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Post InfoTOPIC: Poly - Helix Vawt
CmeBREW1



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Posts: 30
Date: Feb 4, 2010
RE: Poly - Helix Vawt

For the 8 cross support arms, I just used bent SOLID 1/2" rod around a plywood form with a piece of steel at one end to hold the rod as I bent it around the form. (The form is actually two pieces of plywood screwed together)

I also used a short piece of pipe to give me more leverage to bend them.
I bent the first one, and then tried to bend the other seven as close as I could to the first one.  Gladly, They turned out fairly the same.


Next, I welded these 8 cross support arms to the Main 1" (ID) Center pipe using a piece of angle steel with a couple clamps.  Made it easy to do.
It was unwise, but I just guessed at the twist angles to turn each set of cross supports. I couldn't think of an easy way to do this, and am certainly no Geometry teacher!

It turned out OK, but I found out later, at the end, the twist is much steeper at the bottom and not that much twist at the top section.
It probably don't mean that much, but I'm still not sure.
What's important is that both SIDES are EQUAL with each other, which they are.

BTW.  I said earlier the swept area is 18Sq. feet. -- but that is incorrect, it is actually closer to 20 Sq. Feet.   (6ft. by 40 inch diameter)



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CmeBREW1



Veteran Member

Posts: 30
Date: Feb 4, 2010
RE: Poly - Helix Vawt

The pole is just a 16 foot long treated 4x4 ($18)  reinforced with a couple 2x4's at the bottom section, and then it is cemented into the ground.  And a couple more 2x4's for the support arms with a piece of decking board for reinforcments. 

Making this and cementing it into the ground only took me about 6 hours. That part was easy.  (Photo below)

The next part was not so easy.  The steel blade rotor.
It starts with a 1/4" thick steel disc drilled for the trailer hub -- and I welded a 6 inch piece of 3/4" SOLID rod from both sides into the disc.  Of course I drilled the 3/4" hole first.  The piece of Solid Rod must be perfectly plum since that is what I later weld a 6" long piece of 3/4" (SCD 40) black pipe over -- and then finally, I weld the MAIN 1" (ID SCH 40) black pipe. 

It is a little loose, with the pipe over pipe method, but using a little piece of aluminum flashing wrapped around the inner pipe makes it good and straight for final welding.

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CmeBREW1



Veteran Member

Posts: 30
Date: Feb 3, 2010
Poly - Helix Vawt

Hello Vawt folks,

       Well, here it is, my first attempt at a Helical Vawt using a 12 foot long Polycarbonate panel cut in two with my tin snips.
Swept area is about 18 Sq. feet.

I am very excited about this one because it is exactly the way I envisioned it. 

It looks really neato I think.  I just put it up a few hours ago.  Took me two days of welding since I had to weld on the floor since there was no bench big enough. (my poor back!)

I have a lot of photos to show but I do not know if there is a limit to the size or not.  I have numerous 20-30K size photos.  Under 10K does not show much detail.

Here are the main photos of it up and turning slowly. Almost no wind right now, but it is turning 40-60rpm in almost nothing. (3-4mph)


I borrowed my brother's digital camera and made an initial little Video on Youtube, but the quality was set low, and I will have to ask him later how to set it to max resolution for a good video on a decently windy day soon.

http://www.youtube.com/watch?v=i4oz1UtY9AY


I will keep adding pictures and comments of how I made it.
I really believe it will do a hundred watts in a big wind when a windy day comes back around soon.


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