VAWT tower and bearings

[zander1976]

Hello Everybody,

Sorry for asking these questions but the more research I do the more I have no idea what to actually do. I have a basic vawt wing design with 3 blades like normal. That part is fine but how do I build the pole? I thought about using bearing like skate board ones but found out quickly that it was a really bad idea. I heard people talking about 2inch pvc and 1.5 inch pvc is a good option. Is that the case? If so I assume you put the 2 inch pvc pipe attached to some kind of plane ( like a sheet of plywood or something to anchor it ).  You then attach the 1.5 inch pvc to the actual blades of the vawt and insert it into the 2 inch pipe.

The 2 inch one is the female end attached to the ground and the 1.5 inch is the male that is inserted into that. How far in does it have to go. I assume all the way to the bottom ( i realize how this sounds but its not ment to be a joke ). So far so good but how do you hold the vawt up or does it just rest on the top of the 2inch pipe. Do I need a special fitting or what. I am guessing I can't just set a round sheet of plywood on top of a 2 inch pipe and expect it to rotate can I. Will it just fly away. How do I stop it from turning if I want to?

Thanks,

[zander1976]

[Volvo farmer]

A VAWT is a vertical axis wind TURBINE.  a turbine has an alternator or generator attached to it.  Once you attach an alternator or generator to your VAPW (Vertical Axis Pin Wheel) it will be easier to attach the whole thing to a pole.

[electrondady1]

what is the length of the blades and what diameter do you intend on using?
length x width will give the swept area and that would give some inkling as to what forces are involved.
even if you decide to use plastic pipe you will still need bearings.

[zander1976]

Hello,

The dimensions for the blades will be 3 foot tall and maybe 3inches wide. The diameter will be about 2 feet. The motor I have on the way is an amertec 40VDC nominal PM motor ( that will likely blow up i am guessing ). The wind speeds here get up to 60km/h plus with gusts up to 100km/h in the winter but I will test for that later.

So here are the 2 basic ideas I was thinking so far:



In the first one the whole post turns so there would need to be some kind of post on the inside attached at the top with some kind of lazy susan or some kind of bearing.

The second option is that only the windmill turns and not the post. Again the top would need to be attached with some kind of bearing and the middle would need to be as well to keep it stable.

Am I on the right track and if so what kind of bearing and how do I mount it.

Thanks, Ben

[zander1976]

Ohh before I forget. I am terrible at drawing and I know I screwed up the wings. I should just build it and take a picture, it would be easier then drawing.

[electrondady1]

the drawings are kind of charming and convey the information nicely.
use a stationary support pole .
i use bearings very similar in appearance to "skateboard" bearings.
insert them into a steel pipe and retain them with both a set screw and adhesive.
a 1/2" or 5/8" cold rolled steel shaft should be able to handle the load.

consider mounting a horizontal arm on the support pole to accommodate your pm motor.
if you mount the motor horizontally. and run it off the base plate of your mill you can dial in the amount of overdrive you can use by placing it further in or out on the horizontal arm.

[zander1976]

Hey,

So maybe something like http://www.vxb.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=bearings&Product_Code=Kit7261&Category_Code=LM attached to the top and bottom of the windmill. Then I could build a base with a 1" cold rolled pipe that could be inserted into the windmill section. Sound about right?

Thanks again. For the horizontal bar you were thinking along the lines of the closer it is to the center the slower the PM motor spins correct?

Ben

[zander1976]

Or maybe something like

http://cgi.ebay.com/10-6201-ZZ-1-2-New-1-2x32x10-Quality-Bearings-6201-Z-/220396898491?pt=LH_DefaultDomain_0#ht_1289wt_875

[electrondady1]

the prices quoted for those bearings and shafts are way out of line.
the bearings i use are about $4.00 cnd.
and a 5 foot piece of cold rolled steel  maybe 10 bucks
where in the world are you

[zander1976]

hey, PEI canada.

I was just looking at websites trying to find something that matched your description.

Thanks, Ben

[zander1976]

Hey, I found 2 bearings that look like skateboard bearings with 1/2 inch center. So I put them inside a hollow tub ( what kind of tube, like a copper or steel tube that would be used for plumbing ) and attach them to the tube. How do I attach them to the tube. Super glue or some kind of contact cement? And if I put a screw in it wouldn't I hit the ball bearings? I am a little slow I guess, I don't want this whole thing to go flying.

