Light Weight Wind Turbine Project - as I build it.

[CraigM]

I've found this page on tower construction to be very informative. http://www.otherpower.com/otherpower_wind_towers.html

Here's a short excerpt taken from this page;

"The drawing above shows some thoughts about how to build a pivot from pipe. The one pictured would be very strong - I've made much lighter duty ones that worked fine. It needs to support the weight of the tower - thats all. The foundation on which the tower/pivot sits is also not a big deal. Much more important are the guy wire anchors. A simple metal 'foot' that can be staked down will suffice for the tower, because all the force is straight down. Main thing is that it cannot slide easily, and that it doesn't sink into the ground. If it sinks it will cause the guy wires to loosen. So, a small concrete pad might be a nice tower foundation, but it's not required."

So as I understand this 1000 lbs. of concrete does very little for you except make your wallet lighter. A simple pad that doesn't slide or doesn't sink under the weight of the tower is what you need.

CM

[Steadfast]

here is  how bent the winch stand became:


Here is a photo of the new setting foundation, which is just as deep as it is wide:

[keithturtle]

"Where can I find a round plastic wall into which I can pour concrete to also set above ground?

Here's the tower base I poured.  There is an elaborate latticework of rebar going down several feet, welded to the bolts; but I needed a ring to act as a concrete form.  I sawed a plastic 55 gal drum and made a ring from that.  It was too small diameter, so I sliced the ring and bolted in another section of the drum to make the right size.   Worked well, cain't find the pic of the process.

Pay no attention to the steel

Turtle

[SparWeb]

Try something like this for your winch:



Threaded rods go down 4 feet.  Criss-crossing them are a christmas-tree of re-bar at right-angles, held together with baling-wire.  The top is square because of the form I used at the top, however underneath the form didn't go all the way down.  I also believe in letting some ground moisture seep in and slowly cure the concrete.  I also "squirt" the top of the concrete pad while it sets, every few hours or so.

My tower base was a massive-overkill so I won't hold it up as an example.

[birdhouse]

steadfast-
i really hope you're concrete tower base holds, but the pictures aren't inspiring. 

this is coming from a guy who has put a few million pounds of concrete in the ground/forms for various projects/work over the years...  tens of thousands of pounds hand mixed.  i've put ~200,000 lbs into forms in a day. 

it's very tempting, and easier to add excess water to bag mix, but it is a REALLY bad idea for anything but fence posts.  judging from the photos alone, it looks like you had a 1000 lb soup fest.  NOT good for strength.  especially without rebar.  far better would be a consistency similar to mashed potatoes...  kinda sticky, yet fully wetted out. 

so like i said, i really hope you're concrete tower base holds, but i have my doubts about a non-rebarred soup fest. 

google "slump test" and you'll learn more than you probably care to know about concrete. 

adam

[fabricator]

This question was asked earlier but got no response, and it could be the answer to this whole tower fiasco, are you using a gin pole?

[Steadfast]

nope.... mono pole...

[SparWeb]

nope.... mono pole...

Uh oh.
Somebuddy's gonna get a whuppin' behind the woodshed.

[CraigM]

I'm seeing two different approaches to how a tower base should be constructed and I'm a bit confused.

The Dan's at Otherpower http://www.otherpower.com/otherpower_wind_towers.html say “It needs to support the weight of the tower - thats all. The foundation on which the tower/pivot sits is also not a big deal. Much more important are the guy wire anchors. A simple metal 'foot' that can be staked down will suffice for the tower, because all the force is straight down. Main thing is that it cannot slide easily, and that it doesn't sink into the ground.”

Yet others that have posted here have a much more robust tower base with lots of reinforcement. Although I'm not sure of the size of their towers.

I understand frost heave and the importance of placing a foundation below the frost line but where the Dan's are located I'm sure they need to deal with frost and yet this doesn't appear to be an issue.

So what gives? With the size of tower/turbine that Steadfast is using what is really needed for the tower base? As long as a gin pole is used to raise and lower the tower.

[Steadfast]

That is what I gathered from dan's book too...

Heck,
I would not have bothered to add all that extra concrete had mine not snapped and messed up the use of the hinge and thus way in went up and down.

[SparWeb]

@CraigM

It depends on how you deal with the "kick" load on the ground and how to join the gin pole to the tower, if at all.
Dan also gets away with bars sitting flat on the ground because his soil isn't soil, it's rock.  The effort of digging a hole for a foundation is enormous in the mountains where he lives.  He can dispense with the foundation because a few steel stakes in the rock will do him just fine.

