Cable wind up?

[g6anz]

Hi guys, I just joined this board. There is some excellent stuff here. I thinking about building a small turbine  as an exercise in engineering with a practical result. There is one thing that I cant get my head around. With a horizontal generator driven by a standard propellor and a tail how do you stop the power cables from twisting up as the assembly rotates to follow the wind? The only way I can think of is using slip rings with all their inherent troubles. Am I missing something?

Malcolm

Pretty well documented here why slip rings are not really needed already. Moved to newbies.

[Flux]

Only on exceptional sites is there a problem. In most places the wind only does a complete rotation a few times a year, With a hanging vertical cable it will stand many turns without problem and every few months you can just unwind it.

In more troublesome areas some people fit a plug and socket at the bottom and just unwind it on a calm day.

There are a few very turbulent sites where this can happen often enough to be a nuisance but few and far between.

Slip rings can be satisfactory, but if not built to the highest standards they usually give trouble.

Flux

[veewee77]

What you will find, as others here will tell you (did you google search the board for "cable twist"?) is that over the course of time, it pretty much evens out. Many have had theirs up for over a year with only one or two twists in it. Generally, the wind does not go in a 360 degree thing over time, but generally fluctuates only about 180 degrees with very few exceptions. Many locations even only see about a 90 degree fluctuation, especially coastal areas, over time.

Since it is a good idea to bring the windmill down at least once per year anyway for maintenance, if it does get twisted, just untwist it then.

The other solution is to put a hefty twist-lock plug and socket at the bottom of the tower so it can be unplugged, untwisted, and replugged again if that twist or two bothers you.

Google search the board for cable twist and you will see included are the following plus many more. . .

www.fieldlines.com/story/2005/2/1/42930/30269

www.fieldlines.com/story/2004/9/2/22724/72530

www.fieldlines.com/story/2003/12/22/181518/95

So, just google search for "cable twist" on the link on the Fieldlines page and it will tell you you don't really need to bother with it. . .

Doug

[veewee77]

oops. . . did the links wrong. . .

Story 1

Story 2

Story 3

[mitcamp]

g6anz Check out my slipring pictures in my user files.  I have been using these for years and I,ve never had a failure. knock on wood  They must be covered to keep out the weather. I,m not sure how to put a link in here for the sliprings, but if you have trouble finding them I will dig them out somehow.  Mitcamp

[wpowokal]

There is an exception, if you have a site with tree/s or buildings that cause turbulance this can cause wind up of your drop cable.

allan down under

[g6anz]

Many thanks guys. I'll just leave a large loop of cable so it can twist up. One less thing to worry about!. The engineering on the sliprings looks great...way beyond my cababilities.

I'll let you know how things grow,although this may take some time

Malcolm

[Capt Slog]

Yup, that's what happens to me.  Also, if the pole that the turbine is on is not very high, it does take many twists to get to uncomfortably tight.  I first put up mine with the thought of "two twists per year" and found three in there the next morning.

I now have slip rings.  I notice in the above post by Mitcamp that he mentions keeping out the weather.  Mine are open to the elements at the moment, perhaps that's something I will have to change.

[jmk]

 Mine winds one revolution clockwise with every low pressure system. It takes about one to two weeks to wind around 360 deg. I like to twist it up counter clockwise once a year and its no problem.