parafoil design, you need to decide on the wing shape, AoA, how many cells etc. The second is, it is a challenging build, the formation of the nose is quite tricky and needs a lot of patience.

I'm not sure on the material weight you're quoting as I buy mine in metric weight, I have used weights 40g/m2 and 48g/m2, the 40 in my opinion too light and needs extra reinforcement, I now use 48g/m2 fo this type of kite.

For thread you need to use non cotton, i.e. a polyester based thread, I use a site in Germany to get thread and bridle line: thread http://www.metropolis-drachen.de/cgi-bin/iboshop.cgi?show370.... Bridle line I use 33DaN for secondaries and 50DaN for primaries. http://www.metropolis-drachen.de/cgi-bin/iboshop.cgi?showd36...
My first build I used knots for the bridle, since then I have gone fully knot-less, every line has a loop made on each end so everything is now connected via a larks head, but once you go this route every line has to be spot-on as there is no room for error.

When you look at the plans I went for triangular ribs, the bridle attachment points are marked on the plans, they are at the top of each triangle.

You need to have a good look at the plans and decide: what size to build, it's design, where you are going to reinforce, how to attach bridles. For the nylon inserts it's garden "strimmer" line ideally 3mm but 2.5mm is more widely available and is just as good.

Hope that helps, it's not a first time builders kite but is something that is awesome once built and tuned. Tuned... yes you then need to fly it and understand if it's not flying quite right what to do to correct it.

Personally I would get an NPW build under your belt, a much easier build and you can really get to grips with building/bridling and tuning, it may be a step towards the single skin you are looking at, an NPW has very little material waste (one or two colours) where as the other needs careful planning and has much more waste, for my first 12m2 I ended up needing over 20m of material.

Randy - 25-8-2015 at 06:03 AM

I downloaded the single skin program, but can't seem to get it to execute. I'm using Windows 7. I see there is a Windows 8 update, but don't think I need that to get it to run. Anybody have any suggestions?

bigE123 - 25-8-2015 at 07:19 AM

I've got Win 7 professional and it works fine, the one I downloaded was singleskin_0.3_Setup, I'm sure I tried a later version but that wouldn't run

kallie.spidahl - 25-8-2015 at 12:38 PM

Quote: Originally posted by bigE123

Personally I would get an NPW build under your belt, a much easier build and you can really get to grips with building/bridling and tuning, it may be a step towards the single skin you are looking at, an NPW has very little material waste (one or two colours) where as the other needs careful planning and has much more waste, for my first 12m2 I ended up needing over 20m of material.

WOW thanks so much for all of the help. That's seriously more information you've given me in one post than months of searching online! Unfortunately instructions seem to be nonexistent in the software/at all, so starting off with a NPW sounds like the winning plan!

kallie.spidahl - 25-8-2015 at 12:40 PM

Quote: Originally posted by Randy

I downloaded the single skin program, but can't seem to get it to execute. I'm using Windows 7. I see there is a Windows 8 update, but don't think I need that to get it to run. Anybody have any suggestions?

Hmm. I also have Windows 7 (partitioned on a mac) but it's running fine. You downloaded "SingleSkin_0.3_Setup.exe" correct? I didn't install the update either...

Randy - 25-8-2015 at 03:25 PM

I did download the file you mentioned. I tried it on my little netbook and it is running so I don't know what the problem might be with my desktop. When I first got it to run I thought I was getting some kind of really strange error message page until I realized it was in Russian. Once I switched to English it made sense.

BTW - the best of the NPW plans are the ones by Tom White, for the NPW5 and NPW9. There is a lot of detail on the plans for the 9 which is very helpful in building any NPW.

kallie.spidahl - 26-8-2015 at 09:33 AM

:thumbup:

jadog - 26-8-2015 at 01:52 PM

Hey Kallie! Welcome to PKF!

FiniteState - 26-8-2015 at 02:17 PM

Hi Kallie,

I joined PKF just to reply to you! Been a lurker for a couple weeks as I've been building my first traction kite, too (thank you everyone on this forum!), and I wanted to share a few things that got me started.

