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Forum Index : Windmills : NEW better Chinese blades, with our help.
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| domwild Guru  Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Gordon, Thanks for that. I knew there is a difference between uPVC and ABS. From what has been said in the forum in a discussion of PVC props, ABS seems to be a stronger material and perhaps better UV resistant. Regards, Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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GWatPE Senior Member  Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi Dom, the Namco chairs [stackable plastic chair with metal legs] in many schools are almost indestructable. The surface powders after many years UV exposure. The ABS is not as rigid as uPVC, but much tougher. Hi Glenn, 2m blades would be a bit long. I am not so sure of the broad tip either. I am a fan of a strong hub mount, as is available with traditional wooden blades. I would think that retro-fitting the PVC blades to the original chinese hub casting will require some adapter. The airfoil looks quite good, and the slotted tube mount will allow blade twisting. The use of a guide on the tube will lock the twist and aid in making identical copies. Gordon. become more energy aware |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Gordon, Thanks for that. Glenn, Minor point: If it is to be exported to the USA, then 25mm could present a problem, as an inch tube is 25.4mm and may not fit in. May have to make it one inch outer dia. and us metricated brothers may have to live with a bit of slack. Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
I might point out that the blade would be better if it was a tight fit on the tube. There is no way you could effectively fill any gaps. 0.4mm would not be a problem to slide pipe over, but would be hard to fill if sloppy. The moulding for the tube in the blade is not a full tube. There is a slot, running the length of the blade, visible in the pics. Gordon. become more energy aware |
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| Wes Lemarr Newbie  Joined: 07/09/2008 Location: United StatesPosts: 35 |
Gordon, When a 25mm tube is inserted into the blade it is quite tight, I will try to up-load a photo of the blade with the tube inserted tomorrow. The PVC blade “expands” when you push the steel tubing inside, in fact the PVC extrusion could accommodate tubing from about 23mm to 27mm. I will be happy to send you, or anyone who is instead a short sample (5 or 6 inches long) by post, just email me your mailing address wes@oemparts-express.com. Regards Wes LeMarr |
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| Wes Lemarr Newbie Joined: 07/09/2008 Location: United StatesPosts: 35 |
Hello Gordon, As promised here are a couple of photos of my Extruded PVC Blades with a 25 mm stainless steel tube inserted. Regards Wes LeMarr 
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| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi Wes, It appears that the tube distorts the airfoil section. How easily does the uPVC blade allow a twist? A tight fit is OK, but the tube you show seems to be quite a bit larger than designed for. This is evident by the gap between the airfoil skin and the tubing. Any riveting would create a depression in the skin. The correct tube will be a certain dia, and not necessarily a range from 23mm-27mm. I would prefer to see a complete blade with a flat mounting surface, rather than a tube arrangement. Gordon. become more energy aware |
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| Wes Lemarr Newbie Joined: 07/09/2008 Location: United StatesPosts: 35 |
Gordon, Thank you for pointing out that the blade doesn’t quite fit around the tubing, I never noticed that. I am planning to have another test run of extrusion made using a slightly softer grade of PVC which I hope will facilitate the twisting of the blade around the steel tubing. At the same time I will have the extrusion dye changed to make a better fit, as you can see the problem only exist on the top side of the extrusion. I really appreciate all of the members comments it is a great help in perfecting the product the saying is that “two heads is better than one” so 100 is currently better than one! Thanks again for your continued help. Wes LeMarr |
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MadRat Newbie Joined: 30/09/2008 Location: United StatesPosts: 21 |
Have you tested the design out yet as for actual performance? Go Huskers! |
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andrewf Newbie Joined: 24/12/2007 Location: New ZealandPosts: 15 |
With these blades, what sort of generator would be a good match? EVERYTHING SHOULD BE AS SIMPLE AS IT CAN, NOT SIMPLER - EINSTEIN |
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philb Regular Member  Joined: 05/07/2008 Location: United StatesPosts: 96 |
Hello everyone, I just got a sample of the blade by mail. I think it has great potential for homebuilders as well as for production. The curvature is just as Glen posted on the previous page. Robust leading edge and thin trailing edge. Sturdy. There is one small item I had not picked up until I got my hands on the blade. Notice in Glen's photo, there appears to be a line down the length of the blade, on the right side, where the rod is inserted. It's on the sample blade also. On my blades, that caused noise in normal operating mode. Not a lot, but some. I added more fiberglass to bring it to flush. The noise subsided somewhat. So, I added a .080 inch weed trimmer line at the same point and it made the blades barely audible above the wind. I'm definately not cutting down this well made blade, I like them. Thanks Wes. BTW, I wonder if I could order several sets in say, 8 foot lenghts?  I do realize they will not take the stresses without a few tweaks at that length.
You can email me at philb7369 at yahoo.com, if you prefer. philb |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Wes, Thanks for the sample. At one stage I would like to get an idea of the price inc. freight one can expect and what sort of lengths are being proposed for production. Happy New Year! Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Wes, Another point: To reduce cost, there might be a common length of the profile to fit most mills. Perhaps an uncogged 100 (rarer) or 80 or 60 F&P might be the yardstick for which a common length can be produced. Those with lower power requirements would then have to cut the prop a bit shorter - just a suggestion. On the other hand, the world market is bigger than the few F&P enthusiasts of Oz/Kiwiland. Cheers, Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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| Wes Lemarr Newbie Joined: 07/09/2008 Location: United StatesPosts: 35 |
Dom, I expect that we will have a distributor for the extruded PVC blades setup in Australia shortly probably by mid February 2009. This will enable us to ship the PVC blade extrusion in bulk by sea freight, saving a lot of freight & custom charges. The distributer will have a stock of the extrusion in long lengths & will be able to custom cut the blades to any length that is required. Best Regards Wes LeMarr |
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| GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127 |
Hi Wes, My main concern is with service life. PVC is not designed for applications with repetitive flexing, or light exposure. Presumably the slock lengths will be unpainted. Storage out of light will be essential. I am unsure about cracking of a stresssed form over time. A steel tube will help stop loss of a complete blade. Windmill blades will suffer extremes in temperature. Softening with heat may not be as much a problem as extremes of cold. Painting with UV resistant paint would be mandatory. You will need some legals look at disclaimers to be supplied with the product. Gordon. become more energy aware |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Is there a better material Wes could use to extrude these blades from. It would have to have the same sort of softening/melting characteristics as PVC to extrude properly. If we have a few suggesting Wes could ask the "extruder" if they would work. PVC is nice and rigid, we dont want something that will flop around. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Gordon, Well said! Bunnings sells a primer, which not only sticks to PVC, but also to tiles. I intend to try it on my uPVC pipe props first. I do not believe a UV resistant paint will stick to PVC unless a primer is applied first. A leading-edge helicopter tape might be an idea, too. Running my finger over the leading edge and other parts I noticed small ribs or protrusions; may need some sanding before painting to make it smoother. Sanding will help the primer to stick. Cheers, Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
At my day job we print a lot of PVC coreflute. The printers use a UV cured ink, and to make it stick the the PVC we wipe down the sheets with a rag dipped in Isopropyl alcohol. It cleans and changes the surface texture so ink ( or paint ) sticks. The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| bbsux Newbie Joined: 24/12/2010 Location: Posts: 1 |
Sorry to resurrect such an old thread but is there a way for us in the USA to get these blades? |
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