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AllanS
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Joined: 05/06/2006
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Posted: 11:28pm 04 Jun 2006

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Great site, folks.

How's this for an idea?

Get a 44 gallon drum.

Use a bit of string to mark out two 15cm wide vanes, spiraling symmetrically from the top of the drum on one side to the bottom of the drum on the other.

Cut out the waste.

Cut a single slit lengthwise down the side of some inch polypipe and slip this over the leading edge of each vane.

Wrap cotton bandage tightly from the polypipe to the trailing edge of the steel vane. This will create a helical airfoil.

Saturate the cotton with fibreglass resin.

Find the centres of the drum top and bottom, whack on some bearings, do a bit of balancing, and Bob's your Auntie.

Watcha reckon then?

(The airfoil shape wouldn't be optimal but it might work. It would be better to glue some styrofoam to both sides of the vane and rasp it to shape, but this would take a bit longer. Another possibility would be to cut some styrofoam into 15cm wide strips, run them under a hot wire to get the shape and glue this onto the steel front and back.)

makourain

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Joined: 19/04/2006
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Posted: 12:05am 05 Jun 2006

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what you said

made no sense

Gizmo

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Joined: 05/06/2004
Location: Australia
Posts: 5078

Posted: 12:38am 05 Jun 2006

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I worked it out...

Looking down from top, this shows how Allan gets the aerofoil shape. Not shown is the twist, but the windmill sort of looks like a barber pole from the side, sprial shape. The spiral means the windmill is making even power as it rotates, where a straight wing darrious has torque pulses as it rotates.

Its a good idea, would be simple to make.

GlennEdited by Gizmo 2006-06-06

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

AllanS
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Posted: 01:31am 05 Jun 2006

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Hey Makourain,

And I thought that description was a regular piece of literature! Glenn's drawing makes it clear.

I'm 2000 miles from my (very nice) workshop or I'd try it myself. I thought I'd make one today out of a plastic bucket and some hose to see if it works, but I've got distracted.

Cheers

KiwiJohn
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Joined: 01/12/2005
Location: New Zealand
Posts: 691

Posted: 03:54am 05 Jun 2006

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Sounds great, I think it might be best to fit the bearings and axle first up as the whole thing is going to get really floppy when you 'cut out the waste'.

Bandage and resin is a good idea and you could fill the blades with 'No More Gaps' once the resin hardens.

Great idea.

AllanS
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Posted: 04:01am 05 Jun 2006

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(removed those gargantuan pics)

Well, it's not the most beautiful thing I've ever made, but it gives you the idea. (Please note the patented tomato-stick axle.) Now when my wife comes home from shopping, I'll give it a whirl out the car window. Edited by AllanS 2006-06-09

AllanS
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Posted: 04:01am 05 Jun 2006

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Whoa! What's with the size of those photos?

whirlybird

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Joined: 08/02/2006
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Posted: 10:37am 08 Jun 2006

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yeh bloody pics are a bit large mate the dial up crew will not thank you.
If anyone wants to try this and I have you will find the ratio diameter to height is important it is 3 to 1.
if base is 300mm then height must be min 900mm
3 helices are better than 2
got to Google and type in Gorban Goralov you will find some interesting info there
Have fun
Whirlybird.

I am because I am.I am not always right but often I am.

Gizmo

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Posted: 10:53am 08 Jun 2006

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Hey Whirlybird.

I tried a search for Gorban Goralov but it came up with nothing, are you sure that spelling is right?

Glenn

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

AllanS
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Posted: 11:37am 08 Jun 2006

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Hi whirlybird,

So how did yours go? My bucket-turbine was something of a failure, which was hardly surprising.

Any pictures?

Gorlov turbine

http://www.commondreams.org/headlines01/0517-05.htmEdited by AllanS 2006-06-09

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