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Renewable Energy Questions/Discussion => Wind and Hydro => Topic started by: TurboMiles on November 30, 2016, 09:06:56 am

Title: Blades stalling
Post by: TurboMiles on November 30, 2016, 09:06:56 am
Can someone recommend a blade set and hub that I can purchase for my 1000 watt max turbine.
My currently blades are a 5 blade set from mw&s called g5, they are stalling in 15+mph wind. Or would deleting 2 blades be a better option?
Title: Re: Blades stalling
Post by: niall on November 30, 2016, 02:47:53 pm
Hi Turbomiles

i think i know those blades , its hard to get much out of them  , something like the ametek tape motors might match better . the swept area isnt very big.

a picture of the alternator and tail would help  (lots of variables)   but if it can put out 1k at a safe rpm consistantly without overheating   i,m guessing youd be looking at a standard 3m ( minimum ) diameter prop , 3 blades .....its will depend on the characteristics of your alt and your furling tail set up

if you dont mind nipping away at wood its not too hard to carve a set ...nothing fancy and will work just fine

mounting them onto your alternator could be tricky as wooden blades will be a lot heavier ( more stress/bearing load ) than the mws plastic ones .

taking off 2 i dont think will help ....it sounds like you need a bigger swept area to overcome the stall  .....ish   

i think if you change one aspect of the mill........................you almost denfinetly have to change a few more

there was one commercial mill ( a whisper maybe ) that used blade extenders at the hub to increase swept area a bit , the extenders were left out on its smaller cousin ( same blades ) .....an option but i,m not sure about that though ...... 

good luck with it  :)


   
Title: Re: Blades stalling
Post by: TurboMiles on November 30, 2016, 09:34:28 pm
Thanks for your help!
It's an HYE 1000L, factory blades snapped off, MW&S G5 blades replaced them.  It's always had a tracking problem so I modified the tail and tail boom.  It tracks so good now but doesn't make power above 14/15 mph.
Title: Re: Blades stalling
Post by: TurboMiles on December 01, 2016, 10:31:27 am
http://m.ebay.com/itm/311659534246?_mwBanner=1

Is this worth it?
Title: Re: Blades stalling
Post by: niall on December 01, 2016, 03:23:48 pm
 :)

ok i see the pics now

those mws blades are different to the ones i had ......mine were the smaller " game of thrones  " variety , those look much better

so you have roughly a 2m diameter prop . sticking to the stall issue you mighnt have to go much bigger to improve the situation a bit . a 3 blade 2.2m maybe ...

i,m not sure i,d like to push more than 500w out of the alt , theres plenty of posts on the net of burned out coils on alts slightly on the edge . i,m not positive about that but you dont want to push for the high figures ...more consistant lower power levels would be easier on the alt and let it furl out early

the ebay blades ...a 2.6 m prop then , now seeing the alt i think their to big and if there good quality and run as fast as they should they might burn out the alt. plus......... there fibre glass and might ( probabely will ) be pretty heavy , possiblely 3 times heavier that a basic carved cedar wood prop of the same size , thats going to be hard on the linear bearings in the alt ...not good......and your going to have to customize the hub mount to suit the alt .....

your really in ideal terrority for carving a 2.2m 3 blade prop from something like cedar or any reasonably clear wood , if it doesent work out its really only cost you your time and its nice to see your own work up there.....

from the very little experiance i have and reading others posts about matching the prop to the load its a very tricky business getting it right first time  ( i never could ) especially of ebay .....i bought 3 sets online and none of them worked out ...almost.......but not ....its hard to tell with the ebay postings what quality you actually get.

i,m still wondering about some short 6mm plate extensions for the prop blades at the hub ...its not ideal but a cheap experiment , hacksaw and drill terrority .....if it doesent work thats ok   

when the prop goes in to stall what power is the alt roughly putting out Turbomiles ? .....your mast looks pretty high

sorry not really much help   ???

ps....if you are tempted to make a wood prop heres a link to a nice 2.3m design http://www.scoraigwind.com/selfblade/index.htm
its a powerfull prop so furling would need to be adjusted
 
Title: Re: Blades stalling
Post by: TurboMiles on December 01, 2016, 07:47:54 pm
This is the history, factory hye1000l on a 55' tower.  Basic 80 amp eBay rectifier with 2 eBay1000w 22-60v grid tie inverter.  When the turbine would stay in the wind I could see 1200-1300 watts max.  Typical 200-400w in 13-18mph wind, it worked great.  Then a storm took the blades off.  These G5 blades are 37" long, it's almost 80" swept area and the stock blades had a swept area of 77", same hub.  These G5 blades are consistent in wind from 6-9mph.  6 is worth 5 watts, 7 10 watts, 8 20watts, 9 40 watts, but when the wind hits 10 it goes to 50 maybe, 11 maybe 50, a lot of times I see the power go down.  It requires about 18mph to achieve 100 watts.  I had a slip ring problem do I deleted it, connected directly now.  Had a rectifier problem, homemade a substantial rectifier.  The only thing left is the blades.  If I disconnect the turbine and let the wind spin it up and connect it again, I see huge numbers, then it just falls off over the next few seconds. So where the power falls off is at 10 mph and it's making about 50 watts.  I see my blades making power on YouTube, so I don't understand why they don't make power on my turbine. 
The turbine does not have a furling tail, it is fixed.
Title: Re: Blades stalling
Post by: TurboMiles on December 02, 2016, 12:57:30 pm
I have found that removing 1 of the 3 phases from the rectifier makes more power then all three connected.  Does that mean anything?
Title: Re: Blades stalling
Post by: oztules on December 02, 2016, 01:54:55 pm
Yes... it means that you have a poor matching of the load to your blades.... ie the tsr of the blades is too high for the stiffness of your alternator.

