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Forum Index : Windmills : NEW morphing HAWT / VAWT!
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KarlJ Guru  Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
Came to Melbourne for my sisters wedding  ,
Spent some time cleaning up the wedding car (3 Daughters was cheaper to buy our own) 
went up to the farm for a look at my beloved windmill..... Much to my surprise, it was trying to fly UP! 
Took a leaf out of Jimbo's book, just because we could! 
Nature of the failure VERY lucky!! prop going this way instead of via the tower 
Datalogger shows 41.6m/s or just under 150KM/hr winds at some short time before the failure occurred but in the words of Gordon the great "ANY WINDMILL LEFT UNATTENDED WILL FAIL" this is the first maintenance it has needed, bearings still A1, stators show no signs of corrosion, tail needs a repaint, blades are perfect, still in balance too. I also note not many 'mills have survival speeds greater than 40m/s and much to Phill's credit he has offered not only to fix it, but fix it better! What a beast!, destined to fly again soon. BTW 315KW/hrs on the dial so far in 7 ish months. Luck favours the well prepared |
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| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Karl No good buying a lottery ticket you luck is used up. Bob Foolin Around |
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Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
I think that is the luckiest failure i have ever seen. You could not design it to fail like that if you tried. It really comes back to the many conversations that we all have of underestimating the force of the wind for those 1 or 2 days a year. Mother nature will always win. (she's a bitch like that) Pete. PS:- Your sister is better looking than you  Sometimes it just works |
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fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
Hi Karl , I have to agree with Pete about your sister ! As we have already discussed the fix which will be to extend the yaw bearing shaft through the box section which will srengthen the failure area to the point where it should be good for 80m/s, hopfully that doesn't get tested. I think increasing the off-set adj to allow earler furling will also be a good move. From the pictures it is unbelievable that no other damage was done , I must say though, that the hammering this mill takes in your wind zone and being grossly over powered in the blade dept with the 3.050mt Al blades on a f&p dual, I could only imagine the blades are getting up over 850RPM and the forces it has to deal with in wind of 40M/S ( 130+ KLM ). It would be great if we could see what is happening with this mill with a live piclog set up. In the past weeks down there the wind strength has been cyclonic and must have taken its toll on quite a few mills , I know that the figures that Amack was punching out at approx the same time out of one of the Chinese 500W Conversions that I sell also eneded up in smoke after punching out over 1600W , I will be posting a full story on that soon as the mods that are to be trialed should be ready to be flown again soon . I suppose it comes down to the question , Do you lock down your mills when a extreemly high wind event is approaching and live to fly the next day or keep on engineering to survive the 1 to 2 Days a year or the 1 day in 5years and so on . Its great to see the big figures, but in the long run everything has its limits, and for a few hours punching out record figures being wasted in dump loads that can mean weeks of constant power loss to be able to find out the weak points that can sometimes be benificial to others only if they are able to build to the specifications of that particular mill. PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
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| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Karl and Phill I also agree that your sister looks better than you Karl, but you should be glad she tied the knot when she did to give you the inspection of the damage. Looking at the photo you posted I must agree with Phills comments on the oversize blade being a contributing factor, as the gyroscopic forces of that size blade acting through the critical point where it failed are enormous, the furling of the blades creates these stresses, and making it stronger there will transfer the stresses to the next weaker point of construction. What it needs is a yaw damper to slow the furling so it isn't wip furling on gusts as that is what is causing the damage. Karl, you will be aware of the damper used on helicopter blades for this purpose, without it the rotor head will destroy its self in short time. All the best Bob Foolin Around |
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| isaiah Guru Joined: 25/12/2009 Location: United StatesPosts: 303 |
Karl Dont feel bad my mini mill crashed today also.'  '
No real damage but had to bring it down and put new screws in the hub and put the hub back on.. When you have that box fixed you may want to have it stress relieved, or normalized. It looks like the crack followed the weld around for a ways then probably the weight took over and started to peal the metal out. Yes your Sister looks better than you but I like the Car What is it?'  '
Do you and the car hire out for events like this? It might be a good side line job.'  'URL=http://www.motherearthnews.com/Renewable-Energy/1973-11- 01/The-Plowboy-Interview.aspx>The Plowboy Interview[/URL> |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
Pic of my sister is with new husband not me but I guess you guys have seen the pics of me too. Car is a MKVII Jaguar, dad rescued it from a barn in a very poor state of repair with his best mate (RIP), hence he'll never sell it. Each time he drags it out a collection of lack of use failures occur, this time "only" a new battery and front brakes siezed (back in the old days sealing of the brake reservoir was poor -result water ends up in the fluid which stuffs everything over time) I dont think a damper on the furling would make a difference, the furling is SMOOTH as silk but yes she's really hooting when it furls off, to the point where even furled the power being produced barely drops off. The real solution is to start sneaking away coin from the missus and go the AXFX, thats still the goal, will be able to extract 4-5times as much power hence keeping the numbers in better control. Phillm and I will talk how many golden coins sooner or later and i'll give it to the old man for his '70th birthday.... I guess more important again to get the furling spot on to avoid the burnt stator that happens with all Axial flux mills when they are pushed beyond limits -unlike the f&P which survives anything. -even abuse! Luck favours the well prepared |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Sorry Karl was there a husband in the photo? i must have missed that
Nice car though. Pete. Sometimes it just works |
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| neil0mac Senior Member  Joined: 26/12/2009 Location: AustraliaPosts: 210 |
