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Forum Index : Windmills : Finnish Version of a Savonius

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johnh

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Joined: 13/04/2012
Location: Australia
Posts: 2

Posted: 08:50am 13 Apr 2012

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1. I came across this interesting design for a Savonius, apparently some Finns built it.

Does anyone know anything about it ???
No Finnish jokes please!

2. Decogging F&P smartdrives.
I have a couple of 42 pole motors which I intend to build into a dual config on a single axle ( using the F&P shaft which has splines at each end )
Since I will be mounting the stators on new brackets, if I offset them by a half pole spacing, will that cancel out the inherent cogging ?

Cheers
John

To Err is Human, to Aar is Pirate

anteror
Senior Member

Joined: 06/10/2009
Location: Finland
Posts: 189

Posted: 03:06pm 13 Apr 2012

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I have not heard or seen anything about this.

You can read about vawt turbines, in Hugh Piggots latest blog;

http://scoraigwind.co.uk/2012/04/helix-wind-asset-sale/

Beatiful decoration, but nothing to do with real energy production.

Antero
Finland

shawn

Senior Member

Joined: 30/03/2010
Location: New Zealand
Posts: 210

Posted: 09:49am 14 Apr 2012

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The vawt turbines are crap yes im full of beer but it is still true! good for decoration but power production they might give a little in a hurricane but for off grid A joke!
The basics are PV (the backbone) Hawt, fun and good power in good wind.
This has not changed for a long time and will not change any time soon.

electrondady1
Senior Member

Joined: 12/02/2009
Location: Canada
Posts: 208

Posted: 01:22pm 15 Apr 2012

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that helical looks like a windside clone.

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd =1&ved=0CE4QFjAA&url=http%3A%2F%2Fwww.windside.com%2F&ei=f8a KT4mIMIfn0gGR7-SZBg&usg=AFQjCNHYDygJNlYfsJTwniUfDuhRuNdcRA

verticals just can't operate as efficiently as a hawt.
but they look so good people keep trying.

you can't put a propeller on a stick in an urban environment .
but verticals fit right in.Edited by electrondady1 2012-04-17

LeeMc
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Joined: 14/01/2012
Location: United States
Posts: 2

Posted: 04:23am 16 Apr 2012

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Hi to all, this is my first comment on here, though I've been lurking for a few months now. Just want to say thanks to all for your advise and comments and for having this site active.
I crashed one of my first simple hawts (5-5foot blades), yesterday,my fault, letting it free wheel on a gusty day I have a similar 3 blade model laying with bolts stripped out on a nearby picnic table... Whilst picking up the pieces,I almost turned to consider a vawt for my next design with my newly acquired ebay-f&p. Handily, I believe, I happened to click on this page during a break and see the candid and probably spot on advise and great comments ,ie; "..they look so good people keep trying", heheh, Thanks all, Lee

johnh

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Joined: 13/04/2012
Location: Australia
Posts: 2

Posted: 01:36pm 16 Apr 2012

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Thanks for the interesting comments.
I recognise that VAWTs can never be as efficient as HAWTs, however I am looking for a starter project for a "Men's shed" which is starting here in Moss Vale NSW.
The relative simplicity means that a working example can be created and get ideas and enthusiasm flowing.
I knocked up a simple spreadsheet ( with some assumptions ) which, I think, support a dual F&P .6mm gen setup ( overkill, yes but I have two motors )
The fun bit will be experimenting with pole mix & matching, I am thinking of setting up a test rig to evaluate the stator config - again an activity which should get some chaps in the men's shed going.
Here is a snapshot of my spreadsheet for a particular sized VAWT.

The location of the Men's shed is next to a main road so it would attract interest.

To Err is Human, to Aar is Pirate

electrondady1
Senior Member

Joined: 12/02/2009
Location: Canada
Posts: 208

Posted: 02:07pm 16 Apr 2012

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hey , don't get me wrong,
vertical drag mills are the kind i build.
most people give up too soon.
i live in town.
your restricted as to what you can do.

i build dual rotor axial flux alternators.
you put in a lot of poles to make up for the reduced rpm.
i build the stator two single phases with over lapping coils.
you can put the mills close together with out loss of power.
they work just fine in turbulent wind and they are quiet.
for drag mills, swept area is everything.
i install them along my front fence.
right now i have four identical mills up.
with two more on by bench.
i rectify each mill/phase separately and then combine the dc .

i love the way they look !

LeeMc
Newbie

Joined: 14/01/2012
Location: United States
Posts: 2

Posted: 10:33pm 16 Apr 2012

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yep, no denying that they look cool, and I would guess some relief from the ladder. My thought was to plant the fp/generator in the center of a playground style "merry-go-round" and get the grandkids off of the couch...my wife 's grumbling something about child labor laws.

yahoo2

Guru

Joined: 05/04/2011
Location: Australia
Posts: 1166

Posted: 11:30pm 16 Apr 2012

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sod the calculations, I reckon borrow or hire a sheetmetal roller and roll up a few experimental blades one night, that will kick things away.

The angle needed to give it a 180 degree twist should be simple to calculate for a specific length and diameter cylinder, the beauty of sheet is that you can roll it back flat and try a different twist just for the hell of it.

Only thing you need to know is the smallest radius that the roller can make and the length it can handle.

Get a prototype flying on a bare shaft and learn from a few mistakes, before you start on the generator, it is way more fun than getting it right the first time.

yahoo

I'm confused, no wait... maybe I'm not...

MacGyver

Guru

Joined: 12/05/2009
Location: United States
Posts: 1329

Posted: 09:53pm 24 Apr 2012

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Crew

Sorry to jump in so late. I built one similar to this about 3 years ago and I'm here to tell you two things:

Does it spin? Yes.

Does it create any power? Absolutely not!

Like someone else said, it's a nice ornament; animated yard art at its best.

. . . . . 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

govertical
Guru

Joined: 11/12/2008
Location: United States
Posts: 383

Posted: 12:14am 26 Apr 2012

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Hi, VAWTs are slow. You need a PMA that will have a high output at a low RPM. PMAs that will produce a high output at a low RPM have a high internal stator resistance. High internal stator resistance will cause the VAWT to stall. Solution, include a MPPT controller. Just a thought.
Edited by govertical 2012-04-27

just because your a GURU or forum administer does not mean your always correct :)

govertical
Guru

Joined: 11/12/2008
Location: United States
Posts: 383

Posted: 01:17am 26 Apr 2012

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Hi, video that explains why adding a MPPT controller is needed for a working VAWT.

http://www.youtube.com/watch?v=0TE38SOdf64

I was able to reproduce the results using my PMA and Buck converter circuit.

http://www.youtube.com/watch?v=B3dLzZZ5jKQ

I hope this helps. Cheers

just because your a GURU or forum administer does not mean your always correct :)

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