You can either

1. use a higher voltage battery bank, and that will change the behavior,

2. carve different blades.

3. leave two phases off so that it can run at a faster speed as you have found,

4. Put in three transformers to step down the voltage to the batteries. ( or a three phase transformer )

5. Use a buck converter to step the voltage down.

6. Place some resistance in the DC line to allow the blades to run up faster. You lose power in the resistor, but the blades will run faster and should compensate with more power over all.

7. Throw it away and buy more solar :)


..............oztules
Title: Re: Blades stalling
Post by: TurboMiles on December 02, 2016, 01:58:48 pm
Thanks for all the options
Title: Re: Blades stalling
Post by: niall on December 07, 2016, 06:08:03 pm
55 foot tower ...thats impressive ..a long way up,,,
Title: Re: Blades stalling
Post by: TurboMiles on December 09, 2016, 03:50:58 pm
And its still not is the best wind,  too many trees
Title: Re: Blades stalling
Post by: TurboMiles on December 09, 2016, 03:54:39 pm
And it has begun
Title: Re: Blades stalling
Post by: niall on December 09, 2016, 04:22:28 pm
 :)

it seems it has ....welcome to the dark side turbomiles  ...whats the diameter ?

the blades look good and i,m sure will go like a scalded cat .....you may well need some kind of furling mechanism now , especially at 55 feet and when the weather goes to pot .....everything will go variable and the gremlins will try to come out and find the weak spot

good luck with the carving........
Title: Re: Blades stalling
Post by: TurboMiles on December 09, 2016, 05:03:40 pm
Just under 10', each blade is 4' 11".  Planning on building a jig and rough cut with a chainsaw.
I don't plan on furling this one but the axial that I plan on building will furl.  Will try to control it with 2000 watts of load and 3000 watts of dump. Maybe it will kill my coils, we shall see.
Title: Re: Blades stalling
Post by: TurboMiles on December 09, 2016, 11:41:41 pm
How am I doing?
Title: Re: Blades stalling
Post by: oztules on December 10, 2016, 02:13:15 pm
Carving looks good so far....... very good.
Was that roughed with the chainsaw?

I am a bit twitchy around the bung hole about 10' with no furling. A big wind through those blades will be 30kw and more to try to look after. If your alternator is very stiff, you will possibly control it.... if not stiff enough, it will leave the coils smashed and tangled.

50mph winds here are common, and if shorted, my 4m unit was no problem, but if it was running without furling, it would end up in New Zealand, no hope of keeping it under control if I didn't short it out in big winds. Furling gives a good degree of safety, but it is not infallable. The physics look good, but in the real world, the mill can do odd things in wild winds, and can track without a tail for short times.... enough to cause problems..... but it is a far cry from no furling.

You really need a plan B... so try furling ..........of any kind... better than no kind. Big winds are scary when they get out of hand, and a well carved set of blades can rally take advantage of them....... the toy plastic ones are just not the same.



................oztules
Title: Re: Blades stalling
Post by: bj on December 11, 2016, 05:15:06 am
   Your carving looks great.
   Have to agree with Oztules about furling.  Been there  with a crazy wind, and there wasn't much left.
Title: Re: Blades stalling
Post by: TurboMiles on December 11, 2016, 07:38:41 am
Roughed cut with a chain saw, but with the help of a jig I made, then 10 minutes with a belt sander,  Picture!
No Furling is a bad idea.  Didn't take much looking to find good information.  I'll fab up something to make the existing tail pivot and rise.
I would like nothing more then to finish these blades but work schedule doesn't allow right now.
Title: Re: Blades stalling
Post by: niall on December 13, 2016, 03:11:17 pm
the blades look spot on ......heres a link to one furling method , used on Piggott mills i think and works well ......theres a few others

http://www.thebackshed.com/windmill/Docs/Furling.asp

it doesent have to be exact , but closer is gooder than nothing 

if the 2 tower pivot angles and tail/boom weight are in harmony the tail will lift and drift in a clean vertical line ...or...if the welding is a bit ( i,m going to have a go at this right now with the welder ) it may rotate a bit as it lifts....its still furling though  ???

the tail may go on some kind of a sponsered walk of kinds in high winds....but a sponsered walk is often........... just fine

as was mentioned furling is an odd thing   .....theres a vid of a Proven 3k downwind machine running upwind in a storm when it had no earthly business doing so......

