 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 : Power of the wind
| Author | Message | ||||
| VK4AYQ Guru  Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi all, You may or may not have followed my entries on the OEM mill I set up more than 12 months ago it has been chugging away in low winds until yesterday, we had the storm cell that hit Brisbane and did so much damage, the wind gusts on my little wind recorder showed 60 MS with a wind component average of 41 MS during the event which lasted for one hour or so. The OEM mill survived the wind and furled reasonably well but the mast a 2 inch OD steel pipe was bent back around 20 degrees from the force of the wind on the furled mill. there are no shorting devices on the mill so it relied on furling for survival. In the gentle breeze today the mill was spinning with no apparent damage either mechanically or electrically, but due to the bent mast it didnt track the wind. so next project is to pull it down and inspect for internal damage not expecting any as it is still spinning and generating. Fun and games with wind power. My old mill a 500 watt Chinese mill is still up and running but did stretch the guy wires a bit, no furling it just went fast, a quick look showed the amp meter pegged at 50 amps, all for fun. All the best Bob Foolin Around |
||||
Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Wow Bob, thats a bit of wind! Yeah there have been a few wild storm cells in the area the last few days. I shut down my mill by pulling it into furl and shorting it out. I dont trust my tower yet  , it needs some more guy wires about half way up.
Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
||||
| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Glenn The mast bent above the top guy wire attachment which where at the length of the blade down the mast, the wind bent it when furled, I believe just on the wind drag on the furled machine alone caused the damage as prior to that it was furling fully at around 20 MS. It is still working happily in the wind today when the wind comes from the S.E. so no mechanical or electrical damage, amazing, it shows ho tough these little machines are. After seeing this I can understand your need for wires in the middle of the mast, mine is embedded into the shed to 17 ft then six feet to the guy wires above the shed then 5 foot six inches to the mill centre above the guy wires. I think that my increasing the diameter to ten foot on the blades contributed to the total drag area of the mill causing the bend. When I pull it down for repair I will sleeve the bast with a larger pipe and hope foe lessor wind velocities in the future. All the best Bob Foolin Around |
||||
| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi All Here is some pics of the OEM with bent mast and the old mill still running. 
The old mill is still up and running, it uses a slightly larger pipe for the top of the mast. 
All the best Bob Foolin Around |
||||
fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
Hi Bob, Good to see it survived the wind event relatively unscathed, by the looks you have the guy wires attached to the top tower flange. My advise to all who have bought one of these and have done the mods, especially with extending the blades is to weld on guy wire anchor points as close as possible to the blade dia arc. As you have said it is only 50mm and it needs all the support it can get . I would think a man of your ability will have it all fixed and upright in no time. As you have said "Fun and Games" with wind power , Mother Nature will always find the weak point. PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
||||
| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
High Phill The attach points are just outside the blade radius and about a foot up from the original joiner flange, which was cut off and the pipe was slipped inside the two inch mast pipe. I think I will make a hinge joint there when I take it down as it would be easier to work on if I can lay it down, also it would make the top pipe stronger. I think if it had standard blades it wouldn't have bent as the extended blades give double the swept area of the original. Like all things modified it finds another problem to deal with. It is a lot more interesting than solar panels, they are just boring and efficient. All the best Bob Foolin Around |
||||
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Not so if you mount the panels on a tracker  .
It kept me busy well over a year to design & build my additional 2 trackers from scratch. You are right about solar efficiency, my battery bank is full by morning tea time on any sunny morning. The trackers then supply enough additional power to run the house during the day so there's no drain on the battery bank while the sun hits the 6 panels. Klaus |
||||
isaiah Guru Joined: 25/12/2009 Location: United StatesPosts: 303 |
That's a neat new angle of attack Bob !'  '
Isaiah URL=http://www.motherearthnews.com/Renewable-Energy/1973-11- 01/The-Plowboy-Interview.aspx>The Plowboy Interview[/URL> |
||||
| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Tinker You are right about the trackers giving you pleasure making and watching them perform on a daily basis, I was going to go that way as I would have got around 30% more power out of the panels, but on the suggestion of Gordon I went for fixed panels as this is a building code 65 MS region and I would have had to build the trackers like a bulldozer to withstand that. I went over to a guy I know who has a 5KW array on trackers, his big one was blown to bits and panels spread around his yard waiting for an inspection by the insurance company ,  his smaller trackers with four panels where more or less intact, so he is still on limited power.
Being on the top of a rise and in the turbulence area of several small hills the turbulence was unreal, looking out the window during the storm was like looking into a washing machine the wind was ripping the tops off the trees, and flattened the shade house and tore the caravan annexe to bits. One day when i run out of things to do I will do a tracker just for the hell of it, but now there is enough to keep me busy. All the best Bob  Foolin Around |
||||
| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Isaiah It is a real casual mill as it shows a lay back attitude, actually I think it was trying to capture the down drafts
All the best Bob Foolin Around |
||||
Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Its a "Half Mast" mill, half way a Hawt and half a Vawt. You were lucky it didnt bend right over, as it then would have been a Helicopter and lifted the roof off the shed. But more seriously you were lucky it did not spin around on the pole and the blades smacked the pole, as normally happens with a bent pole Pete. Sometimes it just works |
||||
 Print this page |