I have the opposite situation.  I live in semi-arid flat prairie, and my soil subsides is you pile weight on it.  The mass of my tilt-up 3" pipe tower, plus guy cable tension X 4, is several thousand pounds.  I need a lot of surface area supporting the weight to keep the "PSF" pressure down.

Back to the "kick" load I mentioned before.  When you start lifting the tower with the gin pole, you are pulling in a cable which is, nearly, horizontal.  Going back to basics, you have to exert 1000 pounds on the ground sideways in order to exert 1000 pounds on the cable in the opposite direction.

That force carries through the towing cable to the tip of the gin pole, and on through the next cable between the gin pole and the tower top.  This system is in balance because the weight of the tower X height of the tower is = to the tension in the cable X length of the gin pole (in concept, skip the details for now).  The weight of the tower rests on the foundation by pushing down on the foundation.  The tention in the towing cable rests on the gin pole but pulling sideways.  The the tower base doesn't slide toward you because the foundation also resists sliding on the ground.  The base must not slide on the ground or else the tower will overturn its foundation.  That's the "kick" load that I'm talking about.

Dan doesn't need a foundation for that, because he's staked his base into stone.  I'm not so lucky. 

Steadfast is breaking all of these rules.  If he's not using a gin pole, or not spacing his tow cable away from the tower pole at the very least, then all he's making is pretzels.  Without more information I can only imagine the worst-case scenario.

[tanner0441]

Hi

Correct me if I am wrong but.... Is you tower base just sitting in the kitty litter tray and not into the ground below it? If so the distinct lack of mass and friction will skid the plastic out of the hole. You can see the forces on your winch pole. When the pole bends so far the forces on the pole become tensional, and it all depends on your ground consistency as to whether it stays there.

I am lucky that all the masts I worked on were all installed professionally but you would be surprised how much they wobble about at the top, it makes you think the first few times you let go with both hands and rely on your harness with 100ft of fresh air below you. Those masts were erected with a crane and the guys were fitted as you went up. but the concrete in the bases was very impressive, and a sample of concrete had to be cast into a mold and sent for testing before we put any antennas on it.

My own mast is only 30 ft 3 in dia sectional pipe at the base the mast sits against a 3ft high wall and I use a power winch attached to a big tree stump, about shoulder height so the winch cable and the mast were never both close to parallel as it nears the ground.  Read up on over centre forces..

Brian.

[Steadfast]

GUYS...Guys...
The title of my project is "Light Weight Wind Turbine Project - as I build it."

emphisis on "Light Weight"
(say around 20 pounds max for the whole bird)
emphisis on"5 to 7 ft blade span"
emphisis on "Cat 1 wind region"

It is only a 30 ft tower.
firmly attached to my shed at 10ft up and
Im Adding in guy wires at 20 ft
The pipe itself is also two pipes thick, one inside the other, Staggered for strength!

Sheesh... 
I think the "johnny come latelys" need to re-read this string from the beginning... 


------
yes tanner your wrong.... look at the photo....
The kiddy pool was used as a wall mold to build UP the concrete above the ground.
the lip of the pool is actually level with the ground.
The concrete is also filling a big hole below it.

Here is a photo of the new setting foundation, which is just as deep as it is wide:


It only appears to be buried more deeply, in the picture, only because we piled up dirt around the pool to hold it in place while we poured...
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[birdhouse]

GUY...  guy...

you are talking about a twenty pound weight, thirty feet up on a tower that has zero engineering behind it, that has been potentially poorly ban-aided together, while trying to raise it without a gin pole. 

you're breaking almost every single rule in the safety realm and now you're wondering why we are trying to help, make it safe, have you not kill yourself? 

you've already had two failures (winch support, and tower base).  when is the next failure going to happen?, and who is going to get hurt because of it?   just because it's a small turbine that doesn't weigh much, doesn't mean the tower can be weak and prone to failure!  a 20lb weigh moving at 9.8m/s toward a human can really put a damper in your day!

you're playing with fire, and there doesn't appear to be a garden hose anywhere near! 

i'll admit, i never engineered my 70' tower with a 100+ pound machine on top, but i did do A LOT OF RESEARCH on other towers used for similar purposes that were engineered.  i can feel really good about that, and my tower has always felt very robust during the raising and lowering process. 

to summarise:  your not using a gin pole, who know how your guys are connected to the earth, your upper guys look to be attached too low on the mast, you look to be doing shotty concrete work, your winch looks to be sub par, and your tower pipe seems too small a diameter. 

so you've already had two failures, and there isn't even a machine on top yet? 

common steadfast, get your head on your shoulders!

adam

[tanner0441]

Hi

OK point taken if your as deep as wide then as long as your bolts are well into the concrete it should be sound. Why did you lower the mast along side the wall? If you lifted to the wall you could have fixed the winch to the shed and you would have less force to do the work, you would have been lifting the mast to start with then a horizontal pull to the vertical.

