Author Topic: Light Weight Wind Turbine Project - as I build it. (Read 248355 times)

SparWeb · « **Reply #231 on:** April 17, 2012, 02:43:00 PM »

I built a mast like that for a two (2) foot diameter anemometer. IT WAVES AROUND IN THE WIND. I repeat: 2' Diameter, anemometer, 6 feet protruding up. And even so it's a bit too flexible to be a good anemometer mount, but heck it was cheap and convenient. But obviously anything more would too big.

You have built the same thing for a 7 foot diameter wind turbine.

You're begging for the wind gods to smite you.

This won't be safe. It will take much less than one storm to bring that down. It probably won't survive the winching up. Pipe threads cannot withstand bending. If they stand up for a while, they won't last, as the cut-threads fatigue and crack through.

Put an anemometer or a flag on that pole, then go and built a tower with some hair on its chest.

Problem #2

Comparing a sheet metal WT blade to an aluminum aircraft propellor makes no sense. Get a reality check: Would you make a chair out of cardboard? Of course not! Even if you try and it works, there is no way to reasonably pretend that one is more durable and safe than the other. But they're both wood fiber, you say? Now you're justifying the ridiculous with the irrelevant.

sean_ork · « **Reply #232 on:** April 17, 2012, 02:49:18 PM »

Quote from: SparWeb on April 17, 2012, 02:43:00 PM

Would you make a chair out of cardboard?

sorry .......

windvision · « **Reply #233 on:** April 17, 2012, 03:07:52 PM »

Steadfast:

Asparagus juice and cardboard chairs aside, are you putting this turbine on your house insurance policy? Is there a waiver for doing things like this? Just checking...........

thingamajigger · « **Reply #234 on:** April 17, 2012, 03:09:20 PM »

@Steadfast
I took a look at those falcon blades and my advice as an engineer is to run away, run forest run.
Basically there are so many things wrong with those blades I don't even know where to begin, first it is sheet aluminum which looks like it was bent with a brake which means the outer span along the bend acts like a partially angled "I" beam making it more rigid along that axis. Unfortunately this more rigid axis lines up near perfectly with the most feeble point of attachment I have ever seen. Basically they have made the whole of the blade more rigid so it acts like a big old lever acting on a few small bolts through relatively thin material -- the person who designed these blades has literally no idea what they are doing in my opinion. They will fail at the root most likely at or near where they drilled holes to mount them to the hub.
I'm sure this would work ok as a truck radiator fan or maybe a fan to cool a greenhouse but it is the last thing we want for a wind turbine.

There is a reason wind turbine blades are thick at the root and thin at the tips and it relates to the stressed skin concept. That is the skin wants to stretch on the front side and compress on the back side when encountering a force or bending moment. As well it is not common knowledge but even with wood blades this concept applies because the majority of bending strength is found near the surface of the material and the inner material is for the most part filler to prevent buckling due to compression, it does add strength concerning the radial acting forces but very little to forces acting to bend the blade. This is because wood is basically a natural laminate and the inner portion still acts somewhat like a thin blade despite the material around it which is why thicker material places more material away from the central axis along which it bends which makes it stronger. This is also why big wings and blades are thick and hollow because the inner material adds a great deal of weight which is bad but very little in the way of actual strength.

Here is an easy way to prove this matter for yourself, take a ruler or yard stick and place it flat(horizontal) on a table with one half hanging over the edge. Now try to bend it downward, it bends very easily because the material is thin. Now place this thin ruler vertically on edge and try to bend it downward, well it will not bend at all and this is because despite the fact it is still "thin" there is still a great deal more material further away from the central axis along which it bends under tension and compression.

In any case I would take some old 2 x 4 blades cut down by a drunken man on a rusty table saw before I would touch these blades with a ten foot pole.

klsmurf · « **Reply #235 on:** April 17, 2012, 03:25:32 PM »

About 6 weeks of fly time. Often reaching 900+ rpm. 4 foot diameter.

DamonHD · « **Reply #236 on:** April 17, 2012, 04:02:35 PM »

Goodness, I know we sound like a bunch on nay-sayers in the pub, probably in our 80s, but we would like you to have a successful outcome and no injuries or worse.

I feel twitchy enough about solar panels (hey, I just got another 17kWp installed on the local school's roof, with the second half going live today) and their ballasting and so on against wind.

Rgds

Damon

Steadfast · « **Reply #237 on:** April 17, 2012, 05:22:19 PM »

What all your anti-aluminum warnings boil down to, regaurding my already purchased Falcon blades, is that I am just going to have to do a maintenance check on the blades' condition once every month to search for stress marks. Got it! thanks!
Cool, I can report those results here too!

