Small wind turbine: mast question

[plasmanu]

The base has 2 holes.
The cement will be reinforced concrete and will leave the 2 axes as large as the thumb.
Cement poured on the metallic structure which will come out at high speed.
2 apricot-cut bolts with roudelles that go well: 2 large lag screws.
With 1 or 2 bags of cement is enough to make solid.
And the river is full of pebbles in basalt that I struggle to move.

The weight of the turbine is insignificant given the gigantism of the mast.
With 8 shrouds on 2 levels: it will have good distribution of the thrust.
It is the same turbine (mobile tail option in +) as the grandpa with his fence wires not stretched on the greenhouse of the vegetable patch.
Turbine about 25kg diameter 1,5m.

[Ruthenian]

Don't play sorcerer's apprentices! You have to calculate it properly.

Small evaluation with a pifometer:

We should first know the weight of the wind turbine, turbine included (without the mast)!

If you plant this in a concrete base, then you will have roughly these constraints in this calculation of "moment":
http://fr.wikipedia.org/wiki/Moment_d%2 ... canique%29

([Eval. maximum wind force *] + [lever arm of 3m or 165kg] + [wt. turb. & wind turbine]) x3 = "m"
([Eval. maximum wind force *] + [lever arm of 4m or 220kg] + [wt. turb. & wind turbine]) x4 = "m"
([Eval. maximum wind force *] + [lever arm of 5m or 275kg] + [wt. turb. & wind turbine]) x5 = "m"
([Eval. maximum wind force *] + [lever arm of 6m or 330kg] + [wt. turb. & wind turbine]) x6 = "m"
([Eval. maximum wind force *] + [lever arm of 7m or 385kg] + [wt. turb. & wind turbine]) x7 = "m"

* Maximum wind force, to which a safety load must be added which can never be exceeded!

Will the section of your mast tube support this?

In any case, if you put it in concrete, you will need irons waiting in the first section of tube and pour a little concrete there right? If you haven't thought about that, you could possibly add a 50cm section with the irons trapped inside, there you will have maximum rigidity at the base, where all the efforts will be concentrated.

But it is without guarantee, it should be seen all on the spot, it's just to give an idea ...!

You can explain your formula, I don't understand everything.

Can you explain for example:
Mat: 60 kgs.
Turbine: 30 kgs.
Blade sweep diameter: 1.7 meters
Mast height: 10 meters

Force on axis of rotation at the foot with wind and without wind?

[Obamot]

Not understand the correlation you make in your figures. Too complicated.

I did an empirical approach to calculating the "moment". Whose simplified formula is:

Force (X) lever arm.

In other words the Strength broken down into the load representing the complete turbine plus the weight of the mast and the pressure exerted by the wind at its climax, cumulated and focused at the height of the turbine, all multiplied by the distance from the anchor point (which is the ground and constitutes the lever arm):
http://fr.wikipedia.org/wiki/Moment_d%2 ... canique%29

It was just to make people understand, in reality in the case of mat, it's more complicated:
http://fr.wikipedia.org/wiki/Moment_d%27inertie
http://fr.wikipedia.org/wiki/Moments_a% ... dynamiques

So much for the basic overview of the approach.

[Obamot]

PS: I had put several values, not knowing the distance between the anchor and the trubine, because the mast is a certain weight, and it had to be taken into account ... (then Plasmanu is big enough to know what that should be done.)

[plasmanu]

With a pifometer.
It will have to double the values.
For a set of 500kgs you need cables of one ton: to ensure a minimum of security.

[Obamot]

Doubling according to what goal, it is to be seen ... But double what?

Too few! You might take it in the g ... one day

to ensure a minimum of security.

... uh ... who talks about "minimum" while looking for zero risk!

I will gently contradict you, since you are possibly waiting for opinions!

Mat of 385 kg + turbine / propeller 50 kg + force exerted by the wind ~ 550kg (for 1 m2, and it's just for a "gale" according to the Beaufort scale ...)
Total 985 kg ... you are already a ton there (with the pifometer, without safety margin ... it's light, if you know the force that can exert a lever arm ......... ....................................)

Calculation of the moment: 985 Kg x10 = 10 tonnes, without safety margin (if you don't want to lower the wind turbine with each gust of wind, and who will do it when you are not there ... on vacation ...)

On the other hand, it would be necessary to calculate how much holds your base, everything is there .... So it must be put into perspective, but probably not as much as you did. How much would your mat hold in bending force? 15 to 20 tonnes? It is quite possible that it will hold, however .... this is the first question to ask yourself amha ... Find out in writing, where you bought it.

[plasmanu]

8 cables of one ton of hold seem correct for a 500kgs mast.
The thickness of the mast gives it a very high solidity: hard to encrypt.

My problem in fact is the ball that will turn the mast when it is lifted: there is no. It is a model to be fixed like a lifting crane.

[Obamot]

Eight? Are you sure ?

[plasmanu]

Halfway up there is the first set of guy lines: 4 hooks.
At 4/5 of the height the second set of 4 hooks.
4 + 4 = 8.

[Ruthenian]

look at what we could do in a simpler way of course:

http://www.youtube.com/watch%3Fv%3D6dpL ... Igu6vRsVsQ