I want to see it work for you because some of the things you are doing are similar to what I did at the beginning. I made my first blade mount out of solid oak, strong I thought.  Wrong the first good wind we had it split with the grain, shedding my plastic pipe blades, I then made a 5ft twin blade out of a single piece of pine, stuck it on the end of a 24 V Amtek held on to it and pointed it into the wind, it spun up and while I was busy watching the volt meter the wind changed, all I will say is, it was a big bright flash, a lot of pain and a bruise on my forehead. I helped to put a ham radio mast up for a field day and while two mates pushed the mast up I put my foot on the base, as soon as they started pulling the guys the mast slipped smacked me on the ankle and sat me on the wet grass. So I am not criticizing you on a personal level but trying to help bu looking at the possibilities you will not have maybe seen yet. Your winch base is a prime example, remember no matter how big a piece of steel is there will be a point at which it will bend or break.

You will hear people on here talking about triangles, try to make your winch cable, your mast, and the ground make a triangle not a parallel line, and you will have few problems lifting your mast.

Good luck with your project, but on rainy days when you can't work outside spend an hour or so reading back though the old posts on here..

Brian.

[Steadfast]

Interesting winch ideas, brian
can you elaborate on them, so I can use them as fuel to brain storm?

I have at least 1 more week to think about what I am going to do with the winch stand...

I like what you said about triangles...
and it helped me come up with this idea:



This must be better than this mistake:


What do you guys think of it?

[tanner0441]

Hi

The none variable is the mast base, everything else is variable.  The point you attache  the cable to the mast, the placing of the winch.  With a 30ft pole like yours I would have thought could be pushed into position with a couple of mates on the pole and one on each guy.

If you are working light then use a gin pole fix it to the mast, fit a cable from the mast to the gin pole and the winch cable attaches to the gin pole at the same point.  At this point you are going to read how other people have done it, and the way the forces act on the cables to raise the mast, when to fit the guy wires to stop the mast going right over the vertical and landing on whoever is working the winch.  Even the placing of the guys so the winch cable provides a symmetrical load on the guys opposite it to stop the mast swinging.

Everything you need to know is on this site from the simple to the technical, someone on here has done it, encountered the problems and the fix. You have come in for a lot of criticism because what you are trying to do is basic but the way you are going about it at times is dangerous.

Again good luck with your project but if your offered advice take it, if you don't understand ask. Ignorance of your subject will illicit help and guidance. Arrogance will get you stamped on.

Brian

[tanner0441]

Hi

I still don't think you understand about triangle................  Picture you mast is laying on the ground, your gin pole is sticking up from just above the base hinge, the cable attaches to the mast at about 45degs. the winch cable runs from your winch up to the top of the gin pole. When the winch cable comes under tension it pulls the gin pole towards it, this in turn applies a lifting moment on the top of the mast causing it to rise as it pivots about the base hinge. If you have it right when the gin pole is close to the winch you should be able to attach the last of the guys and get the mast vertical.

There are masts on here over 100ft erected by this method.

Brian

[fabricator]

I cannot believe anybody would consider lifting a monopole without a gin pole, this shows how little you actually know about the physics involved in this project, I'd estimate the chances of catastrophic failure resulting in property damage and God forbid individuals are conservatively 90%. This is a Rube Glolberg set up that people who have been there and done that are trying to give you help with and you pretty much dismiss most of it, I'm outta here good luck you are gonna need it.

[Steadfast]

A gin pole.... hmmmmm.....
I did not know what that was either....until now....

I just saw some pictures and it makes perfect sense why I had such trouble.
huh....
But...then again....THAT is why I am here.... to learn about such things...

I can make one of those...  with a brace between the mast and gin too...
easy cheesy...

Thanks Brian...
your patience is appreciated.

[Steadfast]

Hey Fabs..... I hear ya man...
And, I know you mean well...
That's why you get so bent out of shape some times.

But I also gotta say...
You are definitely a "Son of thunder"...
And your last post was pretty funny too.
He he he....

[CraigM]

Just be safe Steadfast, you have a wife and family that want to see you in one piece.

And rip that god-awful tinker toy of a tower brace off your shed! 

