US Hawks Hang Gliding Association :: View topic - "Little Hawk"

The bamboo pole is 51 and 3/8 inches or 51.375 inches (a little over 4 feet).

The horizontal bamboo pole in the first shot spans 386 - 25 pixels, or 361 pixels over 51.375 inches. So dividing 51.375 by 361 pixels gives 0.142313019 inches per pixel in the horizontal direction.

The vertical bamboo pole in the second shot spans about 393-28 pixels or about 365 pixels (there is considerable grass ambiguity). This would be about a 1% difference, and since this is a larger estimate (because some of the grass was counted as pole to estimate its full length), then the value may be smaller and the 361 pixel value will be used in both x and y. That shows that the pixels are about square (and not rectangular), and even if they weren't, the estimate should be within a foot or so.

After turning the original into a red on blue image, a histogram shows 1920000 total pixels (1600x1200). The background (blue) contains 1457502 pixels, and the foreground (red) contains 462498 pixels. Together they sum to 1920000 which is the correct number of pixels.

So if we assume that each pixel is 0.142313019 x 0.142313019 = 0.020252995 square inches / pixel, that gives an area of 0.020252995 in/pix x 462498 pix = 9366.969855823 square inches. And 9366.969855823 square inches / (12x12=144) square inches / square foot = 65.048 square feet.

Author:	Bob Kuczewski [ Fri Sep 24, 2010 11:22 am ]
Post subject:	"Little Hawk" - Demonstration Glider
I've been thinking about building a small lightweight demonstration glider for a while now. The goal is something that pretty much looks and feels like a real glider but is smaller and lighter in weight so it can be taken to public areas and easily handled by non pilots with a little supervision. The size should be small enough so that it's not too hard to ground handle in moderate winds, and it should also support hanging people in a regular harness so they can see how comfortable it is (no "hanging on" required). Fortunately one of the Hawks members donated a glider just right for this project (thanks Dino!!). It's a small Moyes glider (around 130 squares) that I was told shouldn't be flown again, but it looks great. It's also got relatively small airfoil shaped down tubes which are comfortable to hold. At this point, I've cut the sail and sewn the lower surface together at the zipper, but it may have to be re-done to more properly fit the frame. This particular leading edge has multiple sections, so I've got some work there to pick the right parts to make it lightweight and convenient. Here are some diagrams and photos from the project so far: Attachment: cut_glider_small.png [ 18.48 KiB \| Viewed 21471 times ] Attachment: P9170068.JPG [ 51.29 KiB \| Viewed 21471 times ] Attachment: P9180075.JPG [ 42.69 KiB \| Viewed 21471 times ] Any thoughts and suggestions are welcome!!

Author:	Bob Kuczewski [ Mon Sep 27, 2010 10:45 pm ]
Post subject:	Re: Demonstration Glider
The previous photos were taken with the sail loosely fitted to the frame. Over the weekend, I got some great help from Mitch, and I should be able to start putting it all together in the next few days. This is an exciting project, and I can't wait to start putting this little glider into people's hands. In the past, we've used my full-sized Falcon 195 (featured at this 2009 fundraiser), and a lot of people enjoyed it: Attachment: Fundraiser.jpg [ 121.94 KiB \| Viewed 21453 times ] But it was relatively heavy for casual use and we were also worried about it getting away from people in any kind of wind. The smaller version will be much easier to handle and less of a concern with regard to mild winds. I'll post more pictures as I make progress.

Author:	SamKellner [ Tue Sep 28, 2010 6:39 am ]
Post subject:	Re: Demonstration Glider
Bob, Super job!!! Can't see how you get it all done. Thanks to all for supporting this project and the sport. Wish I was there to help. Great idea about that small glider. I have been trying to get permission to be in the local July 4th parade with my glider on the platform launch truck, but the parade committee says 'too wide". That small glider might be the answer. Oh to have a HG community here

Author:	Bob Kuczewski [ Tue Sep 28, 2010 11:10 am ]
Post subject:	Re: Demonstration Glider
SamKellner wrote: Super job!!! Can't see how you get it all done. Thanks to all for supporting this project and the sport. Wish I was there to help. I get it all done with the help of some good people like Dino who donated the glider, John H. who helped tremendously with his time (and his tools!), and Mitch who donated his time for the sail work. You're right that it helps to have a community. SamKellner wrote: Great idea about that small glider. I have been trying to get permission to be in the local July 4th parade with my glider on the platform launch truck, but the parade committee says 'too wide". That small glider might be the answer. Actually, the original idea came from a glider that Joe Greblo loaned me for the 2009 Kick Gas Festival: Attachment: Jay_2s.jpg [ 65.97 KiB \| Viewed 21443 times ] That glider was so small and light when packed up that it felt like a beach umbrella that I could tuck under my arm. The one I'm building now is a bit larger, but it's still small enough to fit inside my minivan so I can always have it with me. I made it larger than Joes with the hope that it might be able to lift off someone's shoulders when running into the wind. I learned that trick from Kenny who loves to have tourists do that with his glider at Torrey. They really enjoy it and it makes for great outreach for the sport. With regard to your parade, I think that's a great idea. All you need is an old glider that's no longer flight worthy and some time to do the work. I'll be posting some of my lessons learned when it's all done, and I hope that will make it easier for anyone else who wants to build one. SamKellner wrote: Oh to have a HG community here With your new club and your new forum, maybe you can start building one. If you become a USHPA chapter, then you'll be listed on their chapter roster for your state and that can help get the ball rolling as well. Mostly, thanks for being an early participant on this forum. It's been rough and I really appreciate those who are hanging in there with us. So thanks.