hopefully you can update more later  :)   
Title: Re: Blades stalling
Post by: TurboMiles on December 13, 2016, 03:36:50 pm
Probably not the best pictures, but not the best photographer.
I understand furling, but the problem I have is the turbine is centered over the tower.  All furling systems I've seen are offset.  So I thought about disconnecting the generator from the pivot housing and making a bracket to offset it. 
Or I can leave it as it is, make smaller blades for out and save the big blades for an axial.
Title: Re: Blades stalling
Post by: niall on December 13, 2016, 04:07:04 pm
modify and go for a offset ........furling will work better that way
Title: Re: Blades stalling
Post by: bj on December 13, 2016, 06:43:58 pm
Niall is quite correct.   You need the offset.  The tail fights the offset to keep it into the wind, until the offset over
powers, and lifts the tail.  Once lifted, the tail no longer has the leverage to hold it into the wind, and things tame
down until the wind subsides enough for the tail to fall, and it starts all over again.  There are angles, lengths etc
in the Dan's book, and they work, but I think I lent mine out, and it is lost. (or permanently adopted)
Title: Re: Blades stalling
Post by: TurboMiles on December 13, 2016, 07:01:22 pm
I own 2 Hugh Piggot books.  Everything I need to design a furling system is in the books.  It's actually a simple design and I believe I can make a good rig out of my existing genny.
Title: Re: Blades stalling
Post by: TurboMiles on December 18, 2016, 10:20:18 am
Does it matter if the blades have a curve to them?  I finished the blades and one have about a 3" bow into the wind. Would it be ok to use?
Title: Re: Blades stalling
Post by: niall on December 18, 2016, 07:44:15 pm
i,d say it,d be ok ......i wouldnt drop a blade just because it fished a bit from the other side of the river 

3" inchs is a fair bit in tracking .....it might tend to rock the mast a little bit  ....not sure about that though

my 3.7m had one blade tip off by about 1.5 " .....it never seemed that bothered about it at all  ( the least of its worries )......i wouldnt let it hold you back ,

balance them as well as possible and let them run ....wood will change its shape and balance with moisture anyway

once the blades are out in the open they will all change a bit ........but wood is pretty adaptable at surviving in the wind

i,d worry more about joining the blades at the hub and to the alt ......2 nice disks of strong ply front and back and plenty of stainless ( ideally ) screws 

( you might be able to correct the bend a bit by off setting that blade at the hub ....sand off a little and shim it a bit .....that might take the tip tracking back to about an inch )
Title: Re: Blades stalling
Post by: TurboMiles on December 19, 2016, 04:48:08 pm
What I have so far.
Title: Re: Blades stalling
Post by: niall on December 19, 2016, 06:53:05 pm
very nice work ......you wont get a set of those of ebay ...ideal for Hughs 2.4m design ...methinks
its good to see someone carving blades......



 
Title: Re: Blades stalling
Post by: TurboMiles on December 19, 2016, 07:04:49 pm
2.4?  These blades are 5' lol should I cut them down to 2.4m or leave it at 3m.  I'm building a furling system
Thanks for the help niall.
Title: Re: Blades stalling
Post by: bj on December 20, 2016, 05:36:48 am
  Turned out very nice.   Just opinion, but I wouldn't cut them down just yet.  You can always
do it later if you need to.
Title: Re: Blades stalling
Post by: TurboMiles on December 20, 2016, 06:35:04 am
I'm sure it's important that all blades be very close to the same dimensions, but how important is it?  They are all close, but is the airfoil identical on all, no.  Does it matter much if they balance out? 
Would there be any downside to having blades to large for the generator if it furls? 
The factory blades would produce 100 watts at ~11mph, 200 at ~15mph, could you tell me what I could expect to see with the new blades?
Title: Re: Blades stalling
Post by: bj on December 21, 2016, 05:16:11 am
   Not the expert here, but------
   Airfoil not identical?  Not so bad.  They will all induce torque to the same shaft.
   Weight not identical?  Not so good.  It will shake things and depending  on how much
difference there is, it can cause damage.
   Originally you didn't have enough blade so it should be better now.  How much is the
result of many factors, so I won't guess, but it should be better.
   It will be interesting to see the results.
Title: Re: Blades stalling
Post by: niall on December 21, 2016, 05:19:05 pm
you,l  probably have to balance them on the alt which is fine ( ideal really ).....on an axial alt its completly free spinning , no resistance ...easy to add lead in the right place at the hub

the chineese alt might cog a bit , not really an issue , but you can fine tune balance by adding a small 1 ounce weight ( or something small ish ) at the blade tip ....

place the little weight sitting on one horizontal tip .......( or a known distance in ) ......the blade " may " drop with the added weight

take it off and rotate to the next blade and repeat ......it too " may " drop at the same rate and amount

rotate to the last blade .....with the little weight sitting on the blade it may not drop ..........thats your light blade ......add lead at the root  .....and on it goes using lighter weights each time

fine balancing is ok ....but you,ll loose the will to live taking it too far ......the wood will absorb/dry out water over time and the balance will change anyway....but like Bj said ....balance is worth getting as good as possible.....it,ll start up quicker ,and just generally run smooth 
     