Thanks, Ben

[zander1976]

Here is my understanding so far

[electrondady1]

hey Ben,
 i'm from Ontario.
in fact, i live in Helena Geurgis's riding. lol
remember she freaked out in the Charlottetown airport last winter.
please don't hate us, she's goofy.and i never voted for her.

about your latest drawing, i don't know what the two steel pipes are for .
won't your wings hold things up?
i get my bearings and axles at a store chain called princess auto.
there 's one in moncton and i think two in nova scotia none on p.e.i.
you need an industrial or farm supply place.
 

i insert the 5/8"axel with  bearings,and  locking collars   inside the support tube .
i use the same pipe they use for fencing (you can get it at ronna).
its about 1.5" dia.
its welded steel tubing and has a seam inside you will need to grind off.
then the bearings will slip inside.

that works great for me but i use a bit different system than you 'cause i run a dual rotor axial flux alternator off the axel.

an alternate method would be to insert a larger  bearing in each of your disks like your drawing shows  and rotate the whole thing off your support pipe.

the key is these locking collars which need to support the weight of your mill.
good luck with it

[zander1976]

Hey,

Thanks for taking so much time to help me out. I would have completely missed the mark on this without all your help. Nah, don't worry we don't hate anybody down here..

Alright hopefully this will be my last drawing for you.. Am I getting closer:

[electrondady1]

looks like your on your way.
all i could add is the dia./strengh of your axle has a direct relationship to the mass of your mill and the wind load it will see.
you are much better off designing something  three times as strong as required than some thing that is not quite strong enough.

[zander1976]

Hey, Thanks again

The final design is:

[zander1976]

Last question for real. What do you think of using something like this as a shaft:

http://www.amazon.com/Stainless-Steel-Machine-Threaded-Length/dp/B000FMYW1G/ref=sr_1_2?s=industrial&ie=UTF8&qid=1281480193&sr=1-2

Then I could just use double nuts on top and bottom of each hub to hold them in place.

Thanks, Ben

[electrondady1]

i think it will bend and mess up your mill something fierce.

remember, after they cut the threads there's not much meat left.

cold rolled steel is stiff and meant for axles.
your going to have 3 feet of axle out in the wind with the weight of your wind mill turning at 200 rpm .
maybe it will get some ice and snow on it this winter and get nice and off balance.
you may find the pieces in the spring.

if you want , build some kind of  structural support out of 2x4 wood
retain the threaded rod in it
 it might work.

[zander1976]

Haha, cool, got to love canada

I will go with cold rolled steel..

Thanks, Ben

[DragonFly III]

I have used ceiling fan bearings for a few projects and they work quite well.  I found a couple on the side of the road and picked up others at outlet stores for a few bucks each.  The Bearings if purchased alone can be pretty pricey so I like the ceiling fan route.  They have 2 matching bearings in each one.

[zander1976]

Good to know, I am staring at my ceiling fan right now The wife would kill me for sure if I took that apart If I do run into any on my travels I will be sure to rip them apart.

Thanks again,
Ben

[electrondady1]

yes, if you check out the past postings of member "tecker" he has built a few verticals using converted fan motors on both the top and bottom .
also check out "windstuff now" on the web .
as well, there is a site that is dedicated to verticals.
 http://www.vawts.net/index.spark?aBID=125317&p=1

[DragonFly III]

I steered away from using ceiling fans for alts.  I thought in my mind that it would work but a lot of people out in the web said "don't waste your time.  I then found links where people had much success.  Can't expect the world out of them but they do produce power. 

I wish I knew this when I started building my mini-mill. 
That is a 3 blade helix VAWT which rides on two ceiling fan motors with the stator removed (two bearings on each side).  (I sold the copper to a scrap yard)
I could have left the stators and had an alt on top and bottom. I would think I would have wired them in parallel to increase the power output.

So I guess that is another approach for you.  Or if you would rather stay with an add on alt, just use the whole assembly for your bearings and run the shaft through them.  If I remember correctly the bearings have a 5/8 shaft. 

DFIII