Manual furling for 13 foot turbine

[bigrockcandymountain]

My turbine is up and running with new blades, a tilt to the generator for tower clearance, and a shut down mechanism. 

It is just a hand lever at the base and cable up to a swivel, and more cable to the tail to pull it in.  Hopefully it does the job. 

[bigrockcandymountain]

One more picture.

[SparWeb]

You couldn't have picked a better day to test it.  All iced up like that is just the kind of stuff that might cause it to jam, and at the same time just the kind of bad weather you will need it to work someday.

[kitestrings]

The cable all looks to be pretty heavy-duty, which may be good.  Is there enough slack, or freedom of movement such that the cable does not in any way restrict the normal motion of the furling?  This would be my only concern.

We had a 12' Scensenbaugh that we operated for many, many years.  It had a relatively light-weight flexible steel cable for manual furling.  We always had continual problems, however, with 1) the weight of the cable (down a 100' tower) affecting the furling and 2) the lubrication of the cable through a short section of armor-cable that served to transition the line of pull from vertical to horizontal (around the generator body).  On our axial we went to dyneema wire-rope based on a recommendation from ClockmanFRA or midwoud1 IIRC.  This has worked much better for us.  In is light weight and incredibly strong - 4 mm has a working range of about 1,200# - it doesn't stretch or absorb water.

Looking good.

[bigrockcandymountain]

Kitestrings you are right it is very stiff.  I am not sure if the pictures show it clearly but the blue bar is independent of the tail so when it furls the cable stays straight.  That way it doesn't interfere with normal furling. 

I would like to eventually put a 12v actuator in place of the lever at the bottom.  I didn't bury extra wires,  so a wireless remote and small battery and solar panel will have to do. 

[kitestrings]

Ahh, I think I follow it now... so the blue bar pulls the tail closed if you manually furl, but the hinge can still operate if it is in the running position and the blue bar stays put.  Am I understanding that the cable is fixed at both ends and the steel piece with the "ears" (looks like two holes on opposite sides) moves on the outside of the tube, down to furl manually.  I had to stare at this awhile and I'm still not sure I've got it.  ~ks

[bigrockcandymountain]

I think youve got it.  The piece with the ears is the swivel.  It slides up and down but doesn't turn, while the small bracket inside the ear piece, that the cable attaches to turns with the head.  It seems to work so far.  I shut it down this morning just to try.  The rotor actually came to a complete stop.  It wasn't super windy though. 

We made 4.5kwh last night in fairly light winds. The classic is working good, but there are a lot of what ifs that leave the turbine freewheeling.  I think i will add a clipper type device on the 3 phase ac side. 

[kitestrings]

It looks great and certainly that's good production.  Have you noticed much difference between the old blades and the new?  I noticed the newer blades seemed to have a bit thicker cord, but the photo may have been before you completely finished them down.

We used a small hand-winch at the base of our tower for quite awhile.  It worked perfectly fine, and no question where it is positioned.  The downside is that sometimes when you want to shut it down its freezing, the wind is screaming and it's snowing side-ways.

I've gained quite a bit of confidence with the actuator control that we're using now.  I can pretty much shut it down fom the house in any sort of wind.  I often shut ours down when I turn in for the night if it is really rough conditions.  Sleep better that way.  I also have it set to trigger thru the Classic, Aux1, on PV V on High.  It is set for about 126V, with very short delay.  This is higher, but not alot above the clipper set-point (~115V IIRC).  As soon as the controller starts to unload the turbine, the voltage will climb very rapidly.  If it persists, the thing will shut-down on its own - it did it just a few days ago if strong sustained, high-gust conditions.  I have the reset voltage set quite low, like 35V, so it in effect prompts a manual reset unless conditions really fall off (and PV is also not pushing the voltage up).

Good luck and keep us posted on progress.

[Jason Wilkinson]

Does the cable run inside or outside the tower ?  If outside ,what happens when the turbine turns 360 degrees, your cable wraps around the tower, if inside , it comes out  on top of the  entire assembly  through a seperate  outlet than the three cables, onto a pully that way avoiding wrapping around the tower .  Male sure you've got good isolation from the power cables
 Jason

[bigrockcandymountain]

It runs inside the main tower pipe.  The top 4' of tower is way smaller diameter and it runs outside that.  The swivel is on the outside of this pipe.  The head is free to turn all it wants and only the power cord twists.  The cable in no way interferes. 

The cable is 10awg 3 conductor soow so very flexible. 

[bigrockcandymountain]

I thought i would post an update on this.

I have had the turbine manually furled for a couple months now.  I just don't need the power this time of year.  The furling works perfectly.  I had it down for greasing and all looks good.  It doesn't turn a blade no matter how gusty and awful the wind gets.  I don't have the wires shorted or anything either just the tail furled. 

[kitestrings]

Good to hear, and I had wondered how things were going with your turbine.

We do the same thing.  In the summer - pretty much now thru maybe Sept - we only sporadically run the turbine.  The winds drop off sharply anyway, but the PV provides about 10-15 kWh a day, and this is ample for our needs.

~ks

[bigrockcandymountain]

I'm having trouble posting pictures.  They are on this thread so have a look and ask questions if you like. 

As kitestrings suggests, my furling method suffers from being too heavy.  All that weight pulls on the tail continually, and as it furls and unfurls, wears everything too.  I will fix that by making a magnet catch so the blue furling arm stays put unless the manual lever is pulled.  The magnet will have to be powerfull enough to hold up the weight of the cable and swivel.  It will be out on that blue lever, so i can give it a leverage advantage.

It should work, but i don't have a portable welder right now so it will have to wait.

Kitestrings method with dyneema line has a lot of advantages. I was not sure about the power cable and furling line twisting up inside my tower tube.  Kitestrings tower structure is open so it works great for him.  I'm sure it would be ok in a tube tower though too. 

[SparWeb]

Thanks for giving this thread a bump.  I was looking for stuff like that.

[bigrockcandymountain]

My turbine is lowered for maintenance and to install the new rotor.  The furling guide pulleys have been wearing for about 4 years now, the last 2 years with no grease.  It was still working  but very worn. I finally got some proper oil impregnated bronze bushings for in the pulleys, so hopefully they last longer this time.  It was a good excuse to practice hitting a press fit on the lathe.

[SparWeb]

I like the grease fitting added to the bold. I ought to try that myself...

Lathe skills like hitting a target dimension in a tight tolerance fade without practice.  Did you use the lathe in your other photo from today?  It's not up on legs so now I'm wondering if you have another lathe...

[bigrockcandymountain]

Ya, that's the lathe.  The picture makes it look pretty small, but it stands a comfortable working height just sitting on the floor. 

The bolt was hard to drill.  It was mostly soft, but with some very hard spots that liked to eat my cheap mastercraft bits. 

[kitestrings]

That seems like a good upgrade.  My understanding is that oilite makes a good choice for where there is low speed, but high loading between the moving parts - like this application, I assume.  Did I read, or hear, that soaking them in oil is a good thing before install?  We used graphite impregnated bronze on our tail hinge.  It seems to work well; has held up well to date.

I'll be anxious to hear how the new blades sound, look, perform.  Keep us posted on any perceived change.  Best ~ks

[SparWeb]

The picture makes it look pretty small

Aha, dwarfed by those huge blades!

About machining hardware - I've heard that a lot.  That thing in your picture could be some kind of stainless.  If you don't keep the drill feeding, the metal can work-harden in a second and then it takes a huge effort to push the drill further.  Which makes the decision to withdraw the bit to add coolant kinda complicated.