Here is an additional idea to contemplate:
Perhaps I can increase the thickness and strength by screwing on a reinforcement steel plate onto each blade, where they attach to the hub to minimize the flex and vibrational damage...
or

Perhaps I can go the opposite direction, by adding a rubber gasket between the hub and the blades, and by also adding a thick rubber washers to My bolts, so the blades will be held firm and yet be able to "flex-away" some of the destructive force of the vibration...

Hhhm... Perhaps both....

fabricator · « **Reply #238 on:** April 17, 2012, 05:30:01 PM »

Quote from: klsmurf on April 17, 2012, 03:25:32 PM

About 6 weeks of fly time. Often reaching 900+ rpm. 4 foot diameter.

I'll bet that's 6061 T6 "Aircraft grade" aluminum right? Aluminum, no matter the grade just like every metal work hardens when stress is put on it, work hardening WILL cause failure at some point, every aluminum skinned air craft after a certain number of rotations has cracks in it's skin and they are constantly inspected, remember the airliner that was flying out of Hawaii when a large portion of the cabin roof blew off? That was caused by metal fatigue or work hardening.
They are constantly changing out parts on airlines for this reason.
Air craft aluminum does not mean indestructable it only means it will survive more stress induce work hardening than ordinary
3003 aluminum will.

sean_ork · « **Reply #239 on:** April 17, 2012, 05:38:20 PM »

Quote from: Steadfast on April 17, 2012, 05:22:19 PM

What all your anti-aluminum warnings boil down to, regaurding my already purchased Falcon blades, is that I am just going to have to do a maintenance check on the blades' condition once every month to search for stress marks.

do you have some xray specs ?

to be honest, having remembered that you have very little wind in your area, you'll get away with a a blade inspection every time you see an amp flowing into your 12v battery - you may wish to apply a far more rigorous inspection schedule to your ''tower''.

ghurd · « **Reply #240 on:** April 17, 2012, 06:10:36 PM »

Quote from: Steadfast on April 17, 2012, 05:22:19 PM

Here is an additional idea to contemplate:
Perhaps I can increase the thickness and strength by screwing on a reinforcement steel plate onto each blade, where they attach to the hub to minimize the flex and vibrational damage...

A decade ago, that was commomnly called "Mike Mods".

Blast from the past, Feb 2005, Jerry's pic,

fabricator · « **Reply #241 on:** April 17, 2012, 06:45:59 PM »

I'd almost be willing to bet with all this exposure, you will likely get a refund and never see the super delco.

CraigM · « **Reply #242 on:** April 17, 2012, 06:48:00 PM »

Steadfast, From one newbie to another, thanks for being the guinea pig, sacrificial lamb, test subject, etc. through this build of yours. The hard work and time you've invested in this has been a great learning tool for myself and most likely many others. Everyone on this board has traveled this same path of learning at some point and I'm sure they've tripped, fallen and stubbed toes along the way. Thing is I'm guessing many of them weren't put under the same scrutiny as you have beenâ€¦ my hat's off to you for hanging in there.

I'm tripping along the path behind you, kicking rocks along the way and trying to discern the good stuff from the crapâ€¦ now where is that god awful smell coming from?

Scraping my shoes and trying not to step in it againâ€¦ CM

JW · « **Reply #243 on:** April 17, 2012, 07:58:55 PM »

Great job finding that picture Ghurd...

ChrisOlson · « **Reply #244 on:** April 17, 2012, 08:05:34 PM »

Quote from: Steadfast on April 17, 2012, 01:57:06 PM

I plan to attach the wench to a 6ft long, steel â€œHâ€ girder, sunk and concreted into the ground 5ft down.

Have you told your wife about this plan?

--
Chris

ghurd · « **Reply #245 on:** April 17, 2012, 08:08:56 PM »

Pretty sure 2 or 3 of my toes are broken at any given moment.
The 4th toe on my left foot is always purple, and has been for a few years. Not kidding. Not sure if it is related to reworked delcos.

We are not saying "don't think".
We are not saying "don't try".
We are not saying "don't experiment".
We are not saying "don't post".

We are saying car alts, and many other items, are almost always a serious drain on a newbies cash flow with no positive results.
Research before spending money.

fabricator · « **Reply #246 on:** April 17, 2012, 08:57:43 PM »

One more thing, the word is WINCH, a wench was usually a working girl in in the pubs England and the Taverns in the colonies.

thingamajigger · « **Reply #247 on:** April 17, 2012, 09:27:08 PM »

@Steadfast

Quote

What all your anti-aluminum warnings boil down to, regaurding my already purchased Falcon blades, is that I am just going to have to do a maintenance check on the blades' condition once every month to search for stress marks. Got it! thanks!

