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yahoo2
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Posted: 02 April 2018 at 10:01am | IP Logged Quote yahoo2

Yep Bruce,

the problem with building stuff with metal is there is only strength in compression and tension, any metal that is on the central axis contributes nothing to stability in the other plane.
That is why the stiff metal masts have a larger diameter and hollow centre (or triangular lattice), when they bend there is compression on one side and tension on the other.

I guess it is time for one of my matchstick man drawings again, the ones the search engines love so much.




Ignore the zig-zag cross bracing, it does very little structurally under tension, as long as there is a triangle at both ends and the outrigger braces are there it will be all good. It would be even better with two outriggers 90 degrees apart tied in a triangle at the outrigger points.

You can also see that the lift angles on the cables stay the same using a gin pole, it stops us pulling on the middle of the tower.
Anyway, something for you to ponder and mull over, I have "dropped" a few towers over 100ft without the correct gear, that last 20-30 feet is pretty scary, it usually ends with something damaged.

edit: Wow it looks much better on the interwebs! its no fusion360 but you get the idea.


Edited by yahoo2 on 02 April 2018 at 10:12am


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Posted: 02 April 2018 at 10:31am | IP Logged Quote brucedownunder2


Yes, the Jin pole method is certainly the preferred way to lift and lower.

In my case , I erected a strong guyed vertical pole which I will call the stationary gin pole ,it's guyed and permanent.

this then has pulley sheave blocks at the top and a couple metres down from the top.

My lifting wire ropes go through these permanent stationary blocks and are then terminated on the tower to be lifted.

So, in ordinary cases the gin pole moves from the ground up or from the vertical position to the ground.

in my case nothing moves ,just the tower.

I think less weight (the windgenerator+blades)would solve the problem ,

solution ,get rid of the lot and go solar.

Bruce

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Posted: 03 April 2018 at 8:30pm | IP Logged Quote fillm

Bruce,

Yahoo is correct an the method he has shown is the simplest and most cost effective way of raising turbine towers.

As I know a little about your tower from visits many years ago, and from that and the pictures I can fairly well say that its not capable of a 80kg turbine without major modification . The lighter F&P were no problem in the day but now you have trippled the weight and extended the tower top with the 89mm ID Pipe . It is made from 75mm x 6 x 3mtr angle as you gave me a few pieces back then, I can not remember the full details of your build method but the best config is as a 20mm overlap stitch welded to give a + formation which give stability but still not as good as 100mm to 125mm pipe.

Your lifting method is pulling on different radius points and if they are all 3 apear to be going back to the same winch drum. This will not work as different lengths will end up with the inner point getting ahead and the upper lagging a bending the tower as it appears now .

The lifting method needs to be changed to the conventional "Gin Pole " this then has the frt guys permanently attached and as shown in Yahoo's drawing is pulled from one point and the weight of the pole assists the lift to the point of over counter balance at the top .. Or you could reeve as a single wire through wire rope pulleys and it would then pull evenly but the weight still might cause tower
bending if the structure is flimsy with the 2kw on the end .





Also from your pictures you have raised the height of the tower with some 89mm pipe that looks to be just bolted in the first 1 - 2 mtr painted white and not moved the upper guy rope . This is most likelly also causing the upward bend in the under the guy point .

The Upper guy point needs to be as close to the top as possible to minimize the unsupported, if you change this and also run the 3" 89mm pipe past the upper guy point it will then support the leverage exerted onto the upper section between the intermediate and upper guy point.

brucedownunder2 wrote:

Yes, the Jin pole method is certainly the preferred way to lift and lower.

In my case , I erected a strong guyed vertical pole which I will call the stationary gin pole ,it's guyed and permanent.

this then has pulley sheave blocks at the top and a couple metres down from the top.

My lifting wire ropes go through these permanent stationary blocks and are then terminated on the tower to be lifted.

So, in ordinary cases the gin pole moves from the ground up or from the vertical position to the ground.

Bruce

I missed your call today but will catch up soon, there will be a solution.


Warpspeed wrote:


If I had to do this all by myself, I would also worry about getting it down again at some future date. As I am now almost seventy years old myself, I can really appreciate your situation.

I think I might investigate getting a driller to bore a sixty foot deep hole and fit a a steel liner. Then lower each section down the hole and bolt the next section on top of the first, and so on. Then finally fitting the wind machine on top (at ground level).

Then winch the whole thing up vertically slowly letting out the guy wires as it goes up. It could be lowered fairly quickly the same way for maintenance. If the whole thing is built vertical to start with, the bending problem is avoided altogether.


Tony

Why you would want to wast copious amounts of money to sink a 60' encased bore hole so his tower can be raised and lowered like a tower crane is beyond compression to put a probably under 2kw turbine on . If its a space thing then stand alone tilt towers are available for up to 1 - 10kw turbines.They are the best solution for easy accessibility and no guy ropes. But the ground prep and concrete would not be as much as your idea and you undo a ring of bolts and winch it over .
After looking at the cost most go back to the trusty guy tower and gin pole



Edited by fillm on 03 April 2018 at 8:34pm


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Posted: 05 April 2018 at 4:40pm | IP Logged Quote brucedownunder2


Thanks Phill,. Tried calling you back ,but we'll catch up soon.
Ilda is finally home and safe -drama has finished.

the Tower, thanks for the illistrated drawing , my set up ie very similar,except for the addition of one extras sheeve block .

This illistration works , but the friction in the intermediate placed sheeve blocks causes some difference in lifting forces. ( thats my guess ,anyhow)

I don,t have any problem with the winch ,it's heaps strong enough . The weight of the 2Kw Gennie is a factor ,indeed.

