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Forum Index : Windmills : Vawt...going in a big way

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Xmaswiz
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Joined: 14/04/2011
Location: United States
Posts: 69

Posted: 10:42pm 10 Jun 2011

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that�s ok, I have similar problem, acting before thinking it out. I just didn't want you to think badly of yourself,and I never thought you were acusing at all. and remember they are a whole class of engineering students, with pretty much unlimited access to resources, materials, machinery, and anything else they may have needed or wanted.

Santa Maria, CA.
Noel

mac46

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Joined: 07/02/2008
Location: United States
Posts: 412

Posted: 10:52pm 10 Jun 2011

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Xmaswiz, and Everyone,

Yes, you are quite correct about the nearly unlimited resources...and did you notice the $80,000 price tag on that baby?
I certainly hope that the tax assesor dos'nt think my mill cost that much to build. I'd be paying more in tax than I get returned from electric power.

...Mac46

I'm just a farmer

Greenbelt

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Joined: 11/01/2009
Location: United States
Posts: 566

Posted: 11:55pm 10 Jun 2011

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mac46,

You can say something Bad about My Mother! If you haven't already !

In no way did I mean to Imply that you copied your Design.
One look at the Talent and ability you have displayed is evidence that you do not need to indulge in stealing the Baby's Candy.
I did Try to convey, (Jokingly) that the university's Mill was a stolen blueprint of your Mill and they screwed it up.

I don't always write what I'm Thinking about. Sorry it's Face value was upsetting. "Read my signature"

-------Cheers, RoeEdited by Greenbelt 2011-06-12

Time has proven that I am blind to the Obvious, some of the above may be True?

mac46

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Joined: 07/02/2008
Location: United States
Posts: 412

Posted: 12:16am 11 Jun 2011

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Greenbelt,

I find it a very rare day when I say or think such things about peoples mothers, or anyone else, I strive to think "good things, always". It helps to make the day go better.
I know you did'nt, and I read you'r impression that "they" stole my idea...uncanny resembleance though, 4 legs, 3 wings, ect. Where or how did you find this thing?
I did a search of my scan files...and it was the very first document scanned after I purchased this computer, dated back in 2008, scan #0001, not that it matters.

Thank you for the kind compliment about my abilities, and truely, you'r comments were not upsetting, the fact that a university had already built one, startled me, and sent my mind in a tizzy.

-----Good talking to you again,

....Mac46

I'm just a farmer

Greenbelt

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Joined: 11/01/2009
Location: United States
Posts: 566

Posted: 05:14am 11 Jun 2011

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mac46,

I found this University Turbine article from the top of this index page "IN THE NEWS"
and thought that maybe you could keep tabs on development and maybe pickup some useful
tweaks.
It looks like no sharing of technology at this site , the pic's are about as good as none IMO, No loss,"The Fire that burns within the Heart of Man, will endure", from the Movie Mad max (The Road Warrior)

---------Cheers, Roe

Time has proven that I am blind to the Obvious, some of the above may be True?

mac46

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Joined: 07/02/2008
Location: United States
Posts: 412

Posted: 12:31pm 11 Jun 2011

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Greenbelt, Everyone,

To answer you'r original question, "Would 10 killowatt be enough"...

Yes, and then some, I could power the neighbors home as well and still have excess power left over.
I don't follow what role the university students played in this project, other to monitor and take readings. Sounds like it had a Japanies designer and used contractors from the area to build it. How much fun could that have been?
Yes you'r correct about the info being kept close to the chest, and the photo being nearly useless for showing enough info to tell what they are up to and how they are doing it.
I'm going to take an educated guess and say that perhaps "theirs" is spun up to speed by a motor of some kind, hence the clicking sound after reaching speed and then the quiet...could be way wrong though.
I was surprised at the incanny resembleance to my mill, I'm sure there will be others to follow, and if asked I'll be glad to share my experiances and thoughts.
Thanks for posting the artical, I would guess that there may be other simular mills as well, its a small world.

