Wind Turbine Transmission

[ChrisOlson]

with #2 diesel fuel in it for a lubricant.
Just don't forget the Motorkote.  But then, you new that

That's what I need alright - a Cetane Number of 47 for chain lube  
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Chris

[ghurd]

Hey Chris,
Are you comfortable with the shaft dimentions?
Just looks kind of long and skinny from here.
G-

[ChrisOlson]

Are you comfortable with the shaft dimentions?

Really comfortable.  Looks can be deceiving.  Take a look at the rear axle on your 1/2 ton pickup sometime.  That input shaft and front main bearing in this turbine has about 20% more load carrying capability than a Dana 44 rear axle.

What people should really be concerned about is using little #42 spindles with a 15123 outer bearing, and hanging a wind turbine on it.  In an automotive application the inner bearing carries the load and the outer bearing is a pilot to keep stuff in alignment.  People are hanging 17 foot blades and whatnot on those little 15123 bearings with only a 1.25" journal on the end of the spindle - not even a good design from the word "go".
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Chris

[keithturtle]

I've had real good results with the hyper-lubricant on many different metal-to-metal applications other than crankcase oil.

I wasn't referring to the fuel additive; motorkote mixed in with diesel fuel makes for an excellent light-bodied lube, in my experience.   Looking for any advantage to extend service life, I thought it might help.   I may be wrong

Turtle

[ChrisOlson]

I wasn't referring to the fuel additive; motorkote mixed in with diesel fuel makes for an excellent light-bodied lube, in my experience.   Looking for any advantage to extend service life, I thought it might help.   I may be wrong

Thanks for the recommendation.  I don't think it will be needed.  Open roller chain drives, such as those used on motorcycles, will last for thousands of hours.  Protect the chain from the elements and run it in a light weight lubricant like the #2 diesel fuel/ATF mix I have in the case, and they're just about indestructible.  I suppose there's all sorts of "magic stuff" a person could dump in there, but I doubt any of it will do any good.

I used a Diado pre-stretched chain in this transmission with chrome pins and brass bushed rollers.  It's the same quality chain you'll find in engine timing chains.  I'm not even remotely worried about it going to hell.
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Chris

[ChrisOlson]

Test running this new machine in the shop:

http://www.youtube.com/user/OlsonFarms?feature=mhum#p/u/6/BNSG8WJjlxI

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Chris

[Fused]

Did you not hit cut in with the same fans on a non geared mill?
In my opinion, I think your low wind output is gone but in your wind zone it will do ok.
Not many of us even get 50 mph winds, much less have a need for a unit that wont reach cut in until high winds rip through.
You say in the video that you can use a smaller, less expensive, more efficient alt, but this is only after the cost of parts for the gear box and custom blades made for you. Im sure the extra expense on the gear box wont save squat on the alternator when the total cost of the build is added up.

Interesting to see anyway.

At least in my crappy wind zone, Ill stick with my 24v cut in at 7 mph wind. 

Fused

[ChrisOlson]

Did you not hit cut in with the same fans on a non geared mill?

The last time I ran a set of blades with fans I used two banks of fans with twin 3/4 hp fans on one stand and a 48" diameter 1.5 hp fan on the other.  And it was a smaller rotor which is easier to get more air movement over the entire swept area when using fans.

With the two fans I was using in the video the wind speed wouldn't even register on my handheld anemometer in back of the rotor.  Probably about 3 mph or so simulated wind speed with air movement on only about 30-40% of the total swept area.  This was not a test to see if I could make cut-in with fans.  This was a test to make sure the rotor is vibration free and the machine won't be a tail wagger prior to cut-in.

This machine will reach 12.0 volts at 6 mph wind speed and 14.0 at 7 mph.  The machine, from the input shaft to the batteries, is 3.2% more power efficient at 600 watts than anything else I've ever built, and came in at 78.7% power efficient @ 80 amps @ 14.5 volts, which beats any direct drive I've ever built for this size turbine by a good 11% @ 1.2 kW output.  And that includes the losses in the rectifier.
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Chris

[Fused]

Who checks wind speed behind the blades?
How can you check for vibration if its not even up to operating speeds?
Why did you use the smaller fans when you say it has a larger dia blade set? ("And it was a smaller rotor which is easier to get more air movement over the entire swept area when using fans.")
Rotor or blades? Rotor wont matter too much on fan size. lol
 You say it will reach 12v in 6mph winds. Well a lot can be figured on paper, but only wind will prove it. After cut in the alt will drag down your blade speed, multiplied by your gearing.

"3.2% more power efficient at 600 watts than anything else I've ever built"
That can be done by no more than a blade profile change. I build my own blades and have seen more than 5 percent improvement by a change of blades, in the same wind.