If I could just get the bending sorted out to some lesser degree,I think all would be OK , I reckon once it's up around 45 or more degrees it would behave itself ,up and down.. Ilda and I ,sometimes just myself , have raised and lowered this contraption many uneventfull times in the past -I carry a deadman up-down-stop control switch on a 60 metre lead around the paddock as we ,I, check all safety aspects while in operation . works perfectly .

So, thanks again all of you for this discussion , Ilda is safely home at last after a very stressfull visit to her 102 year old Mum . Mums fine,.

Bruce

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Posted: 06 April 2018 at 2:36pm | IP Logged Quote SparWeb

How close to the swing of the blades is this top guy wire attached?
The photo you posted the other day makes it seem like there's at least a meter between the tip of the blade and the highest guy. Moving that up would make a big difference.

The change in paint colour from white to green makes me think there's a joint there, too. If so that will contribute to the bending. Getting the guy wire attachment above all of the tube joints will also reduce the bending.

The look of it though... it's still a heavy turbine for 100mm square tube. I'm not comfortable looking at that, like you are.

I am also no fan of Exmorks, especially the 2KW model. I saw the aftermath of one that blew up - in a wind speed it should have survived.

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Posted: 06 April 2018 at 7:57pm | IP Logged Quote fillm

SparWeb wrote:
How close to the swing of the blades is this top guy wire attached?
The photo you posted the other day makes it seem like there's at least a meter between the tip of the blade and the highest guy. Moving that up would make a big difference.

The change in paint colour from white to green makes me think there's a joint there, too. If so that will contribute to the bending. Getting the guy wire attachment above all of the tube joints will also reduce the bending.

The look of it though... it's still a heavy turbine for 100mm square tube. I'm not comfortable looking at that, like you are.

I am also no fan of Exmorks, especially the 2KW model. I saw the aftermath of one that blew up - in a wind speed it should have survived.


Those are all valid points that I did also point to as well. Apart from that I take it the "Blew Up" is a fairly explicit description, would it mean the fibreglass blades delaminated as many do and may have bought the tower down? In general these type of 1 ~ 2.5 kw turbines are of very robust construction except for the blades and easily outlast much more expensive overpriced but now bankrupt manufacturers. .

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Posted: 07 April 2018 at 8:37am | IP Logged Quote Warpspeed

Quote:
Tony

Why you would want to wast copious amounts of money to sink a 60' encased bore hole so his tower can be raised and lowered like a tower crane is beyond compression to put a probably under 2kw turbine on . If its a space thing then stand alone tilt towers are available for up to 1 - 10kw turbines.They are the best solution for easy accessibility and no guy ropes. But the ground prep and concrete would not be as much as your idea

What you say is all very true.
Any robust/reliable/safe method is not going to be cheap anyway, if everything is bought brand new and then professionally installed.

But some of us can get lucky sometimes, or have access to materials or services (mates in the trade) that most other people do not.

I do not know of anyone that has actually dug a deep bore hole to raise a fully assembled mast, it was put forward only as a theoretical suggestion, of being one possible solution to get right around the whole bending and high weight problem.
It would also be a very safe way to do it.



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Posted: 07 April 2018 at 9:54am | IP Logged Quote brucedownunder2


ok, thanks for all the feedback , might have to go back to a lighter wind-gennie.

worked perfectly with the F&P lightweight gennie...

Bruce

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Posted: 07 April 2018 at 1:58pm | IP Logged Quote flc1

you at a new place Bruce? good view in the pics
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Posted: 07 April 2018 at 4:49pm | IP Logged Quote brucedownunder2


Hi FLc1, still at Mt.Tamborine Gold Coast hinterland. Looked down last Wednesday on Carrara stadium for the opening of the Commonwealth Games .very nice place up here ,sort of compensates for my tower stuff-up's,lol.

My tower building has been a bit of a disarster, ol boofhead here,just can,t get it right !! . But, I'll soldier on with help from all you lurkers ,it seems the weight of the Exmork is just too much .

back to a lighter wind gennie,

Thanks all

Bruce

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Posted: 07 April 2018 at 8:46pm | IP Logged Quote yahoo2




larger diameter version of this would be perfect.

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Posted: 08 April 2018 at 7:02am | IP Logged Quote Clockmanfr

Here's my No1 3.7m diameter Hugh Piggott design down last winter for service its been up 9 years now.

You can see that my top gin pole wire that is taught is the main brace wire and is fixed as close as possible to the Turbine head but still give clearance for the blades.

The mast is 13 meters long made from 100mm dia, galvanised steel tube and butt welded at each 6 meter length and the 1 meter top section. Those butt welds also have 10mm x 75mm wide steel plate sections also welded on to spread the load on the joint, (Hughs method) I also drill 14mm holes for shackle connections.




The base mounting procedure, with the 6 meter long Gin Pole attached, its a scaffolding pole.







NOTE .... In this photo on the left near the wall, are 3 off those Chinese manufactured so called Wind Turbine mast units are absolutely JUNK and the welds around the bolt flanges were declared unsafe and shipments were scrapped. I got a few for scrap money and I cut them up and use them as gate posts around the farm fields.


The mast base is made up of 75mm x 75mm 8mm thick angle steel that wraps around the pole a good 300mm but I cut the bottom so I can fix a permanent 20mm diameter swivel bolt to the concrete mounted base plate angles.









Like you once down I use a builders trestle to take the weight of everything.

Trust this helps.


Edited by Clockmanfr on 08 April 2018 at 7:09am
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