Title: Re: Blades stalling
Post by: TurboMiles on December 21, 2016, 09:52:33 pm
Thanks for the help.
The wood shouldn't change much as it will be sealed.
Title: Re: Blades stalling
Post by: Wolvenar on December 25, 2016, 12:00:54 am
Sealed or not, it will change.
Water finds a way... always.
Then in a different season, or dry, wet, hot, cold period the sun and or temps will change it up yet again.
Title: Re: Blades stalling
Post by: TurboMiles on December 25, 2016, 12:20:15 am
Your right it will gain or loose 100lbs, my bad for saying it shouldn't change much
Title: Re: Blades stalling
Post by: niall on December 29, 2016, 05:37:40 pm
i,d agree with Wolv ...moisture will try very hard to get in turbomiles.....and with sealed blades it might not be able to get out ...at least as it should ...ish... :(   it could be a pain in the ass 

not worth a hill of beans here .. where i live it tends to rain a lot ......an awfull lot .....like a depressing amount of a lot ......so the blades here like a breathable wood paint on them , they kind of adapt to extremes....they get a bit wet ....they dry out ....the balance changes....and goes back

one extra option for sealing (and you have your own thoughts on this already ) is linseed oil

i never ran these blades ( i should have ) but linseed oil seems pretty interesting  .....the blades are basically soaked in the stuff....it eventually dries out and hardens ( crystallizes or something  )

this was the breathable paint version in sugarpine ....

sorry pics are upside down.... :)    linseed oiled version is bottom

your blades look ready to fly .....whats not to loose .... :)
Title: Re: Blades stalling
Post by: TurboMiles on December 29, 2016, 07:05:06 pm
The blades have been indoors for the past week trying to get any moisture out.  Maybe this is wrong but it's what I've done.  I have bought boiled linseed oil to put on the blades as recommended in Hugh Piggots book.  Looking forward to getting the time to apply it and mounting on the hub.  I know I need to build a furling system for this but first I'm putting the blades on with out furling to see how well they work. 
Title: Re: Blades stalling
Post by: TurboMiles on December 29, 2016, 07:12:07 pm
NIALL, your blades look amazing.
Title: Re: Blades stalling
Post by: niall on December 30, 2016, 03:29:46 pm
thanks ...but its Oztules chainsaw method and Hughs free online plans that make it easier for knuckle dragers like me

your running a big mast ...that,l test things pretty hard and fast .....( you need a herd number/farm to go to 20m here without planning permission  ) 

and again good luck with it  :).......

when you do test the blades do it on a calm day  :).....shorting the alt should/might stop it in light winds .....a lot of variables



 
Title: Re: Blades stalling
Post by: TurboMiles on December 30, 2016, 04:21:31 pm
We have a few days of light north wind 10mph, hope to have it up for that.
I have applied 1 coast of linseed oil to all the blades and the triangles, plan to put a few more before I screw it all together.  Maybe it will be installed by the end of the day Monday.

We're you saying a big mast will test it hard and fast?
Title: Re: Blades stalling
Post by: niall on December 30, 2016, 06:01:26 pm
the alt .....yes

axials can stop a mill in a second ......radials.....i,m not so sure
Title: Re: Blades stalling
Post by: TurboMiles on December 30, 2016, 06:41:19 pm
I can stop my current setup in a 35mph wind, not saying I will be able to with the 10' setup
Title: Re: Blades stalling
Post by: bj on December 30, 2016, 08:54:55 pm
Sounds like the winds you are expecting are just right for a test.   Best of luck
Title: Re: Blades stalling
Post by: TurboMiles on December 30, 2016, 09:32:58 pm
I really want to build an axial. I need to tailor it to work with my grid tie inverters and I'm not exactly sure how to do that.  The inverters turn on at 22v and divert to dump loads at 60v.  I have 2 1000w inverters in parallel.  Everything I find in my book is about charging batteries.
Title: Re: Blades stalling
Post by: TurboMiles on January 02, 2017, 05:41:58 pm
Wind is lite and she is flying.  Start up is ridiculous, 2mph, makes 12v in 4mph. I didn't do a very good job balancing.  It wobbles my tower. 
Title: Re: Blades stalling
Post by: niall on January 03, 2017, 02:12:38 pm
looks good ... :)

had you any trouble adapting it to the alt mounting shaft ?

the balance musnt be to bad if it starts up that easy....

when the wind drops does the prop tend to fall back to one position ?

maybe its that blade thats tracking a bit off , that will try to wobble the alt and at your height i " guess " it amplifies any mis balance/tracking ......i only helped working on one mast that went to 20m here and its not a quick job taking it down to reset balance......so cant advise much

 [attachimg=1]