Fused

[jarrod9155]

I believe Chris is checking the balance at low speed before cut in . I know my machine has a tail wiggle at low rpm before cut in do to a balance issue . I wish I could fit my mill in the garage , 18 foot ceilings is hard to find . As for cut in speed I believe the fans are not as good as real wind test but provide great test results for fine tunning balance  . Looking good

[TomW]

Who needs a fancy wind tunnel when you have a couple large shop fans on tap. 

That prop sure appears to be a long ways from the gearbox. I know you already mentioned it being plenty tough to handle it. I wonder how / if it will affect furling out that far from the pivot?

Nice work and thanks for the share.

Tom

[ChrisOlson]

I believe Chris is checking the balance at low speed before cut in

Exactly.  Most people only static balance their rotor.  Which is great because the rotor doesn't hop and down.  But then they end up with a tail wagger due to a dynamic balance issue.  I prefer to balance both statically and dynamically before the machine goes on the tower.

Who checks wind speed behind the blades?

I do.  Only an idiot would stand in front of the blades and block what little wind is available from the fans.

How can you check for vibration if its not even up to operating speeds?

You obviously don't have the first clue on how to balance a turbine rotor.  So why don't you go read a book on it or something so those of us who actually spend our time building turbines don't have to explain it over and over and over.
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Chris

[ChrisOlson]

That prop sure appears to be a long ways from the gearbox. I know you already mentioned it being plenty tough to handle it. I wonder how / if it will affect furling out that far from the pivot?

Tom, I do that on purpose.  I'm sure you're aware that my turbines don't use angled hinge against gravity furling.  I won't go into details here, as there's other threads on the board discussing what I call "forward lead" of the rotor from the yaw axis.
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Chris

[TomW]

Tom, I do that on purpose.  I'm sure you're aware that my turbines don't use angled hinge against gravity furling.  I won't go into details here, as there's other threads on the board discussing what I call "forward lead" of the rotor from the yaw axis.
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Chris

Chris;

Yep, sorry, I kinda remembered that after I clicked "post".

I suffer from CRS   Can't Remember Shtuff.
Tom

[ChrisOlson]

I suffer from CRS   Can't Remember Shtuff.

LOL!  I guess I have made a few changes in that system from the first one I built.  My other machines turn right, furl right.  On this one I was going to use a turn left, furl right configuration.  But I decided to go with turn left furl left because using the rotor's precession force to help the machine track the wind instead of aiding in furling helps maximize kWh output.  I've also reduced the offset by a couple inches on these 12 and 13 foot machines to keep them into the wind longer, as I like to furl my machines in the upper 30's on wind speed, and see them fully furled around 40 mph, instead of in the upper 20's.

Being I'm flying a different blade profile than what I'm used to on this one, I'll probably back the spring pressure off on the furling a bit until I see how it acts in higher winds.  But the generator is designed to reach peak output of 100 amps at 800 rpm, which is 375 rotor rpm.  Once I get a handle on how this rotor runs in higher winds, then I'll make the final adjustments on it as far as furling.  If the rotor can maintain 5.5 TSR @ 30 mph wind speed, then I'll have my 375 rpm on the rotor and I'll shut this one down a little earlier than I do with my 13 footers.

It's totally possible I may get my 375 rpm with this machine in the mid 20's on wind speed.  From what I've studied on this GOE222 airfoil that was originally used on the old Winchargers, these things like to run and maintain TSR under heavy loads when the wind picks up, and they can be hard to stop.  If that's the case I'll be gigglin' like a kid in a candy store because that's exactly what I wanted in this machine.
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Chris

[Fused]

"You obviously don't have the first clue on how to balance a turbine rotor.  So why don't you go read a book on it or something so those of us who actually spend our time building turbines don't have to explain it over and over and over."

LOL

Ive built 4 wind generators with nothing but hand tools. Never had a balance problem that was not easily repaired. Even at 700 rpm on a 6 foot blade I have no vibration.

Taking a wind measurement behind the blade is meaningless.

Balancing a blade and rotor at 50 rpm will not always show vibration. Its when its up to operating rpm that shakes and unbalance show up.
Those who have built their own know this.

Not going to get into a pissin contest, you can be the king. (lol)

Have fun anyway.

Fused

[ChrisOlson]

Not going to get into a pissin contest, you can be the king. (lol)

Good.  Then I won't have to read about you complaining about everything I do when I build a machine.  I post it here so other people can see something different that few have done in the homebrew world.  Not for people like you tell me everything I'm doing wrong.  If you don't like my transmission, custom blades, or generator, then design and build a 12 foot direct drive and post it so I can at least have a chance to tell you I don't like your setup.  You might not like it, but other people do.

