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BlackOpSource
Newbie
Joined: 10 Aug 2007
Posts: 32
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 Posted: 14 Oct 2007 07:36:57 pm Post subject: |
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Say, hypothetically, that I want to build a trick kite. A delta-shaped trick kite. A really big delta-shaped trick kite. (If you don't know what I'm talking about, think "hang glider wing".)
Now, it seems to me that the most efficient wing would
have a cross-section (perpendicular to the kite's direction) such that on either side of the keel (central longitudinal spar), it would be a catenary curve.
Additionally, say I really want to build this kite; that is to say this is not a thought exercise. I have limited resources, so for the purposes of cost-effectiveness, structural integrity, and aerodynamics, I want this kite's wing to be one big piece of plastic. So, I need to unroll the surface to make a template to trace onto the plastic to cut out.
So, I need to be able to find the distance between two points along the catenary curve and translate this into variations in the distance from the nose of the kite to the trailing edge of the wing.
I will note that since this is a large surface, I don't like the idea of using calculus as anything other than a tool to develop a definite formula, because of its inexact nature (You know, limits and all.).
Useful topics to look up on Wikipedia-
-Stunt kite
-Gaussian curvature
-Developable surface (a.k.a. "unrollable surface")
-Catenary
-Distance
Help me.
~BlackOpSource |
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DarkerLine
ceci n'est pas une |
Super Elite (Last Title)
Joined: 04 Nov 2003
Posts: 8328
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| Posted: 14 Oct 2007 07:38:12 pm Post subject: |
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| Calculus is not inexact. Neither are limits. Limits are the most exact thing you could imagine. |
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lordofthegeeks
Advanced Member
Joined: 13 Jul 2007
Posts: 280
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| Posted: 14 Oct 2007 09:27:09 pm Post subject: |
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Get someone to film you when U first Use it.
Then we can all see your demise. J/k
Also Try this Quick Goole search
Big Kite Plans
Hope it Helps 
btw I lost a Airplane kite flying it in high winds on the top of a hill. It flew pretty well 
Last edited by Guest on 14 Oct 2007 09:27:44 pm; edited 1 time in total |
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BlackOpSource
Newbie
Joined: 10 Aug 2007
Posts: 32
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| Posted: 15 Oct 2007 08:30:30 am Post subject: |
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lordofthegeeks wrote: Get someone to film you when U first Use it.
Then we can all see your demise. J/k
Also Try this Quick Goole search
Big Kite Plans
Hope it Helps [post="114455"]<{POST_SNAPBACK}>[/post]
Also: Sweet Lord, I would die trying to fly that thing! I took kiteboarding lessons in mid-September, and although I didn't get to go out on the water (unsafe conditions for a beginner), I practiced flying a four-line seven-meter (7m²) leading-edge-inflatable kite. I knew how to fly reasonably well, but it still caught me off guard during a gust, and threw me about twenty feet across the beach. Ouch. And foils are supposed to be double or triple the power of an L.E.I. for a given size!
So there'd be a funny video on YouTube of some poor kid launching this huge kite and instantly getting his arms ripped clean off at the shoulders. (This is only funny when it's happening to someone else.)
DarkerLine wrote: Calculus is not inexact. Neither are limits. Limits are the most exact thing you could imagine.[post="114449"]<{POST_SNAPBACK}>[/post] Explain. Because I'm taking calculus now, and this whole "find the value as x gets closer and closer to y" thing seems fishy to me.
Also, I primarily meant in terms of calculator programming, so I could put in some parameters and press "Go" and let the calc deal with it while I'm sleeping/reading/at work.
For anyone else, I'm looking for something about this shape, and of about these proportions, but maybe about half of that size.
~BlackOpSource |
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Weregoose
Authentic INTJ
Super Elite (Last Title)
Joined: 25 Nov 2004
Posts: 3976
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| Posted: 15 Oct 2007 12:35:24 pm Post subject: |
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BlackOpSource wrote: DarkerLine wrote: Calculus is not inexact. Neither are limits. Limits are the most exact thing you could imagine.[post="114449"]<{POST_SNAPBACK}>[/post] Explain. Because I'm taking calculus now, and this whole "find the value as x gets closer and closer to y" thing seems fishy to me.
Last edited by Guest on 15 Oct 2007 12:51:44 pm; edited 1 time in total |
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BlackOpSource
Newbie
Joined: 10 Aug 2007
Posts: 32
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| Posted: 15 Oct 2007 03:58:10 pm Post subject: |
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Ah. I see.
Okay, having said that, I guess my real issue is this: Can my catenary "cone" even be unrolled? If not, how about a parabola? Or do I just have to approximate it by building it in sections? |
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