Date: Mon, 26 Jul 1993 06:32:28 -1000 From: thompsontra@phibred.com Message-Id: <9307261632.AA21534@phibred.phibred.com> Organization: Division of Applied Sciences, Harvard University Subject: Bridle / Spine adjustments on the Shuttle. Hi guys (and gals) -- Well this weekend in Iowa and Missouri provided about the first break we have had from the rain and offered me the perfect opportunity to try out my newly built stack of Shuttles. For those of you not familiar with the Shuttle is is basically a two-line diamond with an exagerated width. (The pattern comes from the book "Stunt Kites to Make and Fly"). The author recommends this as one of the first kites that you build because of the relative ease of only having to deal with two panels and two fiberglass spars. So in the last few rainy (OK, flood prone) weekends I've set out to build a stack of this design. Now the fun part, when I get the kites to the field it seems that whenever they hit a dead spot in the wind (launching, top of the window, sides, etc.) the kite has a tendancy to go into a spin centered around either the right or left bridle point. The spin is so severe (100 or so wraps when falling from the top of the window) that the kite can only be recovered by giving both lines a massive jerk and hoping that it will recover. The only thing I could figure at the time was some sort of mis-adjustment to the bridles, but the fact that it will spin in both directions and is flyable as long as you keep it in constant wind makes me wonder about that one. Besides, I've tried everything I can think of with the bridles to correct this. Last night it occured to me that maybe the problem was with the sail being streched too tight. Before I go chopping up my spars to test this theory, I figured I would ask around here to see if anyone else has had this problem or has any other suggestions. Thanks in advance for the help, everyone here on rec.kites seems to be an unending source of knowledge. Good winds, tight lines and no rain...please!!! ====================================================================== Travis Thompson | Internet: Thompsontra@phibred.com Network Manager | America Online: TTrav2 Microbial Environmental Services | Des Moines, IA | These opinions are my own, etc. ====================================================================== Program: n. A magical spell cast on a computer that allows it to turn your input data into error codes. v. An activity similar to banging your head against a wall with much less opportunity for reward. -- Anonymous ====================================================================== = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Mon, 26 Jul 1993 12:33:29 -1000 From: wjon@okcforum.osrhe.edu (Jon Wagner) Message-Id: Organization: Okcforum Unix Users Group Subject: Re: Bridle / Spine adjustments on the Shuttle. I can't find my reference books at this exact moment, but I seem to recall in dealing with single and dual line kites, that the problem that you are having is due to the bridle points being to close to the nose of the kite. All bridle changes should be made in very small steps (1/4 inch to 1/8 inch moves). If I am wrong then moving the bridles down will make the situation worse, in which case just reverse direction on your adjustments. I have found ( and I am not that good a flyer) that most problems can be worked out by adjusting the bridling points! good luck and good winds jon wagner = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Mon, 26 Jul 1993 12:05:17 -1000 From: salanne@convex.csc.FI (Simo Salanne) Message-Id: <1993Jul26.220517.24231@nic.funet.fi> Organization: Finnish Academic and Research Network Project - FUNET Subject: Re: Bridle / Spine adjustments on the Shuttle. In <9307261632.AA21534@phibred.phibred.com> thompsontra@phibred.com writes: (stuff deleted) >built stack of Shuttles. For those of you not familiar with the Shuttle is is >basically a two-line diamond with an exagerated width. (The pattern comes from >the book "Stunt Kites to Make and Fly"). > (stuff deleted) >Now the fun part, when I get the kites to the field it seems that whenever they >hit a dead spot in the wind (launching, top of the window, sides, etc.) the >kite has a tendancy to go into a spin centered around either the right or left >bridle point. The spin is so severe (100 or so wraps when falling from the top >of the window) that the kite can only be recovered by giving both lines a >massive jerk and hoping that it will recover. Shuttle is an "indian fighter" flown on two lines. (Hope you have the indian fighter articles available, a few weeks back.) I'll guess that when you fly it in the dead spot in the wind, Shuttle flattens out, comes unstable (like real indian fighter) and starts spinning. The "massive jerk" bends the spar, creates the dihedral and stabilises the kite. >The only thing I could figure at the time was some sort of mis-adjustment to >the bridles, but the fact that it will spin in both directions and is flyable >as long as you keep it in constant wind makes me wonder about that one. >Besides, I've tried everything I can think of with the bridles to correct this. >Last night it occured to me that maybe the problem was with the sail being >streched too tight. Before I go chopping up my spars to test this theory, I >figured I would ask around here to see if anyone else has had this problem or >has any other suggestions. You don't have to chop your spars, just add a line behind the kite >From left tip to the right tip, so it pulls them 5-10 cm together. The trick will keep the dihedral. Hope this helps. >Thanks in advance for the help, everyone here on rec.kites seems to be an >unending source of knowledge. >Good winds, tight lines and no rain...please!!! Sorry, but my knowledge does not extend to rains:-) Smooth Winds Simo.Salanne@csc.fi = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Tue, 27 Jul 1993 12:11:21 -1000 From: allanc@syacus.acus.oz.au (Allan Charlton) Message-Id: Organization: Australian Centre for Unisys Software, ACUS Subject: Re: Bridle / Spine adjustments on the Shuttle. One little thing. I think you said you need to give it a "massive jerk". If you're using a nylon line, you will lose a lot of response in the line stretch, and you will need a massive jerk to make it respond at all. If you change to a line that won't stretch you will find that the kite will respond much better. Indians use cotton a little heavier than button thread. On a smallish fighter (about a square foot) I found ordinary sewing cotton worked just fine. It's light, cheap, and doesn't stretch enough to notice. But like all thin lines, it will cut your hands. Allan Charlton allanc@syacus.acus.oz.au