[CraigM]

Speaking of sheds, you may have a difficult time locating guy wires with your shed being close to the tower. Most tilt up towers I've seen have 4 guy lines located 90 degrees from each other. Not sure how you'll arrange your gin pole and guy lines to avoid conflict with the shed. I'm sure the good souls of this forum can help steer you in the right direction.

CM

[ghurd]

I did what research I could understand (I can't remember what half the symbols even stand for).
Then I asked for help.

And I can tell you I would not put a 20 pound 4' dia machine on your initial design,
even if it would tilt up (which I doubt).

They are telling you stuff that is going to save you money and frustration.
G-

[Steadfast]

Look... the new foundation even came out sort of "festive"...



 

[Petie]

Try something like this for your winch:



Threaded rods go down 4 feet.  Criss-crossing them are a christmas-tree of re-bar at right-angles, held together with baling-wire.  The top is square because of the form I used at the top, however underneath the form didn't go all the way down.  I also believe in letting some ground moisture seep in and slowly cure the concrete.  I also "squirt" the top of the concrete pad while it sets, every few hours or so.

My tower base was a massive-overkill so I won't hold it up as an example.

I've been looking for a hand winch like yours, Sparweb.  I assume it has a brake?  Would you mind telling me where I can get one?

[tanner0441]

Oh dear!

I just noticed the pivot for your mast.  Please tell me you have a piece of tube up inside the first few feet of your mast, and a short piece running across the mast as a bearing.... If not that piddly little bolt you are pivoting about had better be high tensile, also the other hole through the mast to lock it in place has removed a lot of the structural strength of the tower.

If I were you as you live in the US I would make sure your medical insurance is up to date and if your in a rural area there is somewhere flat for the air ambulance to land.  Because until you appreciate the loadings on various parts of your set up you are likely to need it.  You jumped on people to point out it's a lightweight set up.  Take a can of Coke tie it to the end of a 6ft piece of lightweight tube and holding the tube at the other end hold the can of Coke out at arms length.

I can't believe you have done any research on what you intend to do, you have had what seemed like a good idea and went for it.  My mast is only 30 ft it is a lightweight setup the mast pivot is a piece of heavy duty tube welded into the bottom section across the mast the bolt that goes through it is high tensile and there are no other holes anywhere in the mast apart from two right at the top to lock the yaw stub in place, and the guy fixings are welded just below the blade sweep.  It is a cheap Chinese thing made for a price not to impress but it follows all the basic laws of physics and safe engineering practices.

I would like to see your guy anchors and the section of your guy wires, and how you attach the guys to the mast and anchors, and how you intend to tension them to make sure the mast is vertical.

The title of your post was wrong, re name it to a thousand and one ways to break you neck with a light weight wind turbine.  You do however impress with you enthusiasm and sticking power..

Brian.

[birdhouse]

a photo of my tower base.  gin pole exiting left of photo, and tower exiting top.  reinforced hole for wires.  just something to consider.  pipe over pipe hinges are very strong, and reliable! 

[tanner0441]

Hi

How it should be done. steadfast even though you complete system may way less than 100 pounds, if your winch can pull 500 pounds that is the force your mast could see acting on it, especially as your trying to do it without a gin pole.  Everytime you drill a hole in your mast you have weakened it, you have to counteract that in some way.

Brian

[Steadfast]

good advice:
I plan to add a 2nd brace near the second hole...
ummm... here see this picture:



My father in law and I, plan to knock this out this new addition to the project this Saturday...
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[Steadfast]

Oh dear!

I just noticed the pivot for your mast.  Please tell me you have a piece of tube up inside the first few feet of your mast, and a short piece running across the mast as a bearing.... If not that piddly little bolt you are pivoting about had better be high tensile, also the other hole through the mast to lock it in place has removed a lot of the structural strength of the tower.
Brian.

My Bolts are grade 8... 3/4 inches thick... 2.5 inches long

[birdhouse]

alright steadfast, you finally not looking like an idiot!   

good for you for finally enacting a gin pole! 

there are ways to use a gin pole without the elaborate linkages shown in your drawings.  google bergy towers, may give you some insight??

adam

[sean_ork]

My Bolts are grade 8... 3/4 inches thick... 2.5 inches long

this 2.5 inch long bolt that is your pivot point goes through the two thick plate angles you have sunk - and through your mast

what diameter is the mast tube ?

let's say there's 1/2 inch sticking out for the locking nut - a 1/4 inch for each plate that only leaves 1  1/2 inch for through the tube

am I missing something or is that a very skinny tube