And I assume you've finally come to the realization that you'll never have much of a dynamic balance problem with your skateboard wheels, but you will with your car tires.  I'm sure all you do is static balance rotors.  But dynamic balance corrects both static and couple forces caused by asymmetric mass distribution in the rotor.  You can have perfect static balance in a large turbine rotor, but it will still wag the tail on the machine at low speeds.  I don't like that, so I fix it BEFORE it goes on the tower.

Those of us who build bigger machines just MIGHT have a little different perspective on how to do things since just the blade hub on this 12 foot machine probably weighs more than your whole 6 foot turbine, and the swept area of your machine would only cover the blade roots and maybe 5" of the airfoil on this 12 footer.
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Chris

[JW]

Not going to get into a pissin contest, you can be the king. (lol)

Can't imagion that one going any better.


Chris, your work is top notch, dont change a thing : ) : ) : )

The only thing I would recommend is using "light spindle oil" versa the diesel fuel blend. 

JW

[ChrisOlson]

The only thing I would recommend is using "light spindle oil" versa the diesel fuel blend. 

OMG.  If I dump all this stuff in there that's been recommended, I'm going to have to weld a bigger sump on 'er to fit it all in there   

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Chris

[DamonHD]

Don't forget the magic pixie dust and/or the zero-point magnetic OU stuff!  B^>

Rgds

Damon

[phil b]

Hi Chris,
I've been following this story with great interest. It's nice to see someone thinking outside the box.
Would you mind telling everyone how you dynamically balance your turbine?

[TomW]

Chris;

I still have a lone remaining can of Zubbly's (R.I.P.)  Flux Spray that the NSA didn't confiscate. 

They took all of the S.I.L.N.Y. wire or I would send it to you to try some super coils.
 
After you add all the suggested upgrades you will probably need it to levitate the beast into position.

I, for one,  appreciate what you are doing not following the cookie cutter plans. Obviously it is not for everyone.

We have so many different skill levels of members here from full on reclining armchair warrior wannabes to those who probably make their own magnets and wire, etc that you will never get away from the "why didn't you.." comments.

I appreciate your sharing so don't get discouraged by the odd dissenting comment or 5

Thanks for the many shares here.

Tom

[ChrisOlson]

I still have a lone remaining can of Zubbly's (R.I.P.)  Flux Spray that the NSA didn't confiscate. 

They took all of the S.I.L.N.Y. wire or I would send it to you to try some super coils.

ROTFLMFAO!  That's the funniest dang thing I've heard all day.
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Chris

[JW]

; )

JW

[ChrisOlson]

Would you mind telling everyone how you dynamically balance your turbine?

Not at all.  First I static balance the rotor and set trip tracking just like everybody else does.  That procedure is fairly well outlined in both Hugh's and The Dan's books and it works.

Then I spin the rotor up to a few rpm below cut-in.  If you noticed in that video I had a solid "arm" on the back of the turbine attached to my forklift to keep it from accidentally yawing in the shop.  Rotors that have good static balance but still have a dynamic balance problem will exhibit "tail wag" at low speeds, but it generally goes away at higher speeds.  It's still there but it's not as noticeable at higher speeds because the frequency of the vibration is higher and you can't see it in the tail.

I release the vice grip holding the "arm" to the fork lift and hold on to it by hand.  I have the back of the blades numbered and I can see the numbers going around on there.  If the rotor exhibits a dynamic balance problem you'll feel it as a "pulse" in the arm that you're hanging on to, twice for every rotor revolution - first one way, then the other.  The dynamic balance is a problem with the rotor disc "wobbling", whereas static balance is up and down "hop" or vibration of the rotor.

Dynamic balance problems can be corrected by adjusting tip tracking, just like on a car tire where dynamic balance is corrected by adding weights on one side of the rim or the other, or placing them at a certain spacing on one side of the rim.  On this 12 foot rotor the static balance was perfect with no weights required at all.  But it had a slight dynamic balance problem that I identified as blade #2 causing it.  The tip tracking was also perfect, but shimming blade #2 at the root so the tip tracked 4 mm out from the other two fixed the "wobble" in the rotor.

I ran this thing up to 455 rpm this afternoon on my test stand outside and it runs beautiful.  She's ready to go on the tower.  But I'm going to wait for a bit warmer day to swap it out with the 10 footer that it's replacing.
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Chris

[ChrisOlson]

This is a recap and summary of sorts of what has turned out to be one of the most fun and interesting wind turbines I've ever built.  Here's some photos of the machine from all sides, fully assembled and tested, and ready to go on the tower:









Some of the basic specs:

• The machine is 14' 5" long from the front of the input shaft to the tip of the tail feather.
  
