 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Windmills : Shhhhh! (We’re chinese blades)
Page 1 of 2   |
|||||
| Author | Message | ||||
| RossW Guru  Joined: 25/02/2006 Location: AustraliaPosts: 495 |
Thought I'd start another subject rather than divert the other one that started this thread. The story so far: I live on 22 acres on the edge of town, nearest neighbour is about 300m away, the next about 400, then any number from about 600-700m away. Last week, out of the blue, council turned up because they had had a noise complaint about our windmill! The environment dude likes the idea of windmills, and couldn't see the problem. Didn't think it was an issue, but had to act on the complaint anyway.... and it was at this point that I posted here looking for alternative blades. Anyhow, I decided that I'd pull the thing down and see what I could do... and a couple of things that did concern me immediately were the horrible way the blades were made. It's a 3m dia prop, the last 2 feet or so are cut back at an angle to make a smaller tip, but on thinking about it, the way they did it HAD to be a problem... The trailing edge was just cut off square, as was the very tip of the blade. so I into it with the 5" anglegrinder to re-shape the back of the blade. The initial roughing out left the new trailing edge more like an aerofoil but still pretty rough. Next morning, I went out and got a trailer tapered wheel bearing, and a flat-faced bearing for a trolley, a 3/4" bolt and some bits and made up an adaptor to mount the prop and hub on my engine crane. A very useful jig! I could now turn the prop to work on all sides, sand and shape. When I had the trailing edge fixed, looked closely at the leading edge and it had a horrible sharp front too, so sanded that back to a nice smooth aerofoil shape too, then sanded the entire blade set back with fine paper to get all the lumps and bumps out and painted it. Several coats, with wet-and-dry between. Then I wheeled it all into the garage (thankfully I have a big door and 3.6 metre ceiling! While it's hard to take a decent photo of a curved surface, the (nearly) finished blades now look like this - although I have to remove the bits of fluff collected on the leading edge. Balanced it as well as I could, then too it back up and put it back on and immediately she started to fly! Almost silently! There is still room for improvement, but from noise level readings I took back in october, to now, I have reduced it by over 20dB. In a 40kmh breeze now, 25 metres away, I'm seeing 51dB(A), which includes the sound of trees and things thrashing away. The turbine is audible, but not substantially over the background noise. So Glenn, and Trev, the urgent, burning need for new blades is gone, but the desire to try some GOOD blades and a new hub (thats actually centred, not offcentre like this PoS chinese thing) is certainly there. As soon as you two gentlemen can manage it, I'll be in like Flynn! RossW |
||||
| adelaide Regular Member  Joined: 24/03/2006 Location: AustraliaPosts: 46 |
cool any peformance difrence w? notacible? help to make progres or radio and vitamin b |
||||
mrpackethead Newbie  Joined: 11/11/2006 Location: New ZealandPosts: 17 |
Hi Ross, I'm just working my chinese origin pos as well. My blades are 2.55m in diameter, and i did lots of work to get them quieter, by shaping all the edges up. My blades don't ahve the tapered ends though.. Mine are straight for the whole length. I'm thinking that performance wise they should run better, as there is less drag, but not sure. Every thing should be as simple as possible. Not simpler. |
||||
| RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495 |
I have not done any quantitive tests, but so far it seems that they run faster in a given breeze, so I believe they should be better performing than they were. |
||||
Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5116 |
Does anyone know if these extruded fibreglass blades are available for purchase anywhere in Australia? I would like to get hold of a set and see if we can make a few modifications to get quiet better performing blades. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| mrpackethead Newbie Joined: 11/11/2006 Location: New ZealandPosts: 17 |
I can give you some contacts for buying them ex-china.. I've found a supply.. And they are CHEAP. Every thing should be as simple as possible. Not simpler. |
||||
| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5116 |
Yep very interrested. They should be strong, will take a lot of flexing before breaking, and I think if I sit down and work out the exact angles, I should be able to come up with a cut line that will give the correct twist. This would be along the leading edge, and then it will be just a matter of rounding off the cut line, plus clean up the trailing edge like Ross did. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
Pt w/field Matt Senior Member  Joined: 24/02/2006 Location: AustraliaPosts: 105 |
hi try ebay in the solar panel/electronics section and oatley has hubs for under 50 including post matt down south |
||||
| dwyer Guru Joined: 19/09/2005 Location: AustraliaPosts: 574 |
|
||||
| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Interesting blades but they look like no twist, no taper ones to me. Interesting story, too. Boo to the dauber-inner! May he rot in a globally-warmed up hell! * Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
||||
Robert_VK2BBR Regular Member Joined: 31/12/2006 Location: AustraliaPosts: 67 |
I am interested in the contact for these blades please robert 1555 W grid connect system since Jan 08 both vehicles running on modified, used vege oil. |
||||
Highlander Senior Member Joined: 03/10/2006 Location: AustraliaPosts: 266 |
I think this is what you guys are looking for, post results if you get some answers. http://www.alibaba.com/productsearch/wind_turbine.html Central Victorian highlands |
||||
Chris Senior Member Joined: 12/09/2005 Location: AustraliaPosts: 146 |
Hey mrpackethead, think you can set me up with those contacts too? I dont have time to make my own set of blades... Thanks mate |
||||
| dwyer Guru Joined: 19/09/2005 Location: AustraliaPosts: 574 |
Hey mrpackethead, Where are you now and and still waiting for your replied over the blades as i dont have time to make my own set of blades since i ask you on 10 of Jan and also l have been waiting for sheetmetal company to cut and roll slainless steel sheet for my comming Lenz since just before Dec 2006 and he is bloody hopeless 
dwyer the bushman |
||||
| mrpackethead Newbie Joined: 11/11/2006 Location: New ZealandPosts: 17 |
