what strength line do I need for the bridles. I was going to use braided fishing line

I was thinking of using 50# spider wire or power pro fishing line for the secondaries and 300 lb dacron for the primaries

I didn't dig through it all, but I think it's in this thread somewhere

http://www.powerkiteforum.com/viewthread.php?tid=29242&p...

What size are you making? I have a very reasonably priced 4 meter for sale.

12+ gets you rolling on grass

Ive been wanting to make one for a while. I think I will make a 2.5 or 3m first then make a low wind one. maybe an 8m

Tom White's NPW9 calculator shows recommended bridle strengths. (Look in the cascade bridle section.) For smaller sized he recommends that the primaries be 2x the secondaries. As size goes up, the two get closer. You would have to go to like 15-20 m^2 to get to 300 lb primaries based on his calculator. 300 lb would be good for flying lines though, for anything less than 7m.

He says 100 lb for primaries, 66 for secondary for kite over 3m and 200 lb flying lines. Just a guide though.

See kiteplans.org for links.

Btw. How does the calculator work on your computers? I have tried it on Win7 64bit but it says that I'm missing a dll and I'm not able to make it work...

Bridle lines keep coming around, my choice is 60kg for primaries and 30Kg for secondaries, whilst fishing line MAY work it's properties are very different to Bridle line, the figure quoted for fishing line is the breaking strain after it has stretched. Whilst bridle line the figure is before it stretches then the brake will be more than the quoted figure. Personally I always use kite bridle line to ensure the kite profile is static (or as close to) without any stretching of the lines going on. Obviously the bridal line used is the same for all sizes of kite, not sure why the calculator increases the line rating, My 11.5m2 NPW has 80/60 line and my new "Hammer" 12m2 uses 60/30 which has over 100 lines, don't forget the load is split across the lines, no one line is taking all the load. I've never has any issues with stretch, I have had a couple of lines break when pulling the kite out of a tree, I'd rather a couple of lines go then than the kite itself ripping at the attachment points.
As I see it if I have 30kg secondaries which means I have 32 lines x 30kg = 960kg load capacity (all things being equal), reduce that by half for any knots and we're down to 480kg, now tell me that's not enough even for me @90kg plus buggy :D

Quote: Originally posted by UnknownAX

Btw. How does the calculator work on your computers? I have tried it on Win7 64bit but it says that I'm missing a dll and I'm not able to make it work...

I run it on a Win 7 Intel e5300 which is 64 bit. Maybe if you google the dll you can download it or try reinstalling it. I've never had any issues with it.

I ran it on a little netbook and it runs fine with an Intel Atom processors. It doesn't need a massive amount of computer power. If you have an old laptop, or any old computer around give it a try.

Quote: Originally posted by shortlineflyer

I was thinking of using 50# spider wire or power pro fishing line for the secondaries and 300 lb dacron for the primaries

Hi shortlineflyer,

I used 80lb Power Pro braided Spectra fishing line for my first NPW kite which is 1.8m. Primarily this was because I didn't want to spend too much money on my first kite -- in general, I like to build prototypes quickly, measure and learn from them, do better next time. I got a 150 yr spool for $18. (The other reason was that I was waiting for braided dacron in the mail and I got impatient -- refer to the "quickly" part of building prototypes.)

Personally I think it was nice for quickly and cheaply enabling me to build my first NPW, and I've learned a bunch now.

However, two things... I had read somewhere on this forum that fishing line has a different or square shape -- the purpose being that it lays better on the spool, but because of this it may be more likely to cause damage when rubbing against other things. Second, it's super thin -- there's no way I would try to do spliced loops with it instead of knots, unless I had a magnifying glass. I used knots to tie it, and ultimately I don't like the look of all the knot ends sticking out. OK, last little thing -- I got it in dark green, and it was a pain in the ass trying to mark on it (center points, etc).

Quote: Originally posted by UnknownAX

Btw. How does the calculator work on your computers? I have tried it on Win7 64bit but it says that I'm missing a dll and I'm not able to make it work...

I'm running Win8.1 and Win10. The error I got was that I was missing MSSTDFMT.DLL which is part of the VB6 runtime. You need to download it, then register it with Windows so that apps can use it. One reputable place to get it is through the Exchange 2000 tool called PST2GB from MS, which happens to include it (https://www.microsoft.com/en-us/download/details.aspx?id=129...). After unzipping it, copy it into your c:\windows\system32 folder, then run "regsvr32 /i msstdfmt.dll" in a Command Prompt window.

run command prompt as admin

http://paracordgalaxy.com/index.php?main_page=index&cPat...

Nanocord .75mm

This is the real deal for bridle line: http://www.metropolis-drachen.de/cgi-bin/iboshop.cgi?show360...

Is Dyneema the same thing as Spectra?

I think it depends which side of the pond you are, it's a trade name, I've read stuff posted regarding to both, there are bound to be differences due to copyrights etc by both manufacturers but, and I'm sticking my neck out here ultimately I think they are very similar. The dyneema I use has an inner core of multi-strand non stretchy stuff with a braided outer sheath.

I believe they are both types of high density polyurethane

Quote: Originally posted by shortlineflyer

I believe they are both types of high density polyurethane

just a different type of proprietary braid I think.

https://en.wikipedia.org/wiki/Ultra-high-molecular-weight_po...

I think it's actually polyethylene

Very interesting read about various uses on the stuff at the link

yeah, i always confuse the two

Thanks! I was able to install MSSTDFMT.DLL and now everything is working as it should.
(Win7 64bit, Intel i7 920)