I built a small 1.8m2 Teega-style NPW, the plans of which are referenced here: http://freedom2000.free.fr/NPW_index_eng.html. Why the Teega specifically? I had a lot of trouble finding good walkthroughs for every part end-to-end, and I thought the Teega plans were most helpful in terms of understanding the general construction, knots, and bridling. Now that I know what I know and have flown mine a couple times, I'm planning on building another one that is larger, and I'd probably just do a regular NPW9b instead of the Teega.

I found NPWBill's site helpful for more details on sewing techniques: http://tismaz.com/NPWBill/NPWBill.htm. Specifically the bit about hotcutting two pieces together at the seam to baste the seam -- that is, if you want to avoid pinning pieces together so they don't shift while sewing. From my experience making ultralight sleeping bags, I cut my ripstop with a cordless (butane-powered) soldering iron on a glass table and a steel square for a straightedge. Also, I ended up using a beading foot on my serger to inlay the reinforcement lines into a rolled hem, which allowed me to avoid two passes per seam.

I had a lot of trouble getting the bridling calculator running from the freedom2000 site, as I'm running Win8 and Win10. I ended up running it in a WinXP VM (shudder). In general, it feels like all of the NPW resources are from the 90s, all the way down to the comic sans web site font...

By the way, I had intended for it to be a 2m2 kite, but I lost just a few cm when trimming some pieces to fit better. I learned that I needed to recalculate bridle attachment points and lengths based on my finished seamed/hemmed sail, not the original plans. Don't make this mistake.

Oh, here's my kite...

I'm waiting for my flying lines to arrive, so I just attached it to something temporary for practice -- and to help keep the bridle lines from tangling.

Windstruck - 26-8-2015 at 02:36 PM

Dear Finite - welcome to PKF! That is one fine looking kite you have there. I like the color scheme and it is clear from the photo how much you are enjoying flying it! I haven't ventured into this realm of things (sewing my own) but am always thrilled when others do so. :thumbup:

Randy - 26-8-2015 at 06:18 PM

Hey FiniteState - welcome to PKF! Your kite looks great. Its funny you chose the Teega because of the detailed instructions. I was scared off by the Teega instructions, so had to build a simpler NPW 5 for my first kite. BTW - you don't really need flying lines - you can fly it off the handles and use if with a skateboard or SUP, or just static for fun. (Just be sure to get proper protective gear!). Keep up the good work.

bigE123 - 26-8-2015 at 10:52 PM

Nice one and welcome FiniteState! I use double-sided sticky tape to hold the material together for the first sew, open the two edges and take the tape off, BTW for an NPW I don't do any hot cutting as all the "raw" edges are rolled in to the seams. Once you get that Teega on long lines it'll really come to life, I maybe teaching my Granny to suck eggs here, but... you may need to tune the leech lines in the TE once it's on longer lines, shortening the wing ones stop wing tip flap, the middle section will help the nose, but go to far and the kite will back-stall.

FiniteState - 26-8-2015 at 11:22 PM

Thank you, everyone, for the warm welcomes! I'm excited to put the NPW on long lines, but now, Randy, you've seeded the idea of using it for mobility already.... BigE123, thanks for the tip. My leech lines are safety-pinned in place at the moment at the recommended lengths so they'll be easily adjustable. That said, I'm not completely sure what the ideal tuning looks and feels like, just going by gut at the moment. I know I have a few bridle lines that need adjustment, too. What's the best way that people adjust them? What happens if they're too short after tying? Do most people go with the spliced loop nowadays and leave a little just-in-case tail until it's determined to be good?

Really appreciating the tips! Seems like such a nice community -- I've got a lot of dumb questions for you all to answer.

-DL

FiniteState - 26-8-2015 at 11:52 PM

I finally got Tom White's NPW9b calculator working -- and I have to agree now that it's way easier to understand!

Some clarification questions though... Does the normal NPW9b not require slight gathering of the trailing edge that the Teega has? What are people's thoughts on the vnose bridling vs standard nose bridling?