The china supply line is a bit complex, and unless you are in the importing game, you might want to give it a miss. If you do, following the link above at alibaba. However for NZ$125.00+Freight, Micheal Lawley at Ecoinnovation is selling sets of the fibreglass blades. http://www.ecoinnovation.co.nz/product_detail.php?id=210 Note: I've got nothing to do with ecoinnovation, other than i've bought a few bits and peices off them in the past. Every thing should be as simple as possible. Not simpler. |
||||
| Highlander Senior Member Joined: 03/10/2006 Location: AustraliaPosts: 266 |
Hey fellas, click on this link http://www.alibaba.com/productsearch/wind_turbine.html This has direct links to the Chinese manufacturers, they probably will not sell 1 set but if you get a price on 10 sets, they may want to do it, I don't know what their minimun is. Send them an email and see what happens Central Victorian highlands |
||||
| Robert_VK2BBR Regular Member Joined: 31/12/2006 Location: AustraliaPosts: 67 |
Has anyone used or have experience with these blades from ecoinovation. Are they twisted aerofoil type design? thanks robert 1555 W grid connect system since Jan 08 both vehicles running on modified, used vege oil. |
||||
| petanque don Senior Member Joined: 02/08/2006 Location: AustraliaPosts: 212 |
I must admit I have been surprised at how noisy the Chinese windmills can be. Personally I would find the noise from a Chinese wind mill intrusive near my house even if it was mine. Sounds like you have made a considerable difference to the noise output I would thin there could be a niche market for an importer who knows how to debug the Chinese product and get the specifications up to what would be acceptable to Australian customers. Alternatively there could be manufacturers in China that make a reasonable quality product. After all even the premium brands of shoes are made in China these days. Many of the household electrical goods such as TVs can be made in China and still have acceptable quality. |
||||
Trev Guru Joined: 15/07/2006 Location: AustraliaPosts: 676 |
Ok fella's, I supplied the set to Glenn. I have kept quiet because I don't like them. Glenn's purpose was to look at improving the performance and noise level, to help those who have these machines. These blades are rough, straight, not tapered, no twist and very noisy. They are narrow and therefore need reasonable wind to get them to start up. On the machine with the standard hub, there are areas that are in drag, which means there is only part of the blade that is actually working and part of the blade trying to hold it back. The wind flow is disturbed considerably across the curve that they have, in parts the wind actually reverses in flow. My opinion at this stage is to wait and see what Glenn can do and compare the performance on the F&P windmills. I can supply a set for $120 + freight. My F/g Composite Blades http://www.thebackshed.com/Windmill/Trev/Trev1.aspare more expensive but I can't say enough that do do perform , even in light wind. And they are not noisy. When Dennis Latham was up here with his PVC blades, I had 2 days comparing the blades. I don't mean to be horrible, Dennis is a nice fellow, but the blades were disasterous. Dennis noted a strong whirly hit my large blade turbine, screwed the blades and clipped the pole, no damage done at all. PVC is not a safe material, they would have shattered. Future editions of these long blades will have more strength built in. I believe Dennis is now in the process of copying to some degree my blades, because they work. Glenn, is it possible to put the video clip on the web. If you want electric power then you need something that will extract the energy from the wind to produce that electricity. I have seen it over and over. Buy something CHEAP and thats exactly what you get. But in the long run, after you work out they don't work as good as you would like, then you go buy something else. The extra expense, over several purchases, mounts up. I supplied Glenn with some composite foam also for the attempt to use his CNC router to produce a plug for the Aerofoil blades. Still no dates at this stage but we are working on it. May you all make wise choices. When there are 100's of wind turbines with poor performance, the Gov't has every excuse to go Nuclear. Trev @ drivebynature.com |
||||
| RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495 |
Glenn and Trev, particularly.. This thread was started basically, because of a noise complaint about my mill. While the complaint has been dropped (seems it was vexatious - I sent a pair of door to door godsellers packing and they didn't like it) My attempts at silencing (well, quieting) my blades were spectacularly sucessful. Over the weekend, we again had winds over 50kmh and while the mill does make noise, it was substantially below the noise of the wind in the trees 200m away. My work wasn't optimum, and I'm sure if I sanded them back more, and painted them properly, and wet-and-dry finished them and waxed them they would be even better. However, your points are completely valid Trev - these blades have no twist. Mine are off the "3 metre" chinese turbine, and have the trailing edge cut back for about the last 18" or so. The re-shaping was surprisingly easy, roughed it out with the 5" angle grinder and finished it with sandpaper by hand. Seeing the difference this made has given me real hope. I made nearly 20 KWH this weekend from my little mill! While I had the prop and blades down, I discovered that the PoS is badly machined - looks like about 2mm off centre, which makes it impossible to balance. I'm definately very interested in a set of blades with a proper profile and twist, and a hub (my generator has a tapered shaft with a key, rather than a spline). I'll be really keen to see one of your new prop sets! Roughly speaking, Trev, is a tapered/keyed hub a problem? In terms of power available, Density of 25.0C dry air at 310 metres is 1.139 Kg/m^3 If I then use that density to calculate power available: 86.3W possible from 3m dia prop (7.1 m^2) at 10 km/Hr 2329.6W possible from 3m dia prop (7.1 m^2) at 30 km/Hr Assuming a coefficient of performance of 0.35 (which seems to be "good" for wind turbines, the theoretical limit is 0.59), and a reasonably efficient generator at 80%, I would expect electrical output to be: 24.2 watts at 10kmh and 652.3 watts at 30kmh. My prop can't be too bad, as I've been seeing not far short of these figures with my current setup. |
||||
| Page 1 of 2 |
|||||
 Print this page |
 |
The Back Shed's forum code is written, and hosted, in Australia. | © JAQ Software 2025 |