its all knowns or unknowns from here out  :)
Title: Re: Blades stalling
Post by: TurboMiles on January 03, 2017, 03:46:10 pm
It does start in lite wind but I'm pretty sure it's not balance properly.  At higher rpm the wobble goes away.  Tonight we have 15-20mph wind and I'm curious to let it fly in that for a bit, but scared at the same time.  Scared that I may not be able to stop if I turn off the brake switch.  I'm at work for the next 3 hours, the wind is blowing at the house but she is locked down. 
Just yesterday we had very lite wind and I can already see the potential of these blades.
There was no problem bolting to the alt, 3 blades with the triangle on the face, screwed together and all that bolted through to a steal 1/4" disc.  Went together nicely. 
Title: Re: Blades stalling
Post by: niall on January 03, 2017, 04:27:23 pm
fear is good ....not natural but good .....time to calm those blades .....
Title: Re: Blades stalling
Post by: TurboMiles on January 03, 2017, 08:06:20 pm
Ok, fear is gone, all is well.  Took it off the brake, had my 500w  11-30v inverter and 2 1000w 22-60v inverters in parallel.  It makes great power compared to what I'm used to. The 11-30v inverter controls the turbine really well, but when the wind gusts from 12mph to 17 the small inverter can't load it fast enough and the voltage comes up and the big inverters turn on to help control it.  Works great! 
So I was curious, I unplugged the small inverter and let it spin, but it didn't make as much power, didn't record anything, but maybe 50w less in the same wind.  It does spin faster but makes less power, not sure why. 
Another thing, these blades make a lot of noise.  Well it sounds like 1 blade making noise but it sounds like an alien craft landing in my back yard lol.  I don't know how to describe it but I can here it in my house.  The sound gets louder the harder the wind blows but not related to the turbine rotor  speed. 
Title: Re: Blades stalling
Post by: TurboMiles on January 04, 2017, 08:41:57 am
The noise appears to be associated with the amount of load. More load more noise. 
Title: Re: Blades stalling
Post by: hiker1 on January 05, 2017, 12:43:41 pm
Could be that warped blade..catching more air ..makin that noise..when under load the air dosent slide over as easily and builds up a bit..  To balance my blades I mount on a free spinning shaft...then give a spin...then just add weight to the hub on the light side....adding weight to the blade tips..isn't the best idea....tried that once...in a good wind the blade tip broke lose..
Title: Re: Blades stalling
Post by: niall on January 05, 2017, 04:41:52 pm
it could be the alt making the weird noise , i know some of Hughs machines have been grid tied and the hum/noise changed a bit/lot ..... ( louder ? )

with battery based systems ( i think ) things tend to be quieter......

i tried a very basic pwm controller ( no batteries/capacitors  ) on the mill ...kind of one big mosfet ......the modulation of the current made the alt sound like something out of war of the worlds ....a loud modulating groaning sound ....it basically turned the alt into a loudspeaker .......the mosfet blew up pretty quickly after and shorted the mill

wood blades are usually quieter than most as well....strange you hadnt the noise issue before.....maybe your new blades are pushing it harder ...

putting some big capacitors on the rectifier might help .....i,m not sure if thats a good thing for your invertors though ....it may help ...ish.......

i dont use batts on the mill now ...just big capacitors then into a pwm dump .......but the mill will kill them too over time

your watching it close though ......thats a good approach  ???

edit....just checking the caps on the mill rectifer  ....their 2 10000uF 80V electrolytics in parallel .....

your in unkown terrority .....
Title: Re: Blades stalling
Post by: TurboMiles on January 05, 2017, 07:25:27 pm
Dropping the tower down tomorrow morning to investigate.
These blades make about 350-375watts in a 15mph wind, the blades that these replaced made 100ish watts in 15mph.  The original blades that came with the mill made 200watts @ 15mph.  It's pushing it harder. 
I believe there may be an imperfection on the top of the blade, may have to cut them down a bit, they are 2" longer then the drawing specs.  So I may remove these 2", go from 10'4" to 10'.  Then balance again.
 Headed to the store now to get a few materials. The tail is tiny for this big rotor and the boom is to small.  May get stiff to fix that too while it's down.  It will be back up tomorrow afternoon and we have 2 days of great wind.
Title: Re: Blades stalling
Post by: TurboMiles on January 05, 2017, 10:21:58 pm
Got anxious, could this be the source of the whistle?
Title: Re: Blades stalling
Post by: TurboMiles on January 05, 2017, 10:40:43 pm
Is this a decent way of balancing?
Title: Re: Blades stalling
Post by: TurboMiles on January 06, 2017, 09:07:10 am
I cut an inch off each blade and filled the hole in the blade, no change.

Title: Re: Blades stalling
Post by: hiker1 on January 06, 2017, 12:49:59 pm
That's. Loud......dout if it's the knot....are the blade tips sanded smooth..tapered a bit ?...never had a carved blade do that..
Title: Re: Blades stalling
Post by: TurboMiles on January 06, 2017, 12:56:39 pm
I the tips are cut clean off, straight
Title: Re: Blades stalling
Post by: rossw on January 06, 2017, 01:27:51 pm
I the tips are cut clean off, straight

My original (commercial, chinese) turbine blades were like that, and it screamed like a banshee!
(http://house.albury.net.au/05jan2007/000_0114.JPG)

I took to them with an angle-grinder and feathered them
(http://house.albury.net.au/05jan2007/000_0109.JPG)

Then painted them with a hard epoxy paint
(http://house.albury.net.au/06jan2007/000_0127.JPG)

And finally sanded them smooth with fine wet and dry paper. After that, they were whisper quiet.
(I don't have a pic of them when finished, unfortunately).
Title: Re: Blades stalling
Post by: TurboMiles on January 06, 2017, 07:27:50 pm
I tried rounding the tips and still makes just as much noise.
Title: Re: Blades stalling
Post by: TurboMiles on January 06, 2017, 11:26:19 pm
We are having a Damn good long front come through and I can't run the wood blades, neighbors will murder me.  So I reinstalled the G5 blades, they work OK if I remove a phase.  The wind is blowing 15-20, gusts to 25. It was mentioned that the noise could be the alt, no chance it's the alt.  I do hear a groan from the alt, but the high pitch whistle is all the blades.  I need to figure out how to remove the whistle and everything will be great.  I've had the wood blades in a 20mph wind and the inverters I have is able to control it, haven't had them up for higher winds.  The wood blades are so powerful, I want to run them so bad.  I believe I may have carved them wrong, but not sure where I went wrong.  Can I see pictures of your wood blades?
Title: Re: Blades stalling
Post by: niall on January 07, 2017, 01:57:29 pm
if the blades are working that well .....you mustn't be to far off   :)

heres a 1.2m blade ....the wood is cedar with an ash leading edge

its a standard blade with a tsr of 5 ( if i rembember right ) ....
the drop angle at the tip is about 2mm and extends out to whatever the wood thickness allows at the root , the airfoil is standard ( the belt sander variety )

these were done of a blade calculator but there basically close to Hughs 2,4m prop