Thanks!
-DL

bigE123 - 27-8-2015 at 03:24 AM

The Teega came after the NPW 9b and hence the addition of the leech lines and rounded wings that NASA didn't use. I did upgrade my 9b with lines in the TE and did find it helped the nose a bit.
I can't get my NPW9b calc to run since upgrading but from memory I used the V nose bridle.
For my earlier builds I used knots for the bridles, if you have a short line your two options are: to either replace it, or shorten the others by how much that one is short. When I make my bridles I cut and remeasure the first one, then make the others relative to that. i.e. if A1 is 100cm, A2 is 90cm I cut A2 10cm shorter than A1, just my way, I find I get less errors.

PS just thought of another thing for a short bridle, make the bridle attachment for that one a bit longer, obviously depends on how you attach.

Randy - 27-8-2015 at 04:38 AM

I've always used the standard nose on 9b kites. The 9b doesn't use the trailing edge gathering (which is what Ian was saying about not using a leech line.)

Ian did come up with an enhancement for the NPW nose which is very easy and worth trying. You run a nylon support in the seam on the main panel up through the nose down to the 3rd bridle point. He prefers nylon "strimmers" - which are the stiff nylon lines used for power lawn edgers. I never could find a small amount of that material at a reasonable price so I used the heaviest nylon cable ties I could run in the seam. Does add some nice support in the nose area. I added another wrinkle by building small pockets and used them for the attachment points in the nose and put in small cable ties bent in to a D shape to support the nose. Does it all help? Won't know until I get my wind tunnel finished.

Here are a few pictures.

FiniteState - 27-8-2015 at 11:33 PM

Oh, that's a neat idea. I have a bunch of that trimmer line, although it has since molded to the shape of the spool since it's pretty old. I wonder if it can be re-straightened in the oven like you can do with mono fishing line (like for mini kite spars). Cable ties look like a good option, too. Did you replace all your t-lines with it?

Also... back to Kallie's original post. I found this thread because I was researching other single-skin kite designs that might be simpler than the NPW, specifically the bridling. Then I remember reading a post where someone used keels/ribs which reduced the number of bridle lines -- I think that was you, BigE123. Have you made a NPW with ribs? Thoughts on construction cost vs bridling simplicity vs performance? I think I'm going to try this for my next NPW.

bigE123 - 28-8-2015 at 12:20 AM

Did someone say keels?
Like these on my 6m NPW?

I've put keels on a few of my NPWs, more as an experiment, which I fitted to my 12m, 6m and 3m kites. In terms of cost there is not a huge amount of material needed, what you do need is more time, the keels probably took nearly as long as the rest of the kite! Performance wise it's a difficult one as I have not flown keel to non-keel side by side, what a keel gives is a much smoother kite profile and 5 bridles rather than 10 on each side. So I would expect an increase in performance but it's not a "wow that is like a different kite".

Construction wise there is nothing out there (taht I could find) on design, I found a paper which showed keel depth figures, I initially tried parabolic keels, I drew full size the bridle lines (need to do some maths to calculate the angles between each line) that gave me the profile of the kite and on to that I created a plan of my keel.
To construct I hot cut four keels, sandwiched two together with a line running along the full top edge to give me bridle attachment loops. If I did it again I'd go triangular keels and reinforce the tops like I do on my new style builds.
Hope that gives you a taste of what's involved, it's not something you simply find plans for you need to create/design them from scratch.

You mentioned your strimmer line being bent, don't worry it goes straight when slid in to the seam.

Randy - 28-8-2015 at 03:57 PM

FiniteState - a couple of ideas for easier NPWs. I really like the Single Keel NPW. Less bridles than any NPW, and no nose darts, supports, etc at all. Sean and I have used them to pull landboards too. Its very stable but can turn almost like a stunt kite. I can provide links to plans and a bridle spreadsheet, if you are interested.

Another really simple build is the NPWC. Only a few bridles, 3 panels and the very easy to build (though I'd never done a curved seam before.) It is a challenge to get the tuning right, though and unlike most kites its really best using 3 lines. Its really sort of an experimental kite Here's a video. (Ha ha - great chance to plug my latest project.) 2e5.com has the plans and details.