My 10 footer stopped then ran then stopped?? Heres Why.

[TomW]

The past few days it has been very windy here. YAY!

Been pulling in great power from the 10 foot 24 volt DanBilt. Lots of turbulence typical of wind from the Easterly directions.


3 days ago I noticed it was not turning and it was quite windy. Well I am super busy getting my wife back on track after a total hip replacement Monday so it was just a anecdotal at the time. Something to look into when I had some time or someone could be at the house while I was up there.  It would be turning sometimes cranking power then it would be stopped when it should have been running.

Took some pictures from the ground and by zooming in on those I could see the magnet rotors were tight at the top. I could see a missing stator mount nut also.

Last night I had time to lower the tower so I started that. Usually a 15 minute job. Unless the winch fails. It did. No damage but a tower hung up with the turbine about 20 feet up. Can't go up can't go down. Daylight is failing fast.  I grab an extension ladder and jammed it under it to hold some of the load. backed the Dakota under it put the stepladder in the bed and wrenched off the prop and tail. I use a through bolt on my tail hinge so it cannot lift off. At least now if it falls the prop will survive.

Today I got a couple chances to get it fully lowered. I worked the ladder up under it with a 2X6  until I had enough slack to transfer the cable to a chain so I could lower it with the truck. That went easy.

Pulled the head off and took it in and clamped it in the vice. pulled the front magnet rotor off. Discovered the back nuts on the outer magnet rotor had loosened on one side. So things were slack enough that the rotors tipped enough together to clamp the stator.

Only damge is a lightly scuffed stator which appears fine. No bare copper:




I have some photos of it in the air but was so frazzled by the time I got it lowered I didn't take photos of the head before pulling the front rotor and stator.

Magnets seemed fine just buffed.

I must live right. This will be fixed and running by fall for sure  

Curious enough, the prop was treated with polyurethane about 9 months ago and it looked as good as the day I bolted it on. No cracking peeling or degradation from weather.

Photos of the thing in the air before I lowered it are over here:

http://pics.ww.com/v/TomW/FarmStuff/April2010/4-16-2010/

Tom

[Volvo farmer]

Lucky!

Say, is that the old school 10' design with the 1"x2" magnets and the polyester stator like I had, or is the newer design?

[dlenox]

Tom,

Good luck with the hip replacement, I know others that had it and it turned their whole life around!

Dan Lenox

[TomW]

Lucky!

Say, is that the old school 10' design with the 1"x2" magnets and the polyester stator like I had, or is the newer design?

VF;

It is an ancient Unit with round magnets. I got it from DanB long long ago like 6 or maybe 8 years ago? I forget exactly. It has been a rather unreliable machine for me. Has killed 3 props. Dan fixed that last time he stopped by (delivering my 12 footer).

It has a stator that is newer than the rest but unsure of the method or materials used. Maybe Dan will chime in with an answer. He or his guys made it. And I do not know how to tell by looking

Once I get the 12 footer installed this one will be for backup or maybe direct water heating but right now I could use the power.  Oh well it ran well for about 9 months unattended this time so no big deal just more stuff to do at a time when I got no time for it.

Was sitting here early AM Sunday back from morning chores listening to Led Zeppelin IV and writing this actually got motivated to go snag a couple photos of the Magnet rotor laying on the tailgate of the Dakota. Too dark yet in the back of the shop to get one of the rear rotor tho.



[p]



Massive photos I would get shot over posting here can be found over on:

http://pics.ww.com/v/TomW/FarmStuff/April2010/4-16-2010/?g2_page=2

Automatically resizes photos for use here check out pics.ww.com A nice free hosting location for photos run by a long time member here JacquesM

Tom

[TomW]

Tom,

Good luck with the hip replacement, I know others that had it and it turned their whole life around!

Dan Lenox

Dan;

Thanks. Really. Hers was so bad by the time she got in for the surgery that she actually gets around better now 6 days after surgery than the day she went in. First day home was kinda scary for me because she was pretty helpless getting up and unsteady probably due to the high grade pain medications . That all went away quick. She will be planting her garden soon I think. A bit late but should be good to go.

There is no doubt this will be a big difference for her and myself by extension.

Thanks for the encouragement.

Tom

[wooferhound]

You Know . . .
The nuts coming loose on wind turbines is starting to be a common failure.

[bj]

   Glad Amy is doing O.K. Tom.
   As Woof said loosening nuts seems like a more common problem now.  I have had some problems with it
on engines that are highly stressed, and it only seems to occur on fasteners that are in the same plane as the
rotating assembly.  I hate Loctite if I am the one that has to remove the fastener, but it seems to work for me.
   At least the failure wasn't ugly.

bj Lamont AB Can.