Author:	Bob Kuczewski [ Thu Oct 21, 2010 2:53 pm ]
Post subject:	Re: Demonstration Glider
Here's an update on the little glider after last weekend's work ... Let me start with a full picture of the glider in majiemae's living room: Attachment: File comment: Full Glider FullGliderc.JPG [ 23.47 KiB \| Viewed 21412 times ] Here's a picture of myself while making the crucial "point of no return" crossbar cuts: Attachment: File comment: Preparing to cut the crossbars CutCrossBar.JPG [ 28.56 KiB \| Viewed 21412 times ] Finally, here's a picture of majiemae wondering what she's gotten into: Attachment: File comment: A hang glider in my living room? majiemae.JPG [ 31.48 KiB \| Viewed 21412 times ] Overall, the project is coming along great. I've been going slow because it's always easier to cut too little too often than to cut too much ... even once!! One of the big problems was with the tip wands. They were very very stiff and they put tremendous stretch on the small sail when tensioned. I think with the larger (original) sail, there was more stretch and give (across a larger area) than on the smaller one. So I struggled with some way to get less force from the tip wands. Eventually I decided to visit a used sporting goods store ("Play it Again Sports") to look for either fishing rods or golf club shafts. It turns out that they had used drivers for less than $10 each, so I bought a couple with carbon fiber shafts. The diameter was too small for the tip wand cups, so I built them up by winding duct tape around the ends. Other than that, they ended up being perfect. They're lighter weight than the originals, and they take far less effort to tension. However, I wouldn't recommend them for anything that actually flies!!! Before I forget, I want to start listing my thanks to everyone who's helped ... I'll have to start with Dino who donated the original glider for this project. Thanks! Next would be Dave B. who helped transport it to San Diego. Just another thing Dave has done for the Hawks! Then there's John whose expertise, consultation, time, and ... tools were invaluable. Thanks John. One of the biggest contributors has been Mitch who donated hours and hours of his time for the sail work. A Big Thanks to Mitch!! A big thanks also goes to Stack who contributed some used Falcon frame parts that worked better than the originals. Then there's Margie who has helped in a hundred ways from the beginning of the project. Thanks for all that time! Finally, I've gotten help and advice from Ernie, and Chattaroy man, and several other Hawks along the way. Thanks to all the Torrey Hawks who've inspired me for the last 3 years! Well, that's it for now. Stay tuned for future progress...

US Hawks Hang Gliding Association https://ushawks.org:443/forum/

"Little Hawk" - Demonstration Glider https://ushawks.org:443/forum/viewtopic.php?f=4&t=83	Page 1 of 5

Author:	Bob Kuczewski [ Sat Oct 23, 2010 1:56 am ]
Post subject:	Re: "Little Hawk" - Demonstration Glider
Well, tonight I finally got to run with the glider. It was strung up with ropes (and not wire), but it was still pretty cool!! I started the day with a "legless" glider (no control bar or king post) ... Attachment: File comment: A Wing without Legs LittleHawk101022a.JPG [ 32.31 KiB \| Viewed 21391 times ] Throughout the day I found the static balance point ( ), cut the hole for the king post ( ), punched holes for the top wires ( ), installed the control frame ( ), and "strung it up" with some rope ( ) ... Attachment: File comment: Front view of "Little Hawk" LittleHawk101022b.JPG [ 27.93 KiB \| Viewed 21391 times ] Attachment: File comment: Top view of "Little Hawk" LittleHawk101022c.JPG [ 24.46 KiB \| Viewed 21391 times ] By the end of the night, I was running with it ... Attachment: File comment: First "flight" of Little Hawk LittleHawk101022d.JPG [ 20.1 KiB \| Viewed 21391 times ] ... and already using it as a demonstration!! ... Attachment: File comment: Your hands go here... LittleHawk101022e.JPG [ 18.75 KiB \| Viewed 21391 times ] Attachment: File comment: Little Hawk is lightweight and easy to handle!! LittleHawk101022f.JPG [ 25.58 KiB \| Viewed 21391 times ] The goal for this project was to create a small (about 50 square foot) glider that fits inside a minivan and is lightweight and easy to ground handle (for demonstration purposes) by people who've never touched a hang glider before. So far, it looks like all those goals will be met. The current glider still uses ropes (instead of wires), but after I do a little more refining, I think it will be ready to have a set of wires made. I decided to call the glider "Little Hawk" in honor of all the Hawks members who helped. I was originally going to name it after Dino for donating the glider. But then I got a bunch of help from John, followed by a really super session with Mitch. Then Stack contributed some frame parts and Margie helped with the construction. I can't even keep track of everyone who pitched in with a hand or a suggestion. So rather than call it "Little DinoJohnMitchStackMargieErnieSteveDave...", I went with "Little Hawk". But that doesn't diminish my thanks to everyone who helped. Maybe I can get you all to autograph the sail!! Attachment: File comment: THANKS!! LittleHawk101022g.JPG [ 23.71 KiB \| Viewed 21391 times ] THANKS to EVERYONE!!

