Kitebuilder.com

[Barbara Meyer]

I am curious how other people frame their deltas. I am especially interested in deltas that are 48" tall and larger.
In the past I have always used filament wound epoxy, but have been thinking about switching to Carbon. Has anyone else used Carbon? How do you calculate what size is needed? Do you notice a difference in performance?
Thanks for any info
Barbara Meyer

[KiteSquid]

Barbara,

The first thing I notice is that Carbon is a little harder on my wallet...

I usually just use SkyShark P300's in just about all the kites I build, no matter what kite it is. If you remember my Iris Edo it is framed entirely with them.

They are a combination tube as they have both longitudinal and radial fibers.

You can cut them anywhere on the length of the tube, like pultruded. Normal wrapped tubes have to be cut at the reinforcement.

I can usually make a stiffer, or lighter kite than with any other sparing material.

I could not find SkyShark P series tubes in Steve’s catalog…

If you want to use pultruded tubes, it depends on what your goal is. Do you want a stiffer frame or a lighter frame, or something in between.

Start here:

http://www.kitebuilder.com/inventory/spargrap.htm

Steve has put together a chart of the most common spars on the market.
_________________
VR/
KiteSquid
AKA TakoIka
AKA Harold
King George VA


P.S. Yet another post by the Squid..... Doesent he ever shut up???

P.P.S. The wind is like the air, only pushier.

[Barbara]

A little history, when I started building deltas, wood was the cheapest, most available spar material and worked quite well. In fact, I still use wood dowels to spar my light wind delta sled kites. Thebiggest disadvantage is that it tends to warp after being flown in higher winds.
As the kites got bigger, mainly wider as delta conynes and double deta conynes I went to fiberglass epoxy as spars. Usually i use a G50 for vertical spars.
my question was prompted by a couple of thoughts. First a Carbon, like a 2200 is smaller physically and thus needs smaller pockets, tunnels, etc, and there are several standard fittings that work well with it. Also the thought that since as Kevin Shannon mentioned to me, Carbon wants to stay straight giving you a stiffer kite that should perform better as to lift. Then not having enough of the G50's to frame my kite, they are unfortunately on back order so I have to use something else.
So I made up a set of 2100 spars to fit an existing kite, finally today we had wind so off to the local park for an unscientific test. The kite I used is 49" tall and is a double DC with a long banner tail. Up it went with the G50's, flew great, you could see the entire frame flexxing in the wind, very stable, nice angle of attack.
Next I switched to a set of 2100's in the vertical, leaving the spreader as a J65. It went up great, it did not flex as much, a degree or two better angle of attack. the problem came in the gusts and wind shifts. Here in Minnesota, the winds are normally not nice and smooth like on the coast. We have lots of turbulence. There was quite a bit more oscilation and not as quick of a recovery to a stable position with the Carbon.
So, as a result of my test, I'll stay with the fiberglass epoxy, next test will be a size smaller spar to see how that does. The E40"s should work just fine.
Barbara

[stevef]

A lesson learned. Ive always said, very often the Epoxy Tube is the best, all round single line kite spar. Yes diameter to diameter, not as stiff as Carbon, but as you discovered from your test.... stiffer is not always better.

I get telephone calls all the time asking: "What is stronger, Graphite or epoxy?"

What do you think...
_________________
Steve Ferrel
Go Build a Kite!
Measure once, buy twice!

[kitenerd]

Hi Barbara,

Up until a few years ago, Into the Wind used to put a spar chart in thier annual catalog. Similar to the one Steve has on his site, the cool thing about this chart was that it was all based around 1/4 dowel (as a stiffness of 1) which was easy terms to think in. I still keep this chart in my work area so i can decide what to use. If you want, i could fax you a copy, it is very handy.

be happy

A
_________________
----------------------------------->
Without wind - i lack direction!

[Barbara]

Thanks for the tip Arnold. I dug thru my catalog file. Their 1985 catalog did not have it, but by 1987 there it was along with typical uses of each, and later years were even more complete. Now to copy and put somewhere I can find the next time I need it.
Oh, by the way, I finished the parachute last week, now if the kids will give me the critter back. Next the glueing of the climber/release, I may have to bring it to Oregon for you to finish!
Thanks
Barbara

[kitenerd]

i know how that goes - i keep looking at the spinsock kit i got fro Mike Gee going "do i really want to tackle that?!?" - not enough time

see you in 2 weeks

A
_________________
----------------------------------->
Without wind - i lack direction!

[Progcraft]

[KiteSquid]

There are several kite spar charts on the web but most do not refrence wood:

Here is some in depth text on selecting spars. Please read before going farther:

http://www.kfs.org/~gaffer/Specs/cokecan.html




http://users.techline.com/lord/techdata.html

http://www.nic.fi/~sos/spars/spars.htm

http://www.flash.net/~swikel/sharkfiles/Spar_Data.htm

and how could I forget this one:

http://www.kitebuilder.com/inventory/spargrap.htm
_________________
VR/
KiteSquid
AKA TakoIka
AKA Harold
King George VA


P.S. Yet another post by the Squid..... Doesent he ever shut up???

P.P.S. The wind is like the air, only pushier.

[KiteSquid]

Barbara,

You might try to shorten or soften your spreadder a little to put back some dihedral that you took out by stiffening your leadining edges....


Just a thought.
_________________
VR/
KiteSquid
AKA TakoIka
AKA Harold
King George VA


P.S. Yet another post by the Squid..... Doesent he ever shut up???

P.P.S. The wind is like the air, only pushier.