[DamonHD]

You Know . . .
The nuts coming loose on wind turbines is starting to be a common failure.

The nuts who *work* on turbines are the ones that I worry about.

Meanwhile I already have dodgy hips and my dad and his sister and brother have had most of theirs replaced at least once.  Doesn't make my turbines work...  (Nor my solar PV as it happens.)

This co-relation science stuff is useless.  %-P

Rgds

Damon

[Volvo farmer]

Was sitting here early AM Sunday back from morning chores listening to Led Zeppelin IV

Oh, Major faux pas there Tom. Only "Houses of the Holy" should be played on Sunday.  And Side 2 should always be played first, so that "Dancing Days" is the first song 

[TomW]

Oh, Major faux pas there Tom. Only "Houses of the Holy" should be played on Sunday.  And Side 2 should always be played first, so that "Dancing Days" is the first song 

VF;

In light of the last week or so, When the Levee Breaks seemed most appropriate.

Now I am going to have to either split off this thread or stuff it in Diaries so the personal stuff is topically located

Tom

[Tinbendr]

The nuts coming loose on wind turbines is starting to be a common failure.

I'm sure the builders know there are many different ways to secure the nut.

Use fiberlock nuts.  The only drawback is that it's a pain to start the nut backward on the thread-all.

Use a castellated nut.  The drawback here is you weaken the rod by drilling a hole for the cotter pin.

You could just drill a cotter pin hole behind the plain nut, but again you're weakening the rod a bit.

[TomW]

I'm sure the builders know there are many different ways to secure the nut.

Use fiberlock nuts.  The only drawback is that it's a pain to start the nut backward on the thread-all.

Use a castellated nut.  The drawback here is you weaken the rod by drilling a hole for the cotter pin.

You could just drill a cotter pin hole behind the plain nut, but again you're weakening the rod a bit.

Well, I had put a dab of Gorilla Glue [tm] on the back of the nut and threads of the ready rod but it was not adhered to the probably oily threads of either. It is there but not stuck. Another bright idea that failed

Probably use stud and bearing mount Locktite this time after thorough cleaning of parts.

Iron mongery is just not my thing.

Tom

[ruddycrazy]

G'day Tom,
                It wouldn't hurt to use double nuts and the super strength loctite, that way they will never come loose on their own. I'm sure you know how to double lock a nut but I'll throw in my 2.2 cents on the subject.

Don't use loctite on the inner nut, just get the required tension with it and do it all around the stator. Then wind the second nut down and prime the thread with loctite primer then put some loctite on and use a spanner on the inner nut to ensure you don't over tension the inner nut. Lock the 2 nuts together so they are tight but not stretching the all thread. when it's time to undo the nut simply apply heat to the outer nut and have 2 spanners handy. Loctite will unstick around 100C.

Cheers Bryan

[TomW]

On further inspection in good daylight I see at least one crack through a mounting hole and 1/3 or so across the face. All 3 holes have at least the beginning of a crack from the hole edge to the outside of the disk.

So much for getting it back up quick

I have another stator on an unused turbine head but I just cannot remember if it is 12 or 24 volt.Guess I get to take it apart and see. Too bad neither of these are built with jacking screws and it takes a morphodite bent wrench to get in to pull the rotors apart which kills any adjustments you made previously.

Anyway just an update on the true damage. Not sure what it is cast of but it seems brittle with small hunks gone in some of the holes.

Well on to the investigation. If the sun gets out again bright I will get a photo with strong light behind to show up any cracking. Kind of poor mans Magnafluxing.

Tom

[TomW]

For anyone interested the light through the stator idea no workie.

Stator is simply too opaque.

Here are a couple links to large photos of the stator that show the cracks. They do not show in a legal photo here.

A crack marked with a marker at about 1 0'clock and and at about 5 o'clock is a surface chip of fair size:

http://pics.ww.com/v/TomW/FarmStuff/April2010/4-16-2010/100_2252.JPG.html?g2_imageViewsIndex=1

At about 7 o'clock is the crack from the other side, complete with a surface chip and another chip at about 10 o'clock.

http://pics.ww.com/v/TomW/FarmStuff/April2010/4-16-2010/100_2253.JPG.html?g2_imageViewsIndex=1

I don't think I would trust this as is for a minute and not sure it can or should be repaired? I don't even know what material it is to attempt to select an adhesive.

Still pondering the options.  At $275 for a replacement it might have to go back in line til I get the 12 footer up. After that it doesn't matter except for backup or alternate use so spending anything on it is likely short sighted right now. Best wind of the year here is now and of course the turbine is down.