If you already have the blades and want to try them then there are a few things you can do to fix the issues they have. The main reason they fail is that the bolts/holes are considered a point load and all forces are essentially concentrated into and around this relatively small area. A force concentrated into a small area is a large force and the same force spread over a large surface area is a small force per unit of area. This means you could cut two 2mm stainless plates, say 8" x 2" with rounded corners or 4mm aluminum of the same area and compress the blade between them. As a gasket I would use 2mm fibrous material often used in the automotive industry because it has a high shear strength and is usually a medium to high density material. Think of the gasket as a kind of clutch plate which is compressed onto the blade between them, we need compression or friction to limit the slip which is a bending moment introducing tension and we need a certain amount of rigidity so that the forces are spread evenly over the entire surface of the plates.

If you just bolt on some plates the blades will simply fail at the end of the plates, if you add soft fat rubber gaskets then the forces will still concentrate around the bolts in a slightly larger area. We want all the forces spread evenly over the plates with no concentrated forces at the edges or the point of attachement at the bolts. As well it matters "where" the bolts are located because the forces are not only spread out around each bolt but between them as well so the bolt pattern must be evenly spaced to be effective.

I'll tell you what, when you get your blades post front and side views of where they attach to the hub next to a ruler or other means to measure the scale and I will do some quick CAD plans of what you need to do to fix them. I may even do a solidworks stress and flow simulation on them if I have time so you can see visually how all the force concentrates at or near the bolts.

niall2 · « **Reply #248 on:** April 17, 2012, 09:30:19 PM »

not a way to win friends , but the elephant in the room is hurricane wind power...

their google hit count must have improved a lot in the last week ....nothing to do with you Steadfast
you just want to experiment like all of us ....but ...theirs no such thing as bad publicity , especially with the growing trend of cheap grid tie inverters ....

to be fair to hurricane ..all the other ebay/utube Sellers should get their speak too ......thats the democratic way ...

Steadfast · « **Reply #249 on:** April 17, 2012, 10:29:51 PM »

Thanks... This is precisely why I post all my projects this way in "as I do them" format. You see, I have learned that most of the time it is easier to learn how to jog from a man who guilelessly stumbles along and finally finishes well, than from a seasoned marathon athelete who is too fast to even try to keep up with. If you like this kind of discovery process that I do, than you should really see my bronze work links I posted earlier in this topic.

Quote from: CraigM on April 17, 2012, 06:48:00 PM

Steadfast, From one newbie to another, thanks for being the guinea pig, sacrificial lamb, test subject, etc. through this build of yours. The hard work and time you've invested in this has been a great learning tool for myself and most likely many others. Everyone on this board has traveled this same path of learning at some point and I'm sure they've tripped, fallen and stubbed toes along the way. Thing is I'm guessing many of them weren't put under the same scrutiny as you have beenâ€¦ my hat's off to you for hanging in there.

I'm tripping along the path behind you, kicking rocks along the way and trying to discern the good stuff from the crapâ€¦ now where is that god awful smell coming from?

Scraping my shoes and trying not to step in it againâ€¦ CM

Steadfast · « **Reply #250 on:** April 17, 2012, 10:45:10 PM »

Oh yeah... the reason I have stuck with this here, in spite of the random beatings, is because I know that wisdom is found in a multitude of counsellors. And most all of you here have proven to be very knowledgeable counsellors and correct on many amazing levels. Which I will not mention spacifically because your prideful heads might inflate to explosive levels and you are in bad enough shape already....

I like wenches.... a lot... what's wrong with wenches....

BTW: do any of you folks know a clever way of getting a power cord down a tower pipe? Between the internal pipes and the bolts that are holding them in place there is not much possibility of simply pushing my power cord thru... and yes... I have several ideas of my own... but I want to hear your ideas first...

And yes I am interested in thingamagigers help with my blade mounting longevity challenge.

birdhouse · « **Reply #251 on:** April 17, 2012, 11:46:57 PM »

Quote

BTW: do any of you folks know a clever way of getting a power cord down a tower pipe?

get some string, and tie a small chunk of plastic bag to it. insert it in one side of the tower pipe. insert shop vac into opposite end of tower pipe. suck until plastic bag chunk comes out. tie wire to string, pull wire through.

this is very much why i don't like through bolts through towers. ARE turbines had trouble with shorts from through bolts rubbing through the insulation, and all their stuff was engineered!

adam

Steadfast · « **Reply #252 on:** April 18, 2012, 07:56:19 AM »

Brilliant... but I don't own a shopvac.

