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#Post#: 6100--------------------------------------------------
Aluminum Bladed VAWT
By: lynx wind Date: February 22, 2016, 10:42 am
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We had a very strong wind storm a couple days ago. The VAWT
that SUT built has been up and running for a year and half at
least and has powered many of my small appliances. It
catastrophically failed during the windstorm. What happened was
one of the wood rings that tied and supported the blades top and
bottom broke. The rings were made from 3/16" plywood so to last
so long is testament to the design.
When the ring broke basically everything disintegrated and flew
off 50 feet. Each ring was broken at the blade. But remarkably
each blade was fine.
Had the rings been made from a stronger material the turbine
would have been fine. But keep in mind this was a test
prototype and passed the test with flying colors.
Rather than rings the blades could be tied by straight line
aluminum or stainless steel strips about 1/2" wide. I also
think full length spars is a necessity. I didn't witness the
turbine's demise but it could have been a blade pulled away from
its short internal support and would have caused the same total
failure.
I didn't take pictures, but imagine rotor blades still with
their blades supports attached, 6 unscathed blade sections
scattered all over the yard and six broken ring sections
scattered all over.
This turbine could easily be rebuilt with a couple plywood inner
ribs, full length spars and straight blade supports.
#Post#: 6101--------------------------------------------------
Re: Aluminum Bladed VAWT
By: sut Date: February 24, 2016, 8:19 am
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Thx for the update @ LW
Truthfully I an surprised it lasted this long, while building
it I ran into many problems and had to modify things along the
way . The biggest problem is adhesive to hold the former into
the wing, although goop works pretty good . The trouble is when
sliding the former into the wing most of the goop is scraped off
making for a weak glue joint . I agree that a solid through spar
is needed but it needs to be light weight, I have been thinking
about using 1/2 pvc pipe for the though spars and top/bottom
ring and also eliminating the former's and just screwing/gluing
the wing to the pvc pipe on leading edge .
#Post#: 6102--------------------------------------------------
Re: Aluminum Bladed VAWT
By: sut Date: March 11, 2016, 8:20 am
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Thought I would show everybody my new test windmill with pvc
pipe & aluminum wings its 30 X 48 . The wings don't have any
formers in them just the pvc pipe attached to leading edge of
wing, we will see if it will stay together. The top supports are
pvc pipe also, flattened on ends and holes drilled through to
attach to the pvc pipe in the wing . Now all I need is wind !
HTML https://drive.google.com/open?id=0B5KUgNgaszekRExITFVwVlBxNUk
HTML https://drive.google.com/file/d/0B5KUgNgaszekVG84MXFCb3c1eDg/view?usp=sharing
HTML https://drive.google.com/file/d/0B5KUgNgaszekT25iMndQQUt6M1U/view?usp=sharing<br
/>
#Post#: 6103--------------------------------------------------
Re: Aluminum Bladed VAWT
By: sut Date: March 16, 2016, 5:35 pm
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Well its spinning but it came apart today! glad I was there to
stop it from destroying it's self ! It seems to be stable and
running true but I need to ether use 1 long pipe for wings or
glue them in.
HTML https://drive.google.com/file/d/0B5KUgNgaszekMExrV0xGa29SSkE/view?usp=sharing
#Post#: 6112--------------------------------------------------
Re: Aluminum Bladed VAWT
By: maximoney1 Date: April 17, 2016, 5:17 pm
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SUT appreciate all the effort you have put into these projects
and enlightened by both your successes and the failures. Only
when you start building these things do you realise, all the wee
niggly things that can go wrong, so thanks again.
#Post#: 6232--------------------------------------------------
Re: Aluminum Bladed VAWT
By: sut Date: January 28, 2017, 2:00 pm
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I finally got some time to experiment with this PVC windmill !
Ive had it up for almost 1 year but it wouldn't turn very much
with my limited wind. Now its turning with just a hint of wind
,what I did to it was lighten it up by 5 lbs by removing the
wooden rotor and just fastening the PVC arms directly to the
magnet plate. I also removed the top and bottom wing supports
just for this test . My thoughts are just to let it bend out of
shape on high speed and see what it does, hoping it will just
slow down and return to shape with out hurting anything. below
is a link to see it in very light wind (not even enough to mess
up your hair )
HTML https://drive.google.com/open?id=0B5KUgNgaszekTkF3eDVNSkEtSTQ
#Post#: 6233--------------------------------------------------
Re: Aluminum Bladed VAWT
By: lynx wind Date: January 31, 2017, 11:32 am
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That is interesting that lightening it helped so much. I
wouldn't think some weight would be a big issue once moving.
It's getting the weight moving that takes energy. Are you sure
you didn't change the angle of the blades?
I am experimenting with doing away with rib formers and placing
two spars at LE and TE. I din't notice you doing it but started
doing it with paper models and bamboo skewers. And then i
thought about the aluminum blades and just forcing them over two
spars. Works nicely.
Keep up the experimenting and keep reporting!
#Post#: 6234--------------------------------------------------
Re: Aluminum Bladed VAWT
By: Bassman Date: January 31, 2017, 2:09 pm
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[font=times new roman]I can see how it happened, if there is no
ball in the bottom of the brass nipple.[/font]
#Post#: 6235--------------------------------------------------
Re: Aluminum Bladed VAWT
By: sut Date: February 1, 2017, 8:47 am
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Well I don't think I changed the angle of the wing but will
check when I take it down to add the wing tips and blade
supports . My thoughts on not having any former's and just 1
spar in wing is may be it will cause the wing to straighten out
a little on high speed and cause it to change shape and the lift
of the wing causing even better TSR. Now I don't know how much
flexing of the aluminum wing it can take without making a
permanent bend in the wing or metal fatigue. Another thought
about the weight making such a big change is not the weight, but
the wind not having to go around the flat rotor.
#Post#: 6236--------------------------------------------------
Re: Aluminum Bladed VAWT
By: sut Date: February 2, 2017, 8:44 am
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OK i measured the wing angle and it was changed ! So now its +
1/2" to the TE, instead of - 1/2" to TE so wing TE is further
out than LE of wing .I have no Idea how this will affect the
windmill (high speed ) but its turning better than before, at
least in light wind. What happened is that when I removed the
wood rotor and attached the PVC directly to the mag plate I used
existing holes in mag plate which made the PVC angled backwards
by 1/2" from square to the mag plate center.
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