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Forum Index : Windmills : Another dead mill

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shawn

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Joined: 30/03/2010
Location: New Zealand
Posts: 210
Posted: 06:00pm 14 Jun 2012
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It seems my pile of dead bits still grows trouble is its the shortest daylight time of year and my PV is slow not to mention 1 meter of snow on top of them
Anyway here is a picture of my failed mill



Here is the worst coil





Here is the lead to the kill switch





Oztules blades just have to much grunt! Ive seen spikes of over 100 amps easy and they didn't cause this!
The wind was gusting around 140 km
So the rebuild continues
 
Madness

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Joined: 08/10/2011
Location: Australia
Posts: 2498
Posted: 06:58pm 14 Jun 2012
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Ouch
There are only 10 types of people in the world: those who understand binary, and those who don't.
 
mac46

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Joined: 07/02/2008
Location: United States
Posts: 412
Posted: 05:15pm 15 Jun 2012
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Shawn,
Thats a real messed up mill, sorry to see the failure. There is some work being done with variable pitch blades, auto breaking, and furling...not for 140km winds though...not sure anything would be standing and still working after that.

Mac46
I'm just a farmer
 
Georgen
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Joined: 13/09/2011
Location: Australia
Posts: 462
Posted: 05:21pm 15 Jun 2012
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Any chance to get rid of some current once it reaches certain level?
(Say anything above 50A gets wasted – sorry, but have not enough knowledge how)

Seen also somewhere that with wind reaching above certain speed blades get disengaged and stop producing any power.

(Probably silly idea, but maybe strong magnets could be used to detach blades at certain wind pressure
Say at 60 or 80 km an hour, magnet would let blades go away by few milimetres and turbine would stop.
When wind speed drops, weak spring could send blade back far enough for magnets to snap back again)Edited by Georgen 2012-06-17
George
 
Gizmo

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Joined: 05/06/2004
Location: Australia
Posts: 5078
Posted: 02:39pm 16 Jun 2012
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  Georgen said   Any chance to get rid of some current once it reaches certain level?
(Say anything above 50A gets wasted – sorry, but have not enough knowledge how)

Seen also somewhere that with wind reaching above certain speed blades get disengaged and stop producing any power.

(Probably silly idea, but maybe strong magnets could be used to detach blades at certain wind pressure
Say at 60 or 80 km an hour, magnet would let blades go away by few milimetres and turbine would stop.
When wind speed drops, weak spring could send blade back far enough for magnets to snap back again)


Furling the tail is the simplest and most reliable way to control a wind turbine in strong winds, with only one moving part, but it can take a bit to get it working right.

Not much will survive 140kmh winds though.

Sorry to see the burnt stator shawn.

Glenn
The best time to plant a tree was twenty years ago, the second best time is right now.
JAQ
 
MacGyver

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Joined: 12/05/2009
Location: United States
Posts: 1329
Posted: 05:58pm 16 Jun 2012
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Ouch!

Always sad to see something go awry. This is just one of the reasons I'm back to pumping air with my windmills. Besides not being the best machinist (far from it), pumping air into a receiver has only one major problem, that being condensation. A tickler valve at the bottom of the receiver tank bleeds that away and all that's left for me is a tank of potential energy that I can let pass through a GROUND LEVEL air engine coupled to a generator.

If Mother Nture decides to throw a tizzy fit, closing one valve at GROUND LEVEL makes the pump work against a dead head and everything comes to a screeching halt.

I like simple.

After I've made my move to Texas, I'll throw up several air pumpers and do the full-salon-treatment, show-'n-tell presentation here on the 4m. That should be about September if things continue on schedule.


. . . . . Mac


Nothing difficult is ever easy!
Perhaps better stated in the words of Morgan Freeman,
"Where there is no struggle, there is no progress!"
Copeville, Texas
 
Madness

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Joined: 08/10/2011
Location: Australia
Posts: 2498
Posted: 06:37pm 16 Jun 2012
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Has anyone tried connecting a brake to the tail so when it furls past a set point it will apply the brake. Also a latch could be added to the furl so once it goes far enough the tails is held in the furled position until manually released.
There are only 10 types of people in the world: those who understand binary, and those who don't.
 
shawn

Senior Member

Joined: 30/03/2010
Location: New Zealand
Posts: 210
Posted: 10:37pm 16 Jun 2012
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  Madness said   Has anyone tried connecting a brake to the tail so when it furls past a set point it will apply the brake. Also a latch could be added to the furl so once it goes far enough the tails is held in the furled position until manually released.

Sounds good in theroy but in reality the tail in severe wind slams the tail side to side it gets a life of its own I think more detuning is the best I can do I might be able to stuff more copper in there to
 
fillm

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Joined: 10/02/2007
Location: Australia
Posts: 730
Posted: 07:32am 17 Jun 2012
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Hi Shawn,

By the looks of the stator it appears that one phase has lost loading somewhere this could have caused the other 2 phases to be loaded excessivly but with 140k up its clakker 3 cricket bats would do the same, I take it that when you have said detuning means 4m blades are a bit on the big side for the winds you get there and knocking them down a bit would be a good starting point for the next build, if so that would be a good move,

As I have been logging and watching how quickly my AXFX stator heats up when the load comes on, it's not surprising when you can see this and makes you realize how they can very easily burn out from being over driven . Once over about 500W things start heating up fairly quickly and if you are thinking about more copper I would be increasing the wire dia and keeping the coil count the same if your cutt-in is good and go for better current carrying, it looks like you have a heap of room to do it.

I would also highly recomend fitting a manual furl to your set up for high winds , once the tail is locked into the full furl position the power is taken away from the blades, it's then fairly safe to have the stator shorted or leave it run to ride out the high wind event.

Sometimes the simplest solution that has been around for donkeys years on the pumpers works out to be the best rather than trying to re-invent the wheel.

The set up I put on the little 500w Kit worked well and even in strong wind with it fully furled it would still put out good power without the risk of burn out or excessive tower loading. The best thing was by adding a weight it would reduce the furl point and then lock the tail into full furl after a couple of good gusts.

Might be worth havein a think about with your wind conditions for peace of mind.Edited by fillm 2012-06-18
PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits
 
shawn

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Joined: 30/03/2010
Location: New Zealand
Posts: 210
Posted: 12:25am 18 Jun 2012
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Had the afternoon off work, so I dragged my old coil winder out and threw 3 inhand of 1.6 wire in it and wound it up same turns and it is a very tight fit! no chance of putting in more than this! the last stattor only had 2 inhand so a big inprovement
thought I might try anouther coil shape not sure which is best but i will find out soon enough?
Im not going to cut down my blade size! I may furl it sooner not sure yet, and maby the old wind pumper system of locking it into furl might be a go i will think on it a while thanks for the idears.




 
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