Date: Tue, 6 Apr 1993 16:15:46 GMT From: sasaki@netop3.harvard.edu (Marty Sasaki) Message-ID: <1993Apr6.161546.21944@das.harvard.edu> Organization: Harvard University Subject: Re: High Wind Kites & Brakes The first screen door kite that I saw and had a chance to fly was a North Shore VIP (designed by our own Darrin Skinner). For those who haven't seen or flown a screen kite, part of the sail is replaced with a very wind pourous material, often fiberglass and plastic window and door screening material. The screening material reduces the effective surface area and increases drag. This reduces forward speed, which also reduces pull significantly. Others have experimented and manufactured screen kites to cope with higher wind without changing the basic flying characteristics of the kites. One problem with screening is that the placement and size of the screen can be critical to the kite's performance. I once placed a screen panel on a kite in the perfect place to make turning horrible and with no noticeable decrease in speed or pull. The next change that I saw on the flying field were "diapers". These were rectangular pieces of fabric that were placed between the two standoffs on an NBK. The NBK has two parrallel standoffs. The Duel Drones, a pairs ballet team from Connecticut were experimenting this way. Other things include the triangular patches on kites that had only one standoff, a triangular piece of fabric on the back side of the kite supported by spar which was at right angles to the spine and pointing backwards. Dave Simpson, a Rhode Island flyer and member of the High Flyers Flight Squadron, began experimenting with rectangular pieces of fabric strung in front of the kite between the two flying lines. These worked pretty well, but the size of the fabric could adversely effect a kite's performance, it depends on the wind. Dave has recently started using fiberglass screening instead of the fabric. He calls these gizmos "Wind Tamers" and has started to sell them. Dave says that he first saw them in the UK, or at least that's what I remember him saying, I could have mis-remembered. Anyway, the wind tamers do a good job of slowing down a kite. The screening is pourous enough that turning and general flyability of a kite are changed very little. Different widths have more or less drag. Obviously, the wider widths have more drag. These work great on most kites. On really radical, fast turning kites the slowing effect on the turns might take some getting used to. I put a smaller screen on a Katana and I couldn't do a lot of the stunts that I normally do with the kite. No problems at all with the team kites. I hear that you can get a Magnum Opus with a screen "air brake" on the back ofthe kite and that Chicago Fire is selling these things for other kites as well. In high wind, "air brakes" and screen kites do make a difference. If you face occasional high wind you might look into the add on air brakes, more prevalent high winds suggest screen kites. -- Marty Sasaki Harvard University Sasaki Kite Fabrications sasaki@noc.harvard.edu Network Operations Division 26 Green Street 617-496-4320 10 Ware Street Jamaica Plain, MA 02130 Cambridge, MA 02138-4002 phone/fax: 617-522-8546 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: 6 Apr 93 18:52:54 GMT From: lucifer@emx.cc.utexas.edu (Light-Bearer) Message-ID: <1psji6INNm87@emx.cc.utexas.edu> Organization: The University of Texas at Austin, Austin, Texas Subject: Re: High Wind Kites & Brakes In article <1993Apr6.125507.19482@nic.funet.fi> salanne@convex.csc.FI (Simo Salanne) writes: >In <1ppv3hINN9kt@emx.cc.utexas.edu> lucifer@emx.cc.utexas.edu (Light-Bearer) writes: >(text deleted) > >>Some other folks also had vented kites but with Dragons added... these >>are triangular pieces of ripstop that connect to the stand-off and the >>bottom spreader and effectively block airflow through the sail. I didn't >>get to fly one, but the people I talked to said they weren't sure if they >>liked these or the mesh better. > >Could somebody describe this "dragon technique" in more detail... > >Smooth Winds >Simo Salanne Sorry Simo, that wasn't a very clear explanation. If you view the kite belly-down and nose facing away: - - / | \ / | \ / | \ / | \ / | \ / | \ / | \ / | \ /========|======= -- =======|======= \ The Dragons (note, this may not be how they spell the trademarked name), are placed on the standoff and the cross-spar: - - / | \ / | \ // | \\ // | \\ / / | \ \ / / | \ \ / / | \ \ / / | \ \ /===/=========\== -- ==/====|====\== \ Well, it's hard to draw in ASCII, but I hope you get the idea. Disclaimer: I don't remember the manufacturers name, and I don't know if they have copyrights or patents. I'm just repoting what I've seen at a public event. Hope that clears things up a bit. Dean -- Q \ | Dean C. Hines, Astronomy | dhines@astro.as.utexas.edu | |-+=========|> | University of Texas | dhines@pan.as.utexas.edu | / \ _/ | Austin, TX 78712 | -----------------------------| -----------------| "No, it's not a spaceship, it's a Stunt Kite... sheesh! | = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: 09 Apr 93 20:33:42 PDT From: danr@crash.cts.com (Dan Rubesh) Message-ID: <1993Apr09.203342.15255@crash> Organization: CTS Network Services (crash, ctsnet), El Cajon, CA Subject: Re: High Wind Kites & Brakes Marty writes: [lots of good info deleted] >I hear that you can get a Magnum Opus with a screen "air brake" on the >back of the kite and that Chicago Fire is selling these things for >other kites as well. >-- >Marty Sasaki Harvard University Sasaki Kite Fabrications >sasaki@noc.harvard.edu Network Operations Division 26 Green Street >617-496-4320 10 Ware Street Jamaica Plain, MA 02130 > Cambridge, MA 02138-4002 phone/fax: 617-522-8546 Actually, the brake that Chi Fire is selling is made of a screen reinforced translucent plastic (vinyl?) like is used in the Radian Prism or windsurfer sail windows. It does help to slow the Magnum Opus some in higher winds. Dorothy Wolfe tells me that it's being made by one of the Chicago area kite makers for them.. They call it a 'Bikini Brake'. I haven't tried it on anything but the MO as yet, but it should work well.. Only takes a few to install/remove.. - - - - - - - - - - - - - Dan Rubesh Wind Wizard, Purveyor of UUCP: {ucsd, nosc}!crash!danr GO Stunt Kites & Accessories ARPA: crash!danr@nosc.mil FLY A P.O. Box 5747 INET: danr@crash.cts.com KITE! Ventura, CA 93005 (805) 859-5654