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Forum Index : Windmills : my new blades
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brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
a couple pics of the progress I'm making with my new blades Bushboy |
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brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Here's the twist , the top pic was the "art" blades, not supposed to post that . Bushboy |
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adelaide Regular Member Joined: 24/03/2006 Location: AustraliaPosts: 46 |
well done cant weight to hear some results? help to make progres or radio and vitamin b |
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Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Hey Bruce Thats a big windmill, good to see you finally finished those blades. Very interrested to see how it goes, big blades and a 1:2 drive on a F&P, might just work. Love the hat. Glenn. The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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mink Newbie Joined: 20/04/2006 Location: AustraliaPosts: 3 |
Hi Bruce Been watching your handywork for a long time now, and as always the thing looks great. Why did you opt for that tip shape? I saw something recently that said that shape (with more rounding) would lower noise and improve efficiency. However, by the shape of the blades your'e obviously going for a TSR of maybe 6 or something? where noise is'nt going to be an issue. Just interested in your thinking there. Also what shape are the neo's you used, and where did you buy them? Was it difficult to remove/fit them, and was it a worthwhile exercise? Mink |
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brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Hello Mink. the tip shape I got from a posting I read about a long time ago -must dig up the details,but basically it went opposite to Hugh Piggots design-straight leading edge and the taper on the trailing edge. I have a full50mm drop in the chord width at the hub ,tapering to nothing at the tip ,blade is around 1700 mm length. Have a look at the postings on this site for "Matt Lyons" ,he bought the neo's up to my place at Mt.Tamborine and we retrofitted then one evening-a bit tricky but he showed me how to do it . I'd say they definately are an improvement on the ceramics,but the cogging is still there.I've seen 800 watts out of the .6mm stator,and that was screaming,flat out. On a heavier wire stator ,I really think 1Kw is quite possible,we'll see. No wind here for the last 10 days- Bruce Bushboy |
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Chris Senior Member Joined: 12/09/2005 Location: AustraliaPosts: 146 |
I havnt seen matt here in a while, whered he go? |
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brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Hi Chris, I telephoned him some time back and he was working on CBD Melb. highrise installing a few VAWT's with F&P motors for some engineering Co. Sort of working for his hobby .but getting paid for it. He has bought a acerage property south of melb. , so maybe he is working on this also. Bruce Bushboy |
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Saaremaa Newbie Joined: 10/12/2005 Location: AustraliaPosts: 13 |
Excellent work with those blades Bruce. They look light and efficient. Your work on these projects so far has been exemplary. Blade design seems to be an art and a science. There are so many designs around that it is confusing for a novice to make a choice about which shape to begin with. And there's also a lot of choice involved in the materials that they can or should be made from. And again in the way in which they are made - handcrafted, made on a jig, poured into a mould etc etc. While doing extensive websurfin on the subject I've found this brilliant webpage - set up by a doctor of engineering who seems very focussed on model airplanes. In true German fashion - he focusses down to the finest detail of design. He has set up an online java script which you can design your own airfoil shapes with. It's quite a vast site so you have to spend a bit of time working out what's what. see: http://www.mh-aerotools.de/airfoils/
Judging by the variety of blades around various websites - for me it's been easy to get the impression that any old shape would do . Notice that he has a special section on 'Other airfoils' . This shows that there certain profiles which are optimised for use with wind generators - and that to get the most power out of the wind - you can't use just any old shape.
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