....Mac46

I'm just a farmer

Rastus

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Joined: 29/10/2010
Location: Australia
Posts: 301

Posted: 03:32pm 11 Jun 2011

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Hi Mac46,
it's been my exsperience that it's quite rare for students to "stumble" across something unique.Generally they are trying to understand and grasp what has already been accomplished.A more common situation is they reference so much of others work the lecturer is often weighing up how much plagerism is evident.You may have been a reference that was of assistance to these students.Don't completely discount the possibility!The internet is a huge arena!There are historical accounts of independent researchers simultaneously working on projects achieving almost the same results within wks or months of each other and taking 50yrs to decide who gets the credit.Just my take on it.Others will pprobably state the complete opposite in their defence.Cheers Rastus

see Rastus graduate advise generously

mac46

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Joined: 07/02/2008
Location: United States
Posts: 412

Posted: 06:09pm 11 Jun 2011

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Rastus, Everyone,

I agree with everything you have said about university students, or any student as far as that goes, but we are all students, and still learning.
What I'm building certainly is'nt cutting edge technology either, and so I am not looking for any credit or a place in the history books, I just want to develope a turbin that will power a few things here on the farm. The vawt has strange tendenceys and I would like to better understand these, and possibly refine it into a more useful machine for anyone and everyone...Just as we, "The Back Shed" people are developeing and refineing the hawt mills.
Thanks for posting Rastus and thanks for veiwing.

....Mac46

I'm just a farmer

mac46

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Joined: 07/02/2008
Location: United States
Posts: 412

Posted: 11:25pm 13 Jun 2011

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Everyone,

I think the storms are running on railroad tracks and are doing real good at staying on a schedule...shure makes getting something done difficult.

you know that "mud" spelled backwards is "dum", Mom always told me..."stay out of the mud".

I don't have much progress to report or talk about, but I am working on building the break system.

....Mac46

I'm just a farmer

Air Bender
Senior Member

Joined: 25/01/2011
Location: Australia
Posts: 206

Posted: 08:20am 14 Jun 2011

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Hi Mac46

I had storms for a couple of weeks but for the last 2 days i have had no wind with the mill sitting idle.
I think the braking system on a vawt is a dificult one to solve. As i am planing to build bigger wings soon and have been thinking a bit about a brake. As i dont want to completly stop the mill in strong winds just keep it slowed down, I have gone off the idea of some kind of friction brake as you will always have the problem of heating up and quickly wearing.
At the moment i am looking at ways to manipulate the wings to keep it at a reasonable speed. I have had some seccess at this so far, but it is an underpowered mill which has made it easy, but hopefully that wont be the case down the track.

All the best Dean.

mac46

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Joined: 07/02/2008
Location: United States
Posts: 412

Posted: 11:25am 14 Jun 2011

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Air Bender,

I have serious concern for running the mill during a high wind event. It appears to me that the force of loading and unloading the wings as they rotate into and out of the wind has a flexing effect on the mill and sets up a resenating vibration...some model vawts have been distroyed because of this effect.
Keeping the rotation speed down and controlled will help for sure, stopping it during storms would be even better.
A small air plane can lift off the runway at 60 mph or even less , so this gives you a good comparison as to what a wing is cappable off lifting and how much lift it can generate in higher winds.

....Mac46

I'm just a farmer

Xmaswiz
Regular Member

Joined: 14/04/2011
Location: United States
Posts: 69

Posted: 04:02pm 14 Jun 2011

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you may want to use a centrifugal (is that a word LOL) driven set of inner blades to disrupt the airflow to the outer blades. or even a set of weights driven out to increase load, or a combination of brake (very large disk or multiple disk) air disruption and counter weights.

Santa Maria, CA.
Noel

Xmaswiz
Regular Member

Joined: 14/04/2011
Location: United States
Posts: 69

Posted: 04:41pm 14 Jun 2011

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did you say that you would also be driving a compressor? if so I immagine that could also be used in some way to slow down the mill?

Santa Maria, CA.
Noel

mac46

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Joined: 07/02/2008
Location: United States
Posts: 412

Posted: 04:48pm 14 Jun 2011

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Xmaswiz,

Yes, I plan on running a compressor...mainly for this very reason, to help load the mill and keep it under 200 rpm. Also air tools are nice to have in the shop, saves alot of time, but takes alot of power to keep the pressure up, especially if I'm doing lugg nuts on wheels.

....Mac46

I'm just a farmer

VK4AYQ
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Joined: 02/12/2009
Location: Australia
Posts: 2539

Posted: 02:20pm 15 Jun 2011

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Hi All

Just a suggestion for you guys playing with VAWT, many years ago I built a small mill it was 10 foot in diameter and 12 foot high with 5 blades cord of 24 inches. It was an experiment to see if smaller ones would be useful and it was a reasonable success.