I have been told that Tony at hurricain needs 2-3 more weeks to work the kinks out of th new PMA design. Most of the problem is due to challenges milling out a new spindle set up that will hold the new eliptical magnents. Bummer...

So... my next major post will be of us installing the WENCH, the cables and inserting my electical cord down the pipe. This should happen Saturday. (photos posted that evening).

birdhouse · « **Reply #253 on:** April 18, 2012, 09:03:15 AM »

you can also go buy a fishtape. they're designed just for what you're doing. or put the money into a shopvac, as you'll probablly get more use out of the shopvac!

Bruce S · « **Reply #254 on:** April 18, 2012, 09:46:27 AM »

Actually I'd like to see the "wench" on the 6 foot pole

.
I'd particularly like to see the wench from the Saint Pauly beer label on that 6 foot pole. I'll help hold the ummm beer(s)

With due respect to CraigM.

Most of the people posting here trying to help, have been subjected to much worse out-right name calling ( which we won't get into).
In my testing of alternative batteries, I've blown up a few, posted them here for all to see.
YES, we were all newbies at one time and paid the dues in money, time and some even painfully so.
Steadfast we behind your tenacity and applaud you for it.
Cheers;
Bruce S

Steadfast · « **Reply #255 on:** April 18, 2012, 10:17:08 AM »

Quote from: Bruce S on April 18, 2012, 09:46:27 AM

Actually I'd like to see the "wench" on the 6 foot pole .
Cheers;
Bruce S

Hey now, woe, slow down there buckaroo!

For me to pull THAT off,
I'd have to call my wife a "Wench" to her face, and not only survive that encounter, but also "get lucky" with her too.

THEN I'd have to be an anatomical freak at the same time...

Then there are those annoying rules against posting homemade porn here... Ect Ect Ect...

but hey, I digress

Steadfast · « **Reply #256 on:** April 18, 2012, 10:26:35 AM »

Quote from: Steadfast on April 18, 2012, 07:56:19 AM

So... my next major post will be of us installing the WENCH, the cables and inserting my electical cord down the pipe. This should happen Saturday. (photos posted that evening).

YIKES!!!
I just reread THAT one and have just realized how MUCH it could be taken out of context...
Ha ha ha... WOW!

ChrisOlson · « **Reply #257 on:** April 18, 2012, 12:32:48 PM »

I sort of wondered if your wife was going to approve of strapping some babe to a H girder out in the yard

--
Chris

Steadfast · « **Reply #258 on:** April 18, 2012, 12:52:20 PM »

Quote from: Bruce S on April 18, 2012, 09:46:27 AM

I'd particularly like to see the wench from the Saint Pauly beer label on that 6 foot pole. I'll help hold the ummm beer(s)

OK....
Here yah go!

and you thought watching a wind turbine spin was interesting...

Bruce S · « **Reply #259 on:** April 18, 2012, 01:24:05 PM »

Now all we need is a breeze to blow steadily

.

ChrisOlson · « **Reply #260 on:** April 18, 2012, 01:25:40 PM »

Jennifer England on a stick

--
Chris

CraigM · « **Reply #261 on:** April 19, 2012, 12:14:16 AM »

Hope I wasn't taken wrong, "Remember, I'm pulling for you. We're all in this together" - Red Green

fabricator · « **Reply #262 on:** April 19, 2012, 07:47:54 AM »

Red could do it all with a case of duct tape.

Steadfast · « **Reply #263 on:** April 19, 2012, 01:25:33 PM »

If I am to shoot a video of this turbine's abilities what sort of digital meters do you guys suggest I buy to best display clearly and LIVE what is coming down my line. I suppose I would prefer somthing with a lighted display that shows volts, watts and amps simultainiously. something I could install into my power board.

and I dont want to pay a fortune for it!

I was looking at this one:

"Watt's Up" RC Watt Meter & Power Analyzer WU100 Version 2
Price: $54.00 at Amazon
link:
http://www.amazon.com/Watts-Meter-Analyzer-WU100-Version/dp/B001B6N2WK/ref=acc_glance_hi_ai_ps_t_1

or This One:

Volt Meter/DC Digital LED Amp Volt Meter + Shunt /200V 200A /Blue
Price: $11.49 at Amazon
link:
http://www.amazon.com/Volt-Meter-Digital-Shunt-200V/dp/B005HBBZEM/ref=sr_1_7?ie=UTF8&qid=1334856945&sr=8-7

News:

Author Topic: Light Weight Wind Turbine Project - as I build it. (Read 248355 times)