Karl, Examine the point where the crack starts with a magnifying glass (if necessary). You may be able to see different grain sizes (increasing in coarseness) radiating out - and possibly slightly different (shades of) colours in some sort of 'concentric circle' pattern. From the shape of the tear, it is doubtlessly due to re-crystallisation in the weld boundary. |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
Its an atypical weld failure, ie weld didnt fail, the surrounding material did. Obviously to tear 5mm thick box section required some very serious loads. All part of the fun and to say I'm happy that Phillm is taking care of it s an understatement, the fact he stands behind the mills is very comforting. My initial thoughts were to beef it up and weld it back together, but Phillm came up with a far better idea that will strengthen it up no end. Luck favours the well prepared |
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| isaiah Guru Joined: 25/12/2009 Location: United StatesPosts: 303 |
Karl Im retired from a machine and fab shop that builds from scratch some of those large Caterpillar truck and end loader frames. These start out a a sheet of steel and some forgings and parts are cut to print and welded then the are sent out to heat treat and stress releaved then brought back and machined. When you machine a weld or weld joint you see that the area around the weld looks different than the area not welded and the weld area and weld is harder. Without stress relief or normalizing this is where the trouble begins. So the stress and vibration of the wind turbine if possible I would have it normalized or stress releaved. In welding the weld area gets very hot and expands the as it cools it shrinks this where the trouble is. Depending on the function of the weld joint it may not need to be stress releved or normalized.your weleder man can do this to some degree with a torch after welding is complete. In handling the sheets of steel we see imperfections in all steel even the certified steel plates you can get a bad one and depends on what country the steel comes from as to the real quality. URL=http://www.motherearthnews.com/Renewable-Energy/1973-11- 01/The-Plowboy-Interview.aspx>The Plowboy Interview[/URL> |
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| dwyer Guru Joined: 19/09/2005 Location: AustraliaPosts: 574 |
Hi Karl i had a good look at box section as is nothing wrong with Phill's welding but bearing shaft should made longer so longer bearing shaft should weld at the bottom of box tube and the top and that where the strenght is however remmeber is only one off no-one is perfect and we learn the mistake sometime however what puzzle me is why you hire big crane cost you a forture instead having a hand winch?
dwyer |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
The crane we got as we couldnt actually see what had failed or what was holding on to the mill head. Hence it was simply a preservation exercise,my mill needs no winch, it is balanced and pivots over for maintenance. My fear was that if i pivoted it over and the mill broke off and hit the ground OR ME... we would have been up sh!t creek. This was the safest method to get it down without breaking me or the mill. Had I known the failure was as we see it here -no problem. If something different was the case, ie just being held by the wiring which had chaffed away over the previous couple of days might have been a very different picture. It wasnt that long ago the forum mourned the death of a father and son whose windmill touched powerlines while they were moving it across the farm, having a wife in OHS and taking safety as seriously as I do this was the best choice to make. Luck favours the well prepared |
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| dwyer Guru Joined: 19/09/2005 Location: AustraliaPosts: 574 |
Hi Karl Fair enough Karl 
Dwyer the bushman |
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| JimBo911 Senior Member Joined: 26/03/2009 Location: United StatesPosts: 262 |
Karl Sorry to see your mill in that shape. I know how it feels. Gotta love those cranes. Tell you what, when mother nature and her wind says LOOK OUT she can really do some serious damage. I would have to agree with Phill at times shutting it down Completely may be the best way to keep our machines in one piece. Even the best built mill can and end up in pieces. Hang in there. Jim |
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shawn Senior Member Joined: 30/03/2010 Location: New ZealandPosts: 210 |
Hi just thinking out loud and im always going over old ground, but when you said you wanted ax flux, (as we all now do)got me thinking you have a great mill there why not put neos in the hub and maybe even replace the wire with thicker grade I think this would make a huge diference in output and apart from your time would not cost much!! Could all be done while mill still working and when ready bring her down swap stators and hubs. This to build from scratch might as well build ax flux but your caps etc all set up now. No daughters to look after so could do in your spare time
Has this been done with a dual ? Would be sweet to beat amacks 1600 watts and live |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
I run the 100S and an 80S as per Phills recommendation two 100S are worth another 100W in the top end. As for the Neo's it would be nice BUT i do like seeing it spin when the anemometer is stopped and with Neo's there is no way that would happen. Also the Phillm Mill I have is ready to rock'n'roll with AXFX. Again to Phills credit its just like an adjustment to swap AXFX for F&P. blade hub has adapter plate that swaps over to suit the AXFX and the AXFX stator bolts on to the mast bearing (the bit we broke). This was one of Phills masterpieces start cheap with F&P at around $1200, spend the $2K or so later on the upgrade. Luck favours the well prepared |
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| shawn Senior Member Joined: 30/03/2010 Location: New ZealandPosts: 210 |
Ok I guess your set on axfx and yes Phill has done his homework great mills!! I do like my dual mill and it seems with the new chinese mills around and axfx that its the bottom of the list now 
and I am curious what power I would get if I put neos in it, I have a spool of 1.6 wire here and was wondering if I put it in how much this would help also 
sory have wanderd off thread A bit. |
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Big Al Newbie  Joined: 06/10/2010 Location: United KingdomPosts: 38 |
As a newbie my only useful input is that your sister definitely is better looking than u or her husband and probably could have had her pick of a herd of crane owners-but thats sisters I guess (sigh ) - and you are a lucky B---D. The guys at Mawson Antartic base must wonder why u bother with a windmill at such low wind speeds.  Big Al Every Day is a school day (even at 67) |
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| KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178 |
Its funny you should say that re the Mawson base those mills spend lots of time shut down due high wind..... Luck favours the well prepared |
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