For the lower section I used a 1 tonne truck diff (pickup if in the States)
I locked up the diff by welding the planetary gears,and welded a block off plate on the lower axle tube. the mounting flange on the bottom end was welded to a larger plate anchored to a cement block. The other end retained the brake drum and brakes for breaking it worked ok except in high winds so you had to stop it before it was too windy. The drive was taken out the pinion with the diff filled up with ATF to reduce oil drag step up ratio was 4. something to one giving around 600 RPM a useful speed and the whole thing cost me $10 at the scrap yard. A shaft from the bottom of the mill connected to the old differential.

It worked on the farm for years without trouble until neglect set in and the diff run out of oil.

I have been thinking of building a smaller one using Phills Geo 222 blades, around 8 ft diameter by 10 ft high with 7 blades, still just a dream though.

All the best

Bob

Foolin Around

mac46

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Joined: 07/02/2008
Location: United States
Posts: 412

Posted: 03:09pm 15 Jun 2011

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VK4AYQ'

Suggestion noted...thanks for posting this!!!

It appears as though I am duplicating you'r "small mill" experiment. Well, at least now I know for sure that "it" can be done, and actually "has" been done.
It is interesting to see that you also stopped the mill during high wind events, as well as other things, it sounds like the two mills have simular traits, and tendencys...other than mine has'nt turned a lick yet, vrs. you'rs that ran for years. To say the least, its a huge inspiration. I'd also be very interested in the large dia. homemade generator you built, (you mentioned this in passing in one of you'r early posts), I have'nt been able to find any discription of it in my search for information.
I'll say this..."actual hands on" experiance will teach a guy just as much if not more than any amount of study reading books...this is where my brain works its best, a person has to figure it out...think, compare, wonder, and "rethink."
I'm afraid that I have blown the $10 buddget out the window, although still with in reason in my book.

....Mac46

I'm just a farmer

VK4AYQ
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Joined: 02/12/2009
Location: Australia
Posts: 2539

Posted: 02:16am 16 Jun 2011

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Hi Mac

The large alternator I build was designed foe slow speed and getting the magnet speed from large diameter, it used Mil disposal magnets 2" dia bar magnets out of a old radar I think, it was an iron core so cogged like all hell and was hard to start, I used a centrifical clutch to get it going. it used switching in the poles for load control and around 150 rpm produced 10 KW + power on 32 volts.

I wouldn't go that way again as i feel the air core is a better proposition, I have ordered some ferrite magnets to have a play with as Neomagnets are out of the question now, silly thing is I can buy a 5 KW vertical alternator cheaper than I can buy the magnets (neo) to make one.

ferrite magnets 64 of 75x50x20 mm $384 same size in neo $3400 big difference. plus freight on both.

All the best

Bob

Foolin Around

mac46

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Joined: 07/02/2008
Location: United States
Posts: 412

Posted: 05:02am 16 Jun 2011

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VK4AYQ,

Thank you for responding to my request on this...this helps clearify things for me and gives me a referance point. Like I said, the basic therory has been floating around in my head for a couple of years...but I have'nt worked the numbers or got down to any serious plan. I conculded that I needed to have a working vawt and test it for speed and torque, start up charictics, ect.// thats why all the study and tests on the wing profiles. (Hey it works on paper)...but we've all herd this before. Thats why when I read that you have "been there done that already", really gave me a shot in the arm.
Yes, I've read that the price of rare earth magnets is sky rocketing, Nasa is working on a composite material that looks very promiseing and may replace the Neomagnets, but no one has said anything about the price yet.

....Mac46

I'm just a farmer

mac46

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Joined: 07/02/2008
Location: United States
Posts: 412

Posted: 01:05am 17 Jun 2011

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Vawt, going in a big way...

Ok, back to the project,
I have installed the break system, the break is set and holding the mill...however, there is'nt a hint of a wind out there right now. I still have a few corner gussets to weld on and a carrier spring to hook up, but the break is more or less installed and nearly finished. Sorry, no picture.

....Mac46

I'm just a farmer

mac46

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Joined: 07/02/2008
Location: United States
Posts: 412

Posted: 10:19pm 17 Jun 2011

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Vawt, going in a big way...

I have now completed the break system. There is'nt any wind to speek of, I'm out of luck as far as starting any testing. (There must be some truth to the saying that there will be no wind for several days after completeing you'r windmill).
I have'nt installed the batteries, the wireing, ect. but it is complete enough to start testing. I'll start installing batteries and stuff in my spare time.
I had to order in a 60 amper guage, no one had anything instock, also picked up a voltage guage and battery disconects.
I noticed that the farm store carries 50 and 60 amp. spade / plugin DC fuses, might have to pick some up and make up some of Glens neat little fuse holders.

....Mac46

I'm just a farmer

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