[attachimg=1].........................[attachimg=2]
[attachimg=3].........................[attachimg=4]

this is the 3.6m mill .....the blades are the same format and are basic hardware store pine laminate ...just bigger , as you can see the mast is short at 10m

the cut in rpm is about 140rpm ....so its a " fairly "  quiet machine , cut in for the 2.4m would be 210 rpm so the 3.6 is kind of a quieter machine ...ish , the neibhours were never to bothered about it and at 10m even if it fell it would stay on my side of the ditch  ( things that go bump in the night )

[attachimg=5]

as its going up the tail falls into its furled position , this drops back as the mast goes vertical

the only time it made a whistling noise ( similar to your vid and what Ross described ) was when i tried adding winglets to the blade tips....i had to knock them off 
Title: Re: Blades stalling
Post by: TurboMiles on January 07, 2017, 04:13:17 pm
The lack of a sharp trailing edge was the source of the whistle, all I get is a whooosh sound now, happy :)
Title: Re: Blades stalling
Post by: TurboMiles on January 07, 2017, 05:20:22 pm
Title: Re: Blades stalling
Post by: rossw on January 07, 2017, 05:31:48 pm
The lack of a sharp trailing edge was the source of the whistle, all I get is a whooosh sound now, happy :)

Errr... that's what I meant to demonstrate with my pics.
Title: Re: Blades stalling
Post by: TurboMiles on January 07, 2017, 05:42:25 pm
The lack of a sharp trailing edge was the source of the whistle, all I get is a whooosh sound now, happy :)

Errr... that's what I meant to demonstrate with my pics.

I'm sorry, I thought you were showing me the tip and how you rounded it off.  My apologies.
Title: Re: Blades stalling
Post by: rossw on January 07, 2017, 05:45:58 pm
I'm sorry, I thought you were showering me the top and how you rounded it off.

Nah, it's all good mate. The original pull-truded blades were cut off hard at the end, and along the trailing edge.
Certainly, I rounded the sharp ends off, but the main difference came from re-shaping the trailing edge to take it back to a nice, fine, smooth edge.
Title: Re: Blades stalling
Post by: TurboMiles on January 07, 2017, 06:46:26 pm
How long are the Chinese blades and what kind of alt do you have them on?  Do they make good power for you?
Title: Re: Blades stalling
Post by: rossw on January 07, 2017, 07:05:16 pm
How long are the Chinese blades and what kind of alt do you have them on?  Do they make good power for you?

I've had, and got, a variety.
The original (junk) ones were just under 10' diameter, junky hard fibreglass with hard edges and not much profile. I ground them, painted them, balanced them, and got reasonable performance from them but lousy start-up.
(http://house.albury.net.au/23feb2006/MVC-222X.JPG)

After they were destroyed by a tree going through it during a storm:
(http://house.albury.net.au/22jan2009/100_3176.JPG)
(http://house.albury.net.au/22jan2009/100_3181.JPG)

I rebuilt the head, and bought some new blades and hub (which needed some machining to fit the old generator head)
(http://house.albury.net.au/18jun2009/100_3448.JPG)
(http://house.albury.net.au/24oct2009/100_3918.JPG)

These started up much better, were far quieter and produced more watt-hours per typical day, but were down a little in top-end power for some reason I'm at a loss to explain. Perhaps in all the rebuilding, the alternator lost some output.
This old mill makes around 1KW peak in strong winds.

I have another one I still have not put up yet. It's 2.5KW and I have little doubt it'd make that easily in a decent wind.
Its prop is just over 14' diameter. I have a picture from when I was balancing it, but it's pretty awkward to manage inside and impossible to do outside except when it's dead calm (almost never!)
(http://house.albury.net.au/12dec2009/100_3998.JPG)

I've got another 7.5KW of PV to put up, so I honestly don't see this new mill ever flying.
Title: Re: Blades stalling
Post by: TurboMiles on January 07, 2017, 08:07:50 pm
Impressive!  Does the 14' prop use an s809 airfoil?  Would these be going on an axial?
Title: Re: Blades stalling
Post by: rossw on January 07, 2017, 08:28:58 pm
Does the 14' prop use an s809 airfoil?  Would these be going on an axial?

