Date: Tue, 27 Apr 1993 22:00:25 GMT From: irvine@uxh.cso.uiuc.edu (Brent Irvine) Message-Id: Organization: University of Illinois at Urbana-Champaign Subject: Replace Wood with Fiberglass I have a simple Delta kite (83" x 48") that uses wood dowel rods for its supports. They ALWAYS get bent after a day of gusty flying (here in Central IL). I was thining of replacing them with fiberglass rods and was wondering how this would affect its flight capability? Is this a wise move? Should I just buy a whole lot of dowel rods instead at the hardware store? Any suggestions about what to do? -- <><><><><><><><><><> Personal opinions? Why, <><><><><><><><><><><><><><><> <> BRENT IRVINE <> yes. What did you think <> irvine@uxh.cso.uiuc.edu <> <><><><><><><><><><> they were?....... <><><><><><><><><><><><><><><> = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Date: Wed, 28 Apr 1993 20:16:21 GMT From: sasaki@das.harvard.edu (Marty Sasaki) Message-Id: <1993Apr28.201621.1359@das.harvard.edu> Organization: Harvard University Subject: Re: Replace Wood with Fiberglass In article , irvine@uxh.cso.uiuc.edu (Brent Irvine) writes: >I have a simple Delta kite (83" x 48") that uses wood >dowel rods for its supports. They ALWAYS get bent after >a day of gusty flying (here in Central IL). I was >thining of replacing them with fiberglass rods and was >wondering how this would affect its flight capability? > >Is this a wise move? Should I just buy a whole lot >of dowel rods instead at the hardware store? Fiberglass rods will probably increase the performance of your kite, it depends on how heavy the dowels are and how heavy the rods that you replace them with are. If you want to get the most out of the kite, then you can use graphite rods, but these are expensive and probably aren't worth it for your delta. Give the High Fly Kite Co. a call and ask them for advice. Fran or John can tell you everything you need to know. Tell them that I sent you... -- 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: 28 Apr 1993 16:56:25 +0100 From: pat@cs.strath.ac.uk (Patrick Prosser) Message-Id: <1rm9f9$62l@kelvin-02.cs.strath.ac.uk> Organization: Comp. Sci. Dept., Strathclyde Univ., Glasgow, Scotland. Subject: Re: Replace Wood with Fiberglass I've got quite a few deltas (3 by Dan Leigh, and 3 by Patrick Prosser). The leading edge (le) generally gets bent with time, especially so if you fly in damp conditions (unavoidable in Scotland). This also happens to the cross spar (xspar). I tend to have no problem with this, as the deltas continue to perform acceptably with the bent spars. However, I tend to carry a spare set of spars for each of the deltas I have built (and I supply spare spars with all the deltas I have built for others (about 7 or 8 to date)). The spare set are of a different weight for different conditions. I now believe that these different weight spars are a waste of time. In a light wind you want light and stiff spars, whereas in strong winds flexible spars can be an advantage (spill out excess air). What I now do is have a range of deltas, rather than a range of spars. I have re-spared one of Dan Leigh's kites with carbon fibre, replacing the glass and the wood. The kite is now lighter and stiffer. I hate to say this, but it now flies too well! It is so good, I need to add a tail to stop it over-flying. So ... if you want to re-spar I would suggest the following range of options: Xspar: carbon fibre tube, or wood (Ramin) LE: first choice, carbon fibre tube second choice, spiral wound glass (usually black or yellow), third, Ramin dowel last option, glass fibre rod Spine: same as Xspar Wood is good because it is cheap, light, reasonably strong, but is not generally homogenous. Hollow glass fibre tube (spiral wound) is good because it is strong, robust, fairly rigid, light, consistent quality, fairly inexpensive, CF is best and most expensive. On my large deltas (12' to 14' tip2tip) I use Ramin dowel for spine, le, and xspar. I think these kites are amongst the best that I have built so far (wind range, stability, any measure you care to mention). I know I'm not supposed to love an object, but ... let's say I'm fond of those deltas :-) Patrick wood-is-good Prosser = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =