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bjornufknu

Building a "kite" from zp and HMA

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I'm in the middle of this fix-idea I have... That is building a kite from zp fabric and HMA lines.
I'm planning to build a steerable kite. Not the size of a big "kite surfi'n"-kite, but a smaller one, and with no inflatable ribs.

I have searched the web for guidance on how to build a kite (measurements, material etc), but I have had no luck in my journey to settle my mind, so I am now asking for help in the skydiving community.

Anyone out there with "blueprints" on a kite? Anyone out there that knows where one can get hold of HMA lines?
Any help/thoughts/experience or cheers would be awsome.
Thanks!
d.d.s.

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It isn't that hard. Just build it. Take some measurements off of a canopy and scale it down. You aren't trying to break any world records, just make something that flies. The fabric isn't tat big of a deal either, especially if you consider it a first effort. Buy some cheap fabric and build it. You will learn so much in that process and you might decide to build another. You can upscale the budget and effort level then.

-- Jeff
My Skydiving History

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you can use ZP but youd be better off with poarcher marine skytex sailcloth, or the like
also id use 100# spectra for the bridle lines and HMA for the flying lines


heres a plan for the "nasawing" its a traction kite without inflatable cells
http://www.xs4all.nl/~pdj/nasaplan.htm

pretty much any online traction kite store will have what you need.

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Build it to almost exactly the same design as a higher aspect ratio than usual HP main.

I recently bought a Crossfire power kite. It has 9 cells, cross-port-venting, a partially formed nose, crossbracing, A,B,C,D lines, seperate break lines, the lot. It's even made of ZP and came with spectra lines.

It is in effect identical to a parachute... so just scale down your favorite canopy and build it in miniture.

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It is in effect identical to a parachute... so just scale down your favorite canopy and build it in miniture.



Hey, could you measure the length of the A vs. D. lines and the chord between them? I'd like to know the trim angle of a kite vs. a sport canopy. I'm thinking the line trim is very important and pretty hard to figure by "trial and error".

Thanks.

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I'll take a look next time I have it out. There are some kites which provide the ability to adjust the trim.

Remember things aren't so critical as with a parachute so finger trapping and sewing isn't necessary. It's common for the bridle lines to be larks headed over a knot on the suspension line. Thus if you have a series of knots in the suspension line you can adjust the angle of attack of the whole wing simply by moving the larks head attachments on all the lines up or down one knot on the suspension line.

(mine doesn't have this feature though so I should be able to give you factory setting figures).

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Ok, at the risk of shamelessly violating the manufacturers intellectual property rights, the difference between the A and D lines on my kite is roughly: 0. That's right, nothing!

The first set of lines (from center) are roughly as follows (in inches from canopy to cascade for the each pair – ie there are two A lines, two B lines etc etc):
A: 36
B: 35
C: 35
D: 36
Each attachment point is 7" from the next meaning there is 21" between the A and D lines.

There are 3 further sets of lines, each with the same relative lengths although they become progressively shorter towards the outer edge of the canopy to produce a slightly crescent shape to the wing edge-on. The last set of lines goes straight to the edge of the wing.

Each A/B/C/D line splits 18" from the kite into two before attaching to the bottom skin in the normal way. (ie there are two 36" A lines, two 35" B lines and so on as I have given the measurement for the lines from canopy to the second cascade where the A lines meet the B,C and D lines).

The brake lines are separate and adjustable so there's no point me telling you their length. Needless to say, just as with a canopy they need to be bowed out slightly in normal flight but you should be able to easily stall out the side of the canopy if you wish.

The lines are attached to handles which are bent away from you to allow for easy control of the brake lines. You're probably best off taking a look at a kite here, or even better would be getting a kiting lesson so you know how the thing should handle... hell there's even a "right" way to hold the handles to allow for effective control over the wing. An alternative control mechanism would be to attach each suspension line to the end of a bar and create a pulley system for the brake lines. Id guess this may even be best if youre building something very big.

All the suspension lines come together in staged cascades within the first meter or two of the kite. After that there is simply 1 line for each side of the wing with all ABC and D lines going into just one line for each side. When you turn the kite you are effectively doing what would be a harness turn on a parachute - there is no such thing as front or rear riser turns with a kite (unless you wanted to build it so you could of course... it's your project after all).

I hear though that harness turns are the most efficient turn you can make (so I hear anyway) so it makes a lot of sense to me to have a kite set up this way, especially given the fact your essentially flying a parachute with a wing loading of about 20:1.

Brake lines are of course separate (giving you 4 lines in total) but are not the primary method of controlling the kite. They are however useful for re-trimming it, reversing it or stalling out a side to produce a fast spin and can be used to control the amount of power your kite produces.

*now the obligatory warning*

Be fucking careful. I damn nearly killed myself this evening in winds which would be legal to skydive in. I was flying a 10.5 square foot kite (although they're generally measured in meters). It can easily lift me off the ground if I want it to and I generally spend my time being dragged about the field at speed. This kite is one of the smallest in its class as I bought it to fly at the DZ on days I was winded out. Im now thinking that may just be a tad too fecking dangerous anyway. Kites are commercially available anything up to sizes above that which Luigi would be comfortable jumping!

Build yourself some "kite killers". Seriously, this isn't even a joke, you MUST do this. These are a pair of leashes just like on a surf board. You put one round each wrist and the end of the leashes go to the brake lines of the kite. If you're ever in trouble (which I damn near guarantee you will find yourself the first time you try to fly this thing) simply let go. The leashes will ensure the brake lines are pulled right in and the kite simply collapses, flying gently to the ground.

Without this bit of kit you will either lose your kite or hurt yourself. Seriously!

Now, have fun and post pictures. B|

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Be fucking careful. I damn nearly killed myself this evening in winds which would be legal to skydive in. I was flying a 10.5 square foot kite (although they're generally measured in meters). It can easily lift me off the ground if I want it to and I generally spend my time being dragged about the field at speed. This kite is one of the smallest in its class as I bought it to fly at the DZ on days I was winded out. Im now thinking that may just be a tad too fecking dangerous anyway. Kites are commercially available anything up to sizes above that which Luigi would be comfortable jumping!



he he - i did warn you!!!! :D

Stay away from the edge of the gorge......
Never try to eat more than you can lift

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