Assorted Dragonfly Projects
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These are pictures of some Dragonflys, Dragonfly clones, & associated projects.



Chile

Arica Chile

Eduardo Monzon's wind test site on the Chilean coast, (link in Spanish) Eduardo has problems with the local authorities who promised grant money but never delivered, others want a free piece of the action for permits. Something needs to be done there, because they kill startups, which are hard enough anyhow, and everybody looses. Suggestions please contact Dragonflypower




Benson, AZ

It's 23' to the axle, but its on a ridge that is 20' above the surrounding valley, and the blade dia is right at 9'. it's made out of junk and scraps that i've collected over the years. I saw the blade idea on the computer. the guy used abs, but living in az I knew it doesn't hold up to the sun, and I think this green sewer pipe will hold up better than regular pvc. I just cut the pipe into four equal lengths, then I realized that I could use one as a template for the other three. the design is mine, so they will probably fail at some point, but live and learn.

the tilt pole worked out better than i hoped. this was the most welding i've ever done; fingers still crossed, i just got it up yesterday. let you know about the output when i get it hooked up, if you want . we're on a tight budget here, so it's one thing at a time. oh, and i suspect that i'll change out the spring for a pneumatic screen door closer. i wasn't true to the plans, but i appreciate the knowledge.....hell, i was stuck on how i was going to stop the cord from getting wound up in the pole. money well spent....thank you.

Paul Robinson

wolfturbine




Manchester, CA

A 4 blade Dragonfly on the Garcia river, 2 miles from the Pacific Ocean. It ran lights and radio for 2 large Geodesic domes, worked continually and was totally neglected for up to 2 years at a time.

4 blade designs are easy to balance, but not as strong as 3 blades. Four also produce more drag because they have more trailing edges.

Manchester



Th' Deep Woods, Mendocino, CA

An electric wheelbarrow using a motorcycle rear fork. Based on an oriental, medieval design with a large cart wheel for uneven terrain. It only has one speed, the power is from a ford starter. Electric Wheelbarrow
The small person is a Mendocino Pygmy placing a spell on her moms' horse.





This isn't a Dragonfly project but it's so cool I have to link. Rikimbili (also spelled Riquimbili): A term coined in Cuba to describe a certain kind of DIY motor powered 2 wheeled vehicle that started their life as bicycles.



A power generating exercise bike design from one of Michael Hackleman's books. Construction and photo courtesy of Napoleon Molina.
Bike generator


Wood Feathering Armature
This Dragonfly had a wooden feathering carriage as a test bed for attachment configurations of the spring, automatic field switch, and wiring. It worked fine but in the opinion of the builder, (me) it looked flaky, like a bunch of wood blocks, randomly glued and bolted together. Later designs used iron, because it looks more durable, but sealed hardwood works quite well.


Another turntable design A Dragonfly turntable with modified brushes, and blade mount with adjustable pitch. My opinion is that both modifications look well done, but are unnecessary complications. For the pitch adjustment to be practical, the twist taper should be adjustable also. I've never had problems with the existing brush configuration, and it's much simpler.

A lot of innovation has taken place since 1980, and home windpower techie's naturally draw on state-of-the-art designs, not only for the sake of wresting the last drop of available energy out of a given slice of air, but also because that demographic has developed like race car or computer tech, where it's bad form to be represented by anything but the newest and best (good luck). I kind of object to that because it takes on a competitive fad nature, where shiny new today looses half it's value in 3 months. Also the buyer's stuck with finding replacement parts which definitely and absolutely will go out of production given fad marketing. My humble advice is KISS: (keep it simple sir).


old 2 Blade
This is one of my first. The long narrow vane responded slowly and wandered some. A more responsive tail has a vertical vane with a sloping front edge, like a sailboat jib. This machines' 6 foot blade was mounted directly on the alternator, but the pitch couldn't be cut shallow enough to match the rpms needed. At the time I chose to use a step up pulley to get the rpms, rather than a modified alternator, because I didn't know anything about wrapping field wire. Ed Lenz recommends making an alternator from plywood, to match the blades' power curve, a good idea if it doesn't overheat.


DIY Malawian wind generator
William Kamkwamba's blog


Colombia



Maquina eolico "La Parina" y Napoleon Molina, with friends. Colombia.

La Parina is the name used in South America instead of "Dragonfly" because a friend suggested sometimes rural folk are superstitious about names and it could discourage sales.




iron Blade 1

Sometimes people are inspired to use big fan blades because the work of making them is already done. Anyone planning this should be advised that they don't work too well because fans are made to put energy into the air (a propeller), it's main regard to efficiency is the cost of production, so they work about 1/3 as well as one designed to pull energy out of the wind (a turbine). They're heavy, and metal fatigues, so they're also dangerous especially if they've been salvaged. This one looks about 3 or 4 feet across (less than 1/3rd the area needed for what appears to be a 35a delco) with a 14 inch drive pulley. The broad width of each individual blade puts the porosity ratio high so that most wind will go around the plane of the blades as though it were a solid disk, unless it turns slowly, so it looses efficiency in higher wind.

Small diameter, large pulley, no airfoil or twist taper, will put the output threshold above 20 mph. unless the field requirements are minuscule, but then the total output will be also. Don't do it


iron blade bearings

A good bearing arrangement.





Some turbine design discoveries:

  • Low drag design copied from Wright Whale's flipper

    click for link


  • Noise of conventional helicopter blades comes from turbulence produced by mini-tornados rolling off the tip of the blade. Darpa's solution for blade noise: the Silent Hawk. This is just an artists opinion however & the inset looks more like an Apache.
    From Wired magazine



  • Hot wire airfoils Hot wire foam cutting rig using Stainless Steel fishing wire for RC airplanes. Should be reinforced for turbine blade cores. List of materials in the link: Youtube Video


  • Vertical axis field placement can produce 10x more power per sq meter. (Physorg.com)
    A paper describing the findings -- the results of field tests conducted by John Dabiri, Caltech professor of aeronautics and bioengineering, and colleagues during the summer of 2010 -- appears in the July issue of the Journal of Renewable and Sustainable Energy.


  • Vortex A new kind of wind turbine being developed has no blades, captures energy from structural vibrations caused by wind vortex
    1 (Wired.com)
    2 (Gizmag)


  • Owl-inspired wing design reduces wind turbine noise by 10 decibels (Science News)


  • Dragonfly Wing Mimic produces 35% more power (Seeker). Link to the original study (royalsocietypublishing).

  • Flapping Wind Generator mimics wings (Gizmag)




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