Any ideas on a fix? the crack does not run through a coil.

Tom

[kurt]

if it were me i would just get some stainless steel sheet metal reasonably thick stuff and make a rectangular patch on each side for that cracked mounting hole held on with a couple small bolts through the stator there is plenty of meat there that does not have coils in it looks like just make sure the stainless patch material stays outside the path of the magnets. sorta like this (parden crude drawing) http://pics.ww.com/v/kurt/junk/tomsstator.jpg.html?g2_imageViewsIndex=1

[12AX7]

Hello

First of all,  I have never built nor played with a axial alternator. 
With that said, I do have a comment and a question relating to your problem.

First the question,  why can't you rotate the stator several/ thirty degrees and drill new mounting holes, and plug the old ones?

And then the comments,   First,  the stainless hardware.  I worked in the food/packaging industry for 25 years where stainless was just about the only hardware used.   NO ONE liked working with it.  Frequently it would 'gall' or strip.   Nuts and bolts coming loose was an everyday event.  A common opinion was that the stainless bolts would "stretch".   This (the common opinion) would explain why the nuts/bolts would strip, gall and loosen.  Using the right loctite for the correct application was always pushed.  Before applying the loctite clean the hardware of all oils/contaminants.
Also nylock nuts (and lock washers) had a ONE time use to them,  use them once, then toss them out.

It was already suggested in another thread (don't recall where or when)  the idea of putting in a bushing in the stator mounting hole, so that the nuts would run tight against the bushing and not the "soft" epoxy.  I'd like to suggest that this idea be "kicked around" by those of you building and flying these DIY alternators.   I can't imagine that one can tighten nuts/washers enough with out causing damage to the epoxy castings.  In these applications, I would think "double" jam nuts would be a must.

In my days of playing with TV/Radio antennas stainless hardware was GREAT,  until it loosen and things started turning on their own,  or worse.   Here in WI (back in the good old days) there was a relationship between how steep a roof was to how quickly the antennas would fail.

Good luck!

ax7
Mark

[Tinbendr]

Any ideas on a fix? the crack does not run through a coil.

When we fixed similar fiberglass items, we would carve a V along the length of the crack and  carve out a valley for a new strip of cloth.  Not a quick fix, but usually successful.

[kurt]

rotating the stator to another position and drilling new mounting holes is an interesting idea much simpler and easier than my idea. 

[ruddycrazy]

G'day Tom,
                There doesn't look like much clearance between the holes and the magnet rotors so my 2.2 cents worth would be drill all holes out and use a dremmel tool to gouge a depth to epoxy in

A. a steel pipe then weld the pipe ends onto some thin plate the epoxy the lot together and keep the original level or

B. Do the same dremmel job and epoxy the hole up and drill new holes but by doing this trying to brake might cause the new holes to crack.

With my first dual axial flux genny I'm thinking of putting in a solid disk above the coils for mounting with fingers Tig-welded on towards the coils but not in far enough to do damage to the flux. So the resin will hold the whole stator bracket secure as with the 50x15 N52's neos i'll be using I reckon trying to brake in a storm will put a heap of pressure on the stator.

Cheers Bryan

[Dixie]

Hi Tom - I think the stator looks fine...
I suppose if you're concerned, you could sand it a bit around the holes, and maybe epoxy some fiberglass cloth around the offending crack/hole and redrill through that, that should make it very strong.

There is fiberglass cloth there though and I don't think the cracks will cause a problem (I've seen worse and not worried about it).

[Dixie]

Oh, and just so you know... even though I'm a dog, named Dixie... I did consult with DanB and MattB before posting so my opinion is based on stuff they told me.

[Devo2]

Hey Tom,I find I have a lot better luck with the down time if I listen to AC/DC over Led Z. My wife wants me to put it on the tail(guess I listen to it to much-lol). 

  I have had cracks before & had decent luck with a tiny grind with a dremel & a little Bondo. Drilling new holes is also good if you have the template around to keep the coils centered.  When I tighten mine I use a rubber washer like a garden hose has Under 2 flat washers & then I line up the stator with 2 nuts so it doesn't scrub,put a fair amount of tension on them & then I lock them hard with a jam nut on both sides. So far so good. I think on my next one I will use a bushing as stated earlier, sounds like a great Idea to take some stress off the stator.
 
  What kind of power do you get? I always wanted to try rotors as I have a few around.


Devo

[TomW]

 
  What kind of power do you get? I always wanted to try rotors as I have a few around.

Devo

The Doc Wattson says it has done 75 amps into a 24 volt bank. No clue fr how long or exact battery volts though. That s pretty much 2 KW give or take.

Tom