I'm not sure. Bought it about 8 years ago and can't remember the details.
The machine that came with it is radial, not axial. Looks to be a modified but hefty 3 phase induction motor
(http://house.albury.net.au/12dec2009/100_3989.JPG)

(http://house.albury.net.au/12dec2009/100_3993.JPG)

Weighs about 60kg (130 lbs) by itself if I recall correctly...
Title: Re: Blades stalling
Post by: TurboMiles on January 07, 2017, 08:35:22 pm
That looks serious.  You should put it up lol. It would be a monster.  The sun doesn't shine 24/7.
Title: Re: Blades stalling
Post by: rossw on January 07, 2017, 08:41:59 pm
That looks serious.  You should put it up lol. It would be a monster.  The sun doesn't shine 24/7.

Despite living on the top of a decent hill, we get very poor quality winds here. Turbulent, unpredictable and unreliable.
Back when PV was $7-$10/watt wind made sense. Nowdays, it simply doesn't. Over-panel so even on overcast days I still get useful power has less maintenance, less complaints from idiot townsfolk, is silent and just works. In winter when we have super thick fog, PV doesn't make much, but a turbine sits there doing nothing either. I just have too much other work to do to mess about with it to be honest.
Title: Re: Blades stalling
Post by: DJ on January 09, 2017, 02:11:00 am

Reading about turbines I was lead to wonder why people still use them unless they are in an area where it snows most of the year?  If that's the case, you don't need a turbine, you just need to move somewhere decent!  :0)

I have been playing with some panels for the last couple of months and I'm impressed by what they put out under cloud. it's 7:45 Pm here and the heat has given way to clouds that look like a storm is on the way and I'm still getting 20% of what I did at todays peak in full sun which was  damn near 100% output.

Brand new decent panels can be had  here for .64c/ W. That's probably under .50C in the US.  I have bought and see used panels all the time for $50 for 250W units.
Are panels hugely more expensive in other parts of the world?

Seems to me Turbines are terribly expensive for their output and can take a lot of setting up and getting right as well then you have to maintain the things which does not seem a light job in a lot of cases.
I think I'd much rather have PV and a disel generator for the wet stretches of a fortnight or so a year when it rains non stop.

At my next house, I want to cover the thing with all the panels I can fit and do a ground array as well if need be. That might be in the form of a verandah or pergola using panels AS the roof rather than on the roof. I want to have every modern power sucking luxury and rather than cut back to save, I'll invest initially so I'm able to run it all for next to nothing in the long term.  :0)

Many people I know are paying over $1000 a quarter here.
On a years payback, that for grand would buy 20Kw of used panels.  I think that would cover most peoples household needs even on cloudy days.  Add another $1K for some used inverters and another for used fittings and wiring also readily available and you are not going to be needing much power from the grid. If you have the old style whirly meter and backfeed, you are probably going to have to keep an eye out you don't end up generating more than you use.   :0)
Title: Re: Blades stalling
Post by: TurboMiles on January 09, 2017, 06:31:16 am
Thank you for spamming this thread about my wind turbine in the wind/hydro section with your unrelated solar advice.
Title: Re: Blades stalling
Post by: niall on January 10, 2017, 05:24:41 pm
solar seems cheap now ....for sure...and i,m not up on economics , but china did seem to flood the market ..neo magnets or silicon ....they took their ball and went away with it ....neo mags got really crazy expensive  ... the big windmill manufacturers wanted them

 the small windmill aspect is  ( and its own mother couldnt love it  ) is that the local machine shop guy mike will take care of most your worries .....

i cant get solar panels in the dump.....the guts of a windmill ..well ...erm....ish...very 

Title: Re: Blades stalling
Post by: rossw on January 10, 2017, 05:38:29 pm
It really is horses for courses.

I know guys who have good, constant, almost always laminar wind, that blows day in and day out with only a few days a year of calm. That's a perfect wind turbine site!

I know of guys who live beside a mountain and have vast quantities of water flowing past them with hundreds or thousands of feet of head. That's a perfect hydro site!

Some of us are stuck with living on the top of a hill with no flowing water, the only wind we get is intermittent, infrequent and then generally destructive... but with lots and lots of sunshine. I've got a wind turbine, and it produces a bit now and then. My inverter statistics speaks far better however:
Last 365 days production. Solar: 5482 kWh   Wind: 59kWh

Not sure about you, but 150 Wh/day isn't going to even cover the inverters idle power!
Title: Re: Blades stalling
Post by: TurboMiles on January 10, 2017, 07:18:26 pm
Where I live is close to the coast, SE is my prevailing wind.  Summer months the wind doesn't blow hard but the sun shines. Winter months the sun doesn't shine much but the wind blows. Spring is good sun and good wind.
Fall is decent wind and solar. 
It makes sense to utilize both resources. 
Title: Re: Blades stalling
Post by: niall on January 10, 2017, 07:57:52 pm
same here...close to the Atlantic weather fronts ....its a kind of melancholy.... an addiction in a way
Title: Re: Blades stalling
Post by: TurboMiles on January 11, 2017, 06:56:39 am
I believe I'm addicted too ;D
Title: Re: Blades stalling
Post by: niall on January 15, 2017, 06:05:30 pm
Hughs latest books have some ferrite mags in the axial designs .....i think Proven downwind mills use them too

if your going to build an axial ..........it might be worth thinking about .....ish

i,m convinced i can corrode a Neodymium magnet .....by just looking at it
Title: Re: Blades stalling
Post by: TurboMiles on January 18, 2017, 04:41:18 am
I would use the ferrite over the neo just for the price.  Downwind design, no tail lol
Title: Re: Blades stalling
Post by: niall on February 03, 2017, 07:07:27 pm
not much help .....but theres a ferrite axial in the vid