Author:	JoeF [ Sat Oct 23, 2010 5:29 pm ]
Post subject:	Re: "Little Hawk" - Demonstration Glider
Long live and fly LITTLE HAWK !!! BobK, Consider going for HGMA certified Little Hawk version in carbon fibre for those who weigh less than 100 lb. Franchise such seriously throughout the world for such-weighted safety-aware people. The industry has perhaps underserved people of body weights less than 100 lb. You are onto something. Little Hawk 90 and Little Hawk 70. http://www.metacafe.com/watch/2136659/l ... o_gliding/ Flare handles can be an option per user. JoeF

Author:	Bob Kuczewski [ Sun Oct 24, 2010 12:18 am ]
Post subject:	Re: "Little Hawk" - Demonstration Glider
Hi Joe, At about 50 square feet for "Little Hawk", I think we might need to step up to a "not-so-little Hawk" to carry actual people. But, as always, I like the way you think, and there's probably a good market for something in the small-but-flyable range. As for this Little Hawk, I took it to Torrey today and had several pilots give it a try. Unfortunately, I didn't think to get everyone's picture, and I know that Larry L. took a turn and I didn't get it. Here are the ones I did capture ... Attachment: PA230175.JPG [ 17.47 KiB \| Viewed 21374 times ] Attachment: PA230176.JPG [ 28.27 KiB \| Viewed 21374 times ] Attachment: PA230180.JPG [ 40.05 KiB \| Viewed 21374 times ] Attachment: PA230181.JPG [ 25.92 KiB \| Viewed 21374 times ] Attachment: PA230183.JPG [ 28.61 KiB \| Viewed 21374 times ] Attachment: PA230185.JPG [ 26.55 KiB \| Viewed 21374 times ] From the looks of it, even seasoned pilots had fun playing with Little Hawk.

Author:	Bob Kuczewski [ Tue Oct 26, 2010 12:33 am ]
Post subject:	Re: "Little Hawk" - Demonstration Glider
Little Hawk Measures in at 65 square feet! I took Little Hawk out to Torrey again and tipped it up for some planform photos. I used a bamboo pole for "calibration" which I later measured to calculate the area. The top two photos show the bamboo pole used to calibrate for horizontal and vertical pixels. The lower two photos show isolation of the glider from the background and turning it into red and blue channels to facilitate the histogram. Attachment: LittleHawk_composite_ushawks.jpg [ 69.18 KiB \| Viewed 21359 times ] Here are the calculations from the original full size (1600x1200) images: Quote: The bamboo pole is 51 and 3/8 inches or 51.375 inches (a little over 4 feet). The horizontal bamboo pole in the first shot spans 386 - 25 pixels, or 361 pixels over 51.375 inches. So dividing 51.375 by 361 pixels gives 0.142313019 inches per pixel in the horizontal direction. The vertical bamboo pole in the second shot spans about 393-28 pixels or about 365 pixels (there is considerable grass ambiguity). This would be about a 1% difference, and since this is a larger estimate (because some of the grass was counted as pole to estimate its full length), then the value may be smaller and the 361 pixel value will be used in both x and y. That shows that the pixels are about square (and not rectangular), and even if they weren't, the estimate should be within a foot or so. After turning the original into a red on blue image, a histogram shows 1920000 total pixels (1600x1200). The background (blue) contains 1457502 pixels, and the foreground (red) contains 462498 pixels. Together they sum to 1920000 which is the correct number of pixels. So if we assume that each pixel is 0.142313019 x 0.142313019 = 0.020252995 square inches / pixel, that gives an area of 0.020252995 in/pix x 462498 pix = 9366.969855823 square inches. And 9366.969855823 square inches / (12x12=144) square inches / square foot = 65.048 square feet. I've been estimating between 40 and 70 square feet (often quoting 50) based on an estimated percentage of the wing that I'd cut off. So 65 is within that range. Of course, what good would it be to set up Little Hawk without having anyone run with it? Attachment: PA250044.JPG [ 22.36 KiB \| Viewed 21359 times ] Attachment: PA250046.JPG [ 21.52 KiB \| Viewed 21359 times ] Attachment: PA250048.JPG [ 15.06 KiB \| Viewed 21359 times ] Attachment: PA250049.JPG [ 16.15 KiB \| Viewed 21359 times ] Attachment: PA250051.JPG [ 17.76 KiB \| Viewed 21359 times ] P.S. I also flew my Falcon 195 for about 25 minutes (landing on top). I later hiked down to help one of our newest Torrey Hawks carry back up after the wind died. Another fun day for the Hawks at Torrey.

Page 1 of 5	All times are UTC - 8 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/