• Actual rotor size is 148" diameter, or 12.3 feet
• I hooked a rotary spring scale on the cherry picker and lifted the machine off the yaw shaft.  It ended up just a big heavier than I expected - 237 lbs
• The machine is pretty well balanced on the yaw shaft, but slightly nose heavy to the tune of about 5 lbs required on the tip of the tail to balance it.  This is good, as in normal operation the rotor thrust will almost perfectly balance it on the shaft, meaning less wear to the shaft bushings and needle thrust bearing on the bottom of the yaw tube.
• The generator design was decided on after about a week of testing various configurations to see what would work with a gear driven unit.  That was all well discussed earlier in this thread.  The generator was tested to 136 amps (this is a 12 volt machine) and is rated at 80 amps continuous, or about 1,200 watts.  It's wound with 30 turns of 12 AWG, 12 pole 9 coil configuration with 10" diameter generator rotors, and runs at 2.14x rotor speed.

The blades are from DaveB and DaveM at Royal Wind & Solar in Jamestown, NY.  They are Gottingen 222 Hi-Torque airfoils and the blades have no twist or taper.  Those guys are superb - I ordered the blades about a week after I started working on the machine and they had them carved, shipped and to my door before I was ready for them.  I wanted the lightest blades possible for this machine so they're made of poplar.  They use a sealer on them that raises the grain of the wood a bit, so after sanding them out smooth and priming, I painted them with three coats of DuPont Imron with Delthane hardener in GM Olympic White.  This is a photo of the blades after they dried and before I mounted them to the hub:



And finally, a high output 12 volt turbine needs a high capacity rectifier, so I built this unit using a 195 amp rectifier stolen out of a Leece-Neville/Prestolite truck alternator:



This turbine will have two 8/3 generator cables down the tower to the base junction, and 1/0 copper buried underground from the base junction into the service panel in the house.  You can't stator brake a high-output 12 volt turbine thru the line because they'll just keep right on running fully shorted.  So the stator brake switch is located at the base of the tower and is a 100 amp rated GE three-pole safety switch with the fuses removed and replaced with lengths of copper tubing.  This machine is outfitted with a tail crank - the cable guide is installed in the yaw tube alongside the generator cables and attaches to the spring bracket at the rear top of the generator.  The cable attaches to a stud on the tail boom and goes down thru the center of the tower to a small winch used to crank the tail into the furled position.

So that's about it.  Pretty fun machine to build.  Hopefully we'll get a nice day soon when I can work outside and get it on the tower.
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Chris

[kensue49]

We lurkers and arm chair builders who have been taught so much await the flight of your machine.
We hope that it performs as you have designed it.

[Dave B]

Great photos and write up Chris. That is a one of a kind turbine and it will be very interesting to learn from your design after it's up and flying also. We may have carved the blades (and thank you for the fine words) but you have finished them top notch like no others and unless you loose them into the next county (highly unlikely with your custom hub) these should serve you well for a very, very long time. We are excited about your geared machine and look forward to your future posts. I have thoughts of a 20' maybe larger lazily turning 100 RPM or so with a transmission such as yours spinning up an axial alternator. At the lower speeds I would think the furling tail could be back in the game as a viable set up for high wind and speed protection. With this blade profile and direct drive I've burned up 2 stators and "trimmed" a set of 18' blades with the tower to 16' (these are hanging on our outside wall of the shop now). I think with your gear up transmission and depending on the load it should help hold the blade acceleration in check. I shoudn't talk I guess, it took me 3 tries to get what I finally have now under control. You will have fun and we know that for sure. Thank you for posting for all to read and see, I know I am really looking forward to your future updates on this project.  Dave B. 

[poco dinero]

Hi Chris,

Congrats on your innovative wind turbine.  I hope someday you will publish a book.

a 100 amp rated GE three-pole safety switch with the fuses removed and replaced with lengths of copper tubing

Could you please let us know the model number and cost of this GE switch?  Also your source.  Every time I ever wanted a one hundred amp three-pole safety switch it was made by Siemens or Schneider and very expensive, like a thousand smackers.

Great description of your system of dynamically balancing your rotor.  I never would have thought of that.  I bet nobody else on this forum does that.  Some of them don't even seem to understand the difference between static and dynamic balance.   Thanks a bunch.

poco

[clintonbriley]

They are Gottingen 222 Hi-Torque airfoils and the blades have no twist or taper.

Other than ease of manufacture, is there any particular reason the blades are made without any twist or taper?

[Janne]

The way you do dynamic balancing sounds interesting. I've always thought it would be beyond reach, at least without expensive special equipment.
I like how the machine turned out, can't wait to see the video of it actually running on the tower. Many thanks for the share.

[dsmith1427]

Great work!  Thanks for sharing.  I have learned a lot from your posts and appreciate it very much! 

[fabricator]

Chris, your dynamic balance method is pretty much exactly what a tire balancer does, they just got sensors and chips to be able to do it at a little higher speed, and all you got is the MK 1 brain and the MK 1 Version 1 sensor package.