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Forum Index : Other Stuff : High altitude kites
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Revlac Guru  Joined: 31/12/2016 Location: AustraliaPosts: 1023 |
I like your winch build Bob. http://kitesite.com.au/kiterecord/Winch.html very nice.  I would have made a link for it, but it is still http and not https so not sure if it would still work.. Cheers Aaron Off The Grid |
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droceretik Newbie  Joined: 24/01/2018 Location: AustraliaPosts: 17 |
Thanks Klaus and Aaron. You can see YouTube videos of the 2007, 2009, 2010, 2011, 2012 and 2014 series. https://www.youtube.com/watch?v=-VE6Fdd0jnk&t=298s https://www.youtube.com/watch?v=Do8L6nfQn1U&t=28s https://www.youtube.com/watch?v=HqJTH4an4qc&t=368s https://www.youtube.com/watch?v=gCQO23QtOZ4&t=15s https://www.youtube.com/watch?v=0l7m5v94tvw&t=340s https://www.youtube.com/watch?v=IG_Y9ESbS4c&t=114s Some of those videos show show the launches. The trailer is turned so the rear is facing away from the wind, The wheels are chocked to prevent the kite towing the trailer. If the ground wind is marginal, that is, not strong enough to launch the kite on a line length of 100 metres, then line is played out to 200 or even 300 metres. The kite is then launched and counter winched into the wind. The difficulty is when the wind is just enough to sustain altitude. In these conditions any line release will result in the kite dropping. The skill comes with line release, stop, line release stop or even say release 50 metres and rewind 30. The kite will then rise in a zig zag pattern shown on the Web sites techniques page.http://kitesite.com.au/kiterecord/Techniques.html The shape was copied from a previous design and the original was a French Military kite or Conyne Kite from the 1st world war. In the 70's it evolved into the Conyne Delta, then the Dunton/Taylor Delta and finally with a few tweaks, our version. Essentially it is a Delta kite with a triangular box section. This gives great lift, high flying angles, strength and stability. The front panels of the triangular box provide a keel effect so that no "tail" is required. We did attach a small drogue or drag sock to prevent overflying, that is, to prevent it from going past the vertical. The kite weighs 3 kg in the single spreader version without instruments and 3.7 kg in double spreader version with instruments. The wind never stays in the same direction from ground to high altitude. The trailer is turned so the line exits straight out the line guide. You can see the the wind properties on the graphs on the web site page. http://kitesite.com.au/kiterecord/Wind.html http://kitesite.com.au/kiterecord/Kites.html The line at maximum altitude was 15 degrees from horizontal and the kites angle was 25 degrees. We measure line angle with a gauge attached to the line guide and the GPS kite altitude and position tells us the angle which we can calculate using trigonometry. We estimate that we could have gone about another 600 metres (2,000 ft) higher if we had another 1,500 metres more line on the reel. As if 12,400 metres wasn't enough! The maximum pull was 122 lbs. You can see the hydraulic tension gauge on the videos and the web site. It was built by an engineer/kite enthusiast, Doug La Rok in the USA. I recently changed the gauge from 200 to 2,000 lbs. I am contemplating attaching load cells to the kite and at the trailer to measure line tension and transmit to telemetry to record. I built the winch through many versions and while not quite to professional standards, did the job. With improved kites we expect 150 lbs for our next flights and up to 500 lbs for a kite train which will require big mods to the winch and power supply. Ask any questions, I am happy to answer them. Bob |
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| droceretik Newbie Joined: 24/01/2018 Location: AustraliaPosts: 17 |
This image is the second hand test machine used in the footwear industry. I haven't used it to test lines yet as I need to make some special fittings and clamps. The gauge tests to about 50 lbs but I may be able to rig up some lever, ger or pulley system to increase the ratio by 4 or so to test 200 lb lines.  This is the line test rig I made from a boat hand winch and the hydraulic tension gauge that Doug La Rok (USA) made. It will have to go back on the trailer to measure line tension during kite flights. It would be nice to have a spare. I may approach Nick, my son to copy this one. He is a fitter/machinist. You may notice the gauge on the right in the lower image which I got to up the capacity for the anticipated train flights in a few? years. Sorry about the quality of the images. I had inadvertently set the quality to low on my cheap camera.   Lots of hobbies require ingenuity to find solutions. Bob |
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| Jarbar Senior Member  Joined: 03/02/2008 Location: AustraliaPosts: 224 |
Highly inspiring Bob, thanks for all the video links and info. Perseverance pays off. Anthony "Creativity is detirmined by the way you hold your tounge".My Father "Your generation will have to correct the problems made by mine".My Grandfather. |
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| droceretik Newbie Joined: 24/01/2018 Location: AustraliaPosts: 17 |
Thanks Anthony, I am a fan of Lawrence Hargrave who is one of our greatest pioneer inventors. He invented the Hargrave Box kite which the Wright Brothers copied the wing design to make their first plane. He always believed strongly in sharing his discoveries and did not patent anything. He also invented a rotary engine. He was probably one of our earliest "back shed" boys. One of my team members, Mike Richards recons I share too much especially to other kite builders who are contemplating the world altitude record as well. Maybe he is right but I just can't "shut up". I have a few developments in preparation for the world record attempts next year. A new flying site will be Bulgoo station, west of Cobar. It is a 103,000 hectare sheep station. That's 206,000 football fields. yeah, it's the nerd in me! I have new sponsorship from a Japanese company, Toyobo with supply of high strength IZANAS fibre to Tasline in New Zealand, a line braiding company. There is no financial sponsorship from any companies, just UHMWPE fibre product and braiding by Tasline but it is worth a fair bit. Hopefully I can get enough fibre to make 20,000 metres to replace worn line from the previous record attempts. The DSM Dyneema product sponsorship was 32,000 metres of line worth about $15,000 retail in 2009. Nothing to sneeze at. Other funding is slowly building up with GoFundMe and Facebook. I'm about to contact TECO to get some detailed specs on their electric motors in respect to startup and running torque. I use 1.5 kw single phase inverter/controller combinations. Terrific robust products. I have an 0.72 kw motor I want to use in tandem with the 1.5 kw motor. Should be OK with the larger kite and 25% increased line tension from 122 lbs to 160 lbs. I have some GPS telemetry systems being assembled by my electronics guru, Keith Rippon in Sydney. Another broken system was sent to the USA for repair or replacement. catch you guys and you girls? later. Bob Moore |
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