mechanical control

[windspeed]

I would like to have a simple mechanical control for my 10 ft so I don't have to lower it so often , I get alot of storm force wind and I am not sure if leaving it shorted will always keep it safe ( has anyone had experience of a 10 ft starting up up from shorted )

it would be a easier to build a new turbine than convert to a brake disc system  

I could not find anything by search  

I was thinking of a system that would turn it out of the wind or lock the blades

would this basic system be of any use on a 20 to 30 ft tower

I considered having a magnetic disc with magnets stuck or fastened on in a layout that would enclose the  nuts on the front of the rotor the locking disc would be attached to a pole long enough to slide into place from the ground

The pole and attached disc would be left in place until the danger passes and then could be slid of by pullin down on the pole

I realise  changes in wind direction would cause the attached pole to swing around with the turbine but I think it might slide over the tower cables not sure how it would behave

I would like to hear your thoughts  

[Norm]

you don't have an automatic furling system in the

design of your windmill?

[oztules]

Have a look at this effort from Sodes. It is an emulation of the Southern Cross shut down furl system.

http://www.thebackshed.com/Windmill/FORUM1/forum_posts.asp?TID=1106&PN=9

The old Southern Cross  pumper uses the Piggott method as well as the shut down /slow down system depicted here.

.........oztules

[Flux]

With the exception of 2 babies that are in a very low wind site all my machines have had a manual shut down. I have always used schemes based on the idea that Oztules links to. It may well be based on the Southern Cross as I based my original ideas on the Lucas freelite and that in turn seems to be based on the original Freelite developed in Australia.

The idea is to turn the tail at right angles to generator axis so that it turns the prop at 90deg to the wind.

With machines with slip rings this is easy to do and Elektro, Bergey and others have used it as a back up.

If you drop the cables down the centre then it becomes much more complicated as the control wire gets tangled up with the electrical ones. It can still be done with everything running down the centre with a bit of ingenuity but I have usually adopted a sliding sleeve round the outside similar to Oz's drawing. Translating the vertical sleeve movement into a direction to turn the tail through 90 deg requires a tricky bit of mechanism and I have used a lot of ways over the years, all work but none are easy to build and I seriously doubt that you could adapt the ideas to an existing furling scheme. It is a case of building it in from the start. I think this may also be true for a brake, it needs to be thought out at the start.

In dry areas where things are not going to rust up you may be able to do the brake or even a tail turner with Bowden cables but I would never have such things near anything that has to run in our climate.

Shorting is effective if the alternator is powerful enough but I like to have a back up that will stop the thing in the event of an electrical failure.

Flux

[oztules]

Here is the second link to the pictures of the Southern Cross furling. The furl "cable" (wire in this case) runs up the outside of the tower to a pull down lever system ... outside the tower. This would give unfetted access to the wiring down through the middle, without tangles or interference.

The pictures in question are half way down the page of Dinges motor conversion story... (there was a reason for this from memory)

............oztules