JerryBaumchen 1,240 #26 July 11, 2008 Hi Bill, That is also my memory of what Dan said. IIRC, the first jump on a glued canopy was about '66 when Loy Brydon jumped a Rogallo wing with glued seams. The concept has been around a long time; the details are causing the production delays. JerryBaumchen Quote Share this post Link to post Share on other sites
AggieDave 6 #27 July 11, 2008 Quote>Unless you had some kind of gas reaction that caused gases to inflate >your canopy from the inside. . . Right. Specifically I'm talking about inflating it with an internal source of compressed air, nitrogen or CO2. Think one of those life raft cartridges. This is what Hooknswoop was talking about 6-7 years ago. There hasn't been a whole lot of new stuff hit the market in regards to technological increases since then either. I'm willing to bet we'll see some "pumped up" canopies being played with as speed flying gets more and more popular.--"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites
billvon 2,683 #28 July 11, 2008 >the details are causing the production delays. Indeed! I would point out that Dan has built canopies like this (glued w/structural fabric) but 1) They didn't fly well, because modern parachute patterns _rely_ on a certain amount of deformation to get to their inflated shape 2) They would cost on the order of $30K to manufacture. Quote Share this post Link to post Share on other sites
RB_Hammer 0 #29 July 12, 2008 QuoteSpecifically I'm talking about inflating it with an internal source of compressed air, nitrogen or CO2. Think one of those life raft cartridges. A lighter than air gas mixed in would be nice..."I'm not lost. I don't know where I'm going, but there's no sense in being late." Mathew Quigley Quote Share this post Link to post Share on other sites
d123 1 #30 July 12, 2008 I think that it would be really interesting to have a wing that allows you to change in flight the Aspect Ratio (while keeping the same area) and area (while keeping the same AR). This will give you real time control over the glide ratio and speed.... my 2 cents ... Maybe it will be more suitable for paragliding or kiting than skydiving ... dunnoLock, Dock and Two Smoking Barrelrolls! Quote Share this post Link to post Share on other sites
cobaltdan 0 #31 July 12, 2008 Quote>the details are causing the production delays. Indeed! I would point out that Dan has built canopies like this (glued w/structural fabric) but 1) They didn't fly well, because modern parachute patterns _rely_ on a certain amount of deformation to get to their inflated shape 2) They would cost on the order of $30K to manufacture. Actually they fly much better than nylon wings for exactly the reason you mention. We can accurately predict in software which we developed the exact deformation of a parafoil wing in flight. The challenge is getting our desired shape to match the in flight deformed shape. Ripstop nylon is the limiting factor. By engineering the fabric to resist elongation in a specific pattern we can force an overall desired shape. The first composite fabric canopy we ever produced was a cobalt 95. It weighed 70% less than a ripstop canopy and was so strong that no tapes were required anyplace in the canopy. The measured glide ratio was 65% higher than the exact same canopy constructed in nylon. This canopy was displayed opposite the 1902 Wright flyer in the Smithsonian museum and is now on a museum tour with the Extreme Textiles exhibition. We have since under contract to DARPA produced a series of canopies with glide ratios of >8.4:1 ! Cost is definitely a factor. Our automated production machinery is faster and less labor intensive than weaving however our starting point is a Ultra High molecular Weight Polyethylene fiber, know to jumpers as Spectra or Dyneema. This material is ~ 200 times more expensive than Nylon. So the resulting fabric is much more expensive. What makes our fabric and construction process stronger and lighter for parachutes translates to ballistic protection. We are producing body armor 1/2 the weight currently being fielded. As such the fabric is in extremely high demand, and parachutes applications are being pushed aside. We are in the process of adding machinery for higher production, but currently our production is booked for ~ 16 months on government orders. (I am sneaking in a small run of fabric for Jyro to build his personal swoop machine)... We have papers available on some of this work, contact me and i can send you a copy. Regards, Daniel <><>Daniel Preston <><> atairaerodynamics.com (sport) atairaerospace.com (military) Quote Share this post Link to post Share on other sites
