




How's it going? - Part 1: Aerodynamics
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Hang glider:DEV https://www.patreon.com/c/hgdev/home
It's a new year, there's a flurry of new members signing up and it's been about 18 months since I launched this effort, so I think it's a good time to do a summary of what we've achieved so far. Firstly, a really big thank you to everyone, whether you're one of those that signed up in the last couple of weeks or you've been with me from the start, it's making a real difference. I was working on this development stuff before launching this site, along with several other volunteers; Jon Howes, Sean Carslaw Tricot, Julian Todd, Richard Christian, Jeremy Soper, as well as Avian regulars Marek Pisarek and Sebastian Olifiruk. Between us there's decades of experience in aerodynamics, structures, coding and hang glider construction. To be clear, this site isn't like the majority of Patreon sites where the idea is that you pay for the content (videos, blog posts, music, etc) to be created. Here you are paying for the development to be done; the videos and posts are just me trying to keep you updated with what we're doing. Before setting this site up I almost felt guilty for spending time on development when there were things I should be doing that were much more likely to pay me in the nearer term. Knowing that there are people paying me to do the development now means that I feel guilty if I don't spend enough time on it. The development does cost real money, the amount from this site doesn't cover it (even with me and the volunteers time being free, there's a lot of cost in getting stuff made), but it does really show that people care about the future of hang gliding and it tells me I'm not just doing this for myself. For context, I've just spent more than a year's worth of income from this site on a desktop CNC machine (Nestworks, on Kickstarter). For the Wildcat I spent a stupid amount of time manually machining parts, many hundreds pounds more on getting other parts contract CNC'd. For the Puma Dynamique I spent many hundreds on getting parts laser cut. This really slows down the development because you have to be pretty sure of the design before you get it made, then wait for it to come back (or worse, spend days on the lathe or milling machine yourself!). Then when you assemble it, you realise that you've made a mistake or it could be done better then have to repeat the loop. Contrast that with parts that can be 3D printed (or moulded from carbon in a 3D printed mould), where I can quickly knock up a rough design, send it to the printer in the evening, have the part the next morning, tweak the design and have the next version the next day. I'm hoping I'll be able to have a similar process for metal parts with the Nestworks, I'll let you know.
So, lets get into the development! I launched this project 18 months ago (although as I say, we'd already been doing things before that) with this video, which is still a fair summary. Basically the concept is to produce a significant step change in glider design, similar for example, to the change to floating, enclosed cross tubes that defined the 5th generation glider. Simply put, it's to build the first 7th generation glider, hence why we sometimes call this "Project 7". Why do I think this is possible? Well, we're overdue something new. Hang gliders have clearly improved in the last couple of decades, but these have been incremental, stepwise refinements. There hasn't been a really big shift since we went topless (ahem!), more than a quarter of a century ago. Before that the longest gap in generations was 15 years between the 5th and 6th generation, UP Comet to La Mouette Topless. Technology has moved since 1995, especially with regards to composite materials and computer simulation. We should be able to do better and if you do the calcs it turns out we can do better. If you analyse a current hang glider then it turns out we're leaving a lot of performance on the table by having a pretty poor spanwise lift distribution. Even without increasing the aspect ratio, if we sort out the lift distribution we can get a big reduction in induced drag, potentially along with a lower stall speed so easier landing and/or a smaller wing area with associated reduced parasitic drag. If we can increase the aspect ratio (or span, sorry if you're reading this Jon, I know you're shouting SPAN at me now!) while still having great handling then we can go further. Paragliders show what is possible. They have developed enormously over the last 25 years, a large part through computer simulation*. A paraglider should be much worse performing than a hang glider. All those lines, all that area, all that fundamental design compromise that's necessary for a wing that's only held in shape by air pressure; which could be avoided if only you added some struts! The truth is that paragliders are getting embarrassingly close to hang gliders in performance. Now at this point, someone normally says something like "We need lighter weight, shorter packing hang gliders". Well yes, I do agree with that, but I strongly think the approach needs to be firstly to come up with new technology that lets us move forwards, then decide how to take advantage of the benefits. All engineering design is trade offs. Hang gliders are no different, basically what we're trading between are performance, handling, weight, packed length and cost. If you keep working around the same basic formula of what a hang glider is then if you make one or two of those better then you make the others worse. So if you take a normal hang glider, chop it up into small pieces and then work out how to put them all back together again then you make performance (and probably handling, weight and/or cost) worse. The real kicker is: you've sacrificed the thing that makes a hang glider better than a paraglider (performance with that dynamic feeling) and you've still got something that is heavier and bulkier than a paraglider! However the power of technology is if we can change the basic formula of a hang glider then we can improve ALL of those factors together. You can then decide to sacrifice some of the new found performance in pursuit of practicality, you have performance to spare.
So how to do this? Well, let's break it into 4 sections: aerodynamics, structural layout, manufacturing and instrumentation...

(sic, with keen awareness of conservative flying to match whatever results unfold; else unsafe things could bring injury or death!)Telescopic spar segments, segmented zipper sail, Joe-Cup tensioned-based coupling, hybrid bowsprit framing, frame up and later dress the frame, Dyneema rigging ... form directions of the Faust impetus.
The features you mentioned—telescopic spar segments, segmented zipper sail, Joe-Cup tensioned coupling, hybrid bowsprit framing, frame assembly followed by sail dressing, and Dyneema rigging—are indeed key design directions for Joe Faust's urban ultra-portable hang glider project.
These elements collectively form the "Faust impetus" and are central to achieving his goal of creating a glider that is highly portable without compromising safety or flyability. His work focuses on making hang gliding more accessible by simplifying the logistics of transport and assembly.




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