10-30-10, 04:51 PM | #11 |
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OK Patrick, some pointers if I may.
Your foil shape is not bad, but you need to move the thickest part of the blade towards the trailing edge, and it needs to be thinner at the tip, also round the transition from the upwind side to the downwind side at the leading edge, that will reduce the turbulence there. Washout or twist is vital, the blade will turn in the wind at 10 degrees, but will never "fly" My blades used to spin at a speed that "filled the circle" ie in theory no wind passed through the disk covered by the blade without imparting its energy to the blade. Your blade looks better than my early efforts, so good on you. Suggest you will be happier with a permanent magnet motor than with an off the shelf alternator. |
10-30-10, 05:16 PM | #12 |
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Thanks Nibs. I might be able to move the thickest part back by adjusting my router, but I don't know how I could get any twist while using a table saw to cut the blade. Also, I should be able to round the lower portion of the leading edge some which would make the effective angle of attack lower also.
I read about Bergey wind turbines using "pultruded" fiberglass blades that were the same chord the whole length and had no twist. They claim that they perform well, so I thought I could get away with something like that, only made out of wood (which is cheap and I have lots of) and using power wood working tools (that I already have). Low to no cost, just some time to figure it out and make them up. |
10-31-10, 04:56 PM | #13 | |
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Quote:
Whisper used to use two blades but most of those machines shook them selves appart and went flying off their towers. Simple Wind Turbine Blades is a rather good blade design, these machines tend to work and hold up pretty well. |
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10-31-10, 06:48 PM | #14 |
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I bought a 400W HAWT on Ebay. It has the plastic blades. A few photos are attached. I think the airfoil shape, at least at the tip, looks remarkably similar to the ones I made. Of course the chord is a lot less and they have twist and taper that mine don't. Both the leading and trailing edges are sharp all the way down. This particular turbine uses 6 of these blades bolted to a steel hub powering a modified GM 10SI alternator PMA. Total rotor diameter is 60".
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11-03-10, 06:32 AM | #15 |
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Ive just read you're posts and was wondering if these wooden blades would work with the generator I'm going to make. If the weight would have any effect. The easiest way to is to give you a web address and say I have bought two of these F&P washing machine motors to build my wind gen for $40 auzz. its http://thebackshed.com , let me know what you think .click homegrown then Projects and info- F&P smartdrive. This is the actual motor that drives the washing machine, pull it apart rewire and you have a generator, up to 3oow
Last edited by OutbackAuzz; 12-01-10 at 07:35 PM.. Reason: added links |
11-03-10, 09:07 AM | #16 | |
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Quote:
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11-03-10, 12:58 PM | #17 |
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OK, I made up a quick and (very) dirty pivot for the propeller. I made a video and uploaded it to YouTube (my first one, yeah!). Comments appreciated. Here's the linky:
Last edited by Patrick; 12-04-10 at 02:31 PM.. |
11-03-10, 08:22 PM | #18 |
Journeyman EcoRenovator
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I lolled. I would have laughed harder if you had saved some signs from the Nader or Gore campaigns.
Patrick, how do you plan to test the performance of your blades vs. other designs? |
11-03-10, 08:53 PM | #19 |
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I think I'll set up the Hornet HAWT I bought on Ebay, then switch out the blades for the wood and see how it does.
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11-25-10, 10:44 PM | #20 |
Helper EcoRenovator
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Haha that is awesome!
Perfect music choice!
This is cool, I'm inspired to make my own table saw/router blades. Regarding the angles that nibs mentioned I wonder if you could cut the blades into thirds and pin them with dowels at varying angles... Or if it would just fly apart into pieces |
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