the ferrites are very fairly big .....neos are small .....ferrites dont rust though

just a small amount of flux ... :(

Title: Re: Blades stalling
Post by: TurboMiles on February 04, 2017, 02:28:49 pm
I would like to build it using ferrite even though they aren't the strongest.  They can still be an effective turbine, Chris Olson has made many using them and are making 2kw.  I don't know all the details though.  I would also like to build the coils that will allow 110v at 450 rpm and use a classic to charge some teslas
Title: Re: Blades stalling
Post by: niall on February 09, 2017, 04:18:47 pm
yes .. go at it again

stuff rarely goes right first time ...

in the interesting times we live in maybe having your own power  is good ..........but i,m not sure what that means  :)
Title: Re: Blades stalling
Post by: rossw on February 09, 2017, 07:38:01 pm
in the interesting times we live in maybe having your own power  is good

In our part of the world, we've had a bit of a heat-wave. One state "ran out of power" yesterday and they had to urgently load-shed 100MW - so they had rolling blackouts in South Australia.

Where I am we only got to a little over 43 deg C (was still 33C at midnight and only got down to 29C overnight). We're expecting more of the same again today. (Already over 40C at midday) and the pundits are warning of more power cuts in south australia and likely in other states.

Days like this I'm glad to be 100% offgrid. :)
Title: Re: Blades stalling
Post by: niall on February 21, 2017, 05:51:42 pm
Days like this I'm glad to be 100% offgrid. :)

honestly ...i would,nt know Ross ....but i see the appeal.....on Hughs last course here all the tools were run of gens .....there was basically  no grid on site ...nor would there be thereafter 

being off grid ( for me .....sadly just for a week ) made me unhinged a bit .....but it does make you think

in a good way  :)

( looks nervously at solar panels and needs a shower )

any new plans Turbomiles ?
Title: Re: Blades stalling
Post by: Wolvenar on February 24, 2017, 07:11:38 am
Long ago now, so long it feels like another lifetime or something, I built a ferrite mag alternator that worked quite well for its parts and my lack of knowledge.
I used nothing more than "upcycled" ceramic magnetron magnets on a large disk. I could get about 750 watts from it, and it was FAR from a well designed alternator.
Most of its limitation I believe  came about from the undersized wire used in the windings, and not matching the load well, yet having more than enough blade. All turned to heat in the windings, which was it's fate. It didnt last more than a few weeks I believe.
It burned up when the batteries were low, and the wind was not. 
(http://gallery.anotherpower.com/main.php/d/19915-2/dscn2638.jpg)
This was just the initial setup to see what I could make of them.
I eventually had a flywheel on the back of this to make it sturdier.
That disk was 20" which likely helped it a lot.
Seems I cannot locate, or didn't upload any more of the pics from the project.
But yeah it most certainly can be done well with ceramics if you compensate for the lesser powered magnets.

*edit*
Going by the picture date, that was 2004.
Ouch, that's one way to make a guy feel old..
Title: Re: Blades stalling
Post by: Norm on February 25, 2017, 09:17:30 pm
speaking of old.....can't understand why I feel that way I'm only 85.....
oh by the way did you ever hook up those plastic blades you had a long time ago ?
I have plastic blades that tomw gave me gonna hook them up to 100 NiCads ....
thats about 10 amp/hrs, 12 volts
Norm
Title: Re: Blades stalling
Post by: Pete on February 26, 2017, 02:46:28 am
Wolvenar, just wondering what the output waveform from the home made generators looks like. I have one sitting in my shed that a friend left here. Long story but some lunatic did a solar/wind system for them and charged a fortune for a crap setup. Unfortunately his workmanship was such that everything he did had to be done again properly. The generator he made them was like the one in your picture but he epoxied over the coils and magnets. Did a crap job of that too and the discs are not flat, there is a big air gap. Basically I have parked it as it is not work working on.
Just wondering what the output wave looks like, and how efficient they are compared to a standard generator configuration.
Title: Re: Blades stalling
Post by: TurboMiles on February 28, 2017, 06:54:10 am
The wind turbine was converted to a down wind style to eliminate some weight.  Flying in a 15mph wind and the rotor in one piece unscrewed from the shaft.  Realizing what I did wetting I made another set of blades that spin the opposite direction.  Stood it up and out performed the best it ever had.  Wind was averaging 15mph and made 1kw in 4 hours.  Didn't think it was too bad for my baby turbine.  It lasted about 5 hours and the part of the shaft with the threads broke and again the blades went flying off.  Now there are no threads to attack anything to the generator, it could be modified by machine shop but I'm thinking I'm done with this turbine.  Thought I would share.
Title: Re: Blades stalling
Post by: niall on February 28, 2017, 03:55:38 pm
you,ve  made of lot of beautiful blades blades in a short time... :)   and thanks for sharing......its the stuff that goes wrong thats the most interesting to read

as macabre as that might seem ......

downwind machines do have their appeal ...i only tried it once and duely failed .....it was a nice thing though.....i was very attached to it at the time , i wanted it to work i guess

no tail ....whats not to like  :)