CNC Machined Wind Turbine

[mroy0404]

Hi Guys

My wife and I have been working on this 61" Dia. wind turbine this past spring. We machined most components from solid 7" dia. 6061-T6 aluminum. The blades are Raptor Gen 4 and the PMA is a Patriot from sun born energy. Also all bolts are 304 stainless steel to keep it rust resistant. There is a 50 Amp slip ring fitted perfectly with 2 over sized sealed bearings for the yaw motion. The PMA also has to sealed bearings  for smooth support.
We have tested a prototype and have seen power output of 18.6 volts and 40 amps! We figure these numbers looked great.
Afew friends have shown interest so we have machined up 4 more units. I have attached afew pic's and a link to my photobucket page. Could you guys give me your thoughts?
Enjoy

Mike Roy in Canada

http://s41.photobucket.com/albums/e288/mroy0404/Wind%20Turbine/

[Mary B]

40 amps into what? And at what wind speed? Output curve versus wind speed into a battery is needed.

[birdhouse]

it sure looks nice!  though looking nice and performing well can be two different things, though from your intro, it sounds like you build well! 

it looks to not have any furling, so it better be strong enough to head into big winds! 

is this a battery tied system, or for grid tie??  the ~18v and 40A make me wonder.  sure that is ~700w, but no 12v battery is going to be happy at 18v! 

i hope these aren't slated to be installed on rooftops!   

adam

[keithturtle]

Looks good; now install it, get some performance numbers and post them here.   Will probably need an MPPT controller for charging 12V, may help getting best power from a smallish disk.

Turtle, slow

[mroy0404]

Thanks for the reply Keith, I have looked around online and found many different MPPT controllers. Could you recommend 1 for me?

[mroy0404]

Here are afew more pic's of our turbine project!!

[tanner0441]

Hi

How have you measured the 40 A and 18 V?  What was the shaft speed and load? As mentioned earlier 18 V into a 12 V battery will fry it. 18 V into a 24 V battery won't charge it. I don't see that size blade set doing 720 W very often.

What height tower is it going on? What is your wind area?

It is well made and I would love your CNC machine, but there are units on here made from bits of car suspension and brake discs that output real power.

Post some test figures.

Brian.

[fabricator]

Very pretty, I wish I had a CNC machining center in my garage Please, loose two blades, one blade is best two blades are better and three blades are the best trade off because of balance, vibration, and turbulance considerations, five blades are holding your machine back.

[thingamajigger]

@mroy0404
That's a great looking machine and we could definitely use more people building quality machines which hopefully enter the market at some point, having more options is a good thing.

@tanner0441

How have you measured the 40 A and 18 V?  What was the shaft speed and load? As mentioned earlier 18 V into a 12 V battery will fry it. 18 V into a 24 V battery won't charge it. I don't see that size blade set doing 720 W very often

Tanner the year is 2012 not 1912 and in this day and age we can buy or build cheap power controllers to regulate power in any way we choose. So your concern over the voltage is somewhat pointless, the thing to remember is Watts are Watts and it is super easy to convert power at one voltage to another at a very high efficiency.
To put this into perspective I'm working on an open source controller using a microcomputer the size of a postage stamp which regulates the voltage up or down (boost/buck) as well as a function to map the RPM/power curve (MPPT). This is nothing new or all that innovative in my opinion however being able to build a 1 to 3 Kw smart controller from a kit with free open source software for around $60 is. The year is 2012 and I think we can do better.

Regards
Thing

[mroy0404]

@ Thingmajigger

Im interested in your microcomputer power controller, could you email me at mroy7@cogeco.ca with more info. about your project.

[CraigM]

@mroy0404

I've worked as a job estimator at an aerospace machine shop for many years and can see from the photos taken that your machine work is flawless and this is a professionally built piece of equipment.

I've also spent the last half year not building but researching and reading all I can on wind turbine design. One reoccurring theme that comes up often on this forum is the distain for reworked automotive type alternators used for wind turbines.  Most output claims made by the manufacturers of these units are wildly exaggerated and usable power only comes with very high rpm's and very high wind speed.

With the 61” blade diameter the betz limit of 59.6% wind efficiency would require a wind speed of nearly 23 mph to reach the output figures (720 watts) you've given. Since this is the theoretical maximum efficiency even a highly efficient good wind turbine would need nearly 30 mph winds to reach greater than 700 watts with 61” diameter blades. This link has been posted many times and I've never seen the data challenged. http://www.ndsu.nodak.edu/ndsu/klemen/Perfect_Turbine.htm

Most areas of the world rarely see 30 mph winds and because of this increasing blade swept area combined with high output low rpm generators are the keys to making usable power in the most common 10-20 mph winds.

With a 61” blade diameter you may average around 100 watts in 15 mph winds.

Don't wish to rain on anyone's parade only to provide a real world scenario. Please disprove me by providing the data as suggested by MaryAlana.

40 amps into what? And at what wind speed? Output curve versus wind speed into a battery is needed.

and Tanner0441

How have you measured the 40 A and 18 V?  What was the shaft speed and load? Post some test figures.
Brian.

CM

[tanner0441]

Thingamajigga

I am aware of the year and the fact there is very cleaver electronics out there, but. You can't get something for nothing, if the wind isn't blowing hard enough you wont even need a controler, also what you have to remember (a point made to me a few years ago) this site is read by people in countries where they don't have access to some of the electronics we have. and the output versus shaft speed is a viable question.

I am not decrying the build quality or presentation, all I am asking for are a set of figures for the turbine performance, and your postage stamp controler cannot get 200W from a 50W wind.

Brian.

[mroy0404]

@mroy0404

I've worked as a job estimator at an aerospace machine shop for many years and can see from the photos taken that your machine work is flawless and this is a professionally built piece of equipment.

I've also spent the last half year not building but researching and reading all I can on wind turbine design. One reoccurring theme that comes up often on this forum is the distain for reworked automotive type alternators used for wind turbines.  Most output claims made by the manufacturers of these units are wildly exaggerated and usable power only comes with very high rpm's and very high wind speed.

With the 61” blade diameter the betz limit of 59.6% wind efficiency would require a wind speed of nearly 23 mph to reach the output figures (720 watts) you've given. Since this is the theoretical maximum efficiency even a highly efficient good wind turbine would need nearly 30 mph winds to reach greater than 700 watts with 61” diameter blades. This link has been posted many times and I've never seen the data challenged. http://www.ndsu.nodak.edu/ndsu/klemen/Perfect_Turbine.htm

Most areas of the world rarely see 30 mph winds and because of this increasing blade swept area combined with high output low rpm generators are the keys to making usable power in the most common 10-20 mph winds.

With a 61” blade diameter you may average around 100 watts in 15 mph winds.

Don't wish to rain on anyone's parade only to provide a real world scenario. Please disprove me by providing the data as suggested by MaryAlana.

40 amps into what? And at what wind speed? Output curve versus wind speed into a battery is needed.

CM

@ Craig
Thank you for the compliment, I have been a Tool & Die maker for the past 17 yrs. This type of work is relaxing for me to do at my home shop. We will be doing some real world testing very soon and will keep everyone up dated with honest results. I'm very open too any one's advice for any improvements to this design or setup.
Anyone with advice is more then welcome to add to this thread, I will test any idea's you may advise.

[fabricator]

I believe thingamajig is the member that does not believe in the Betz limit, the unit is absolutely beautiful though except for the newbie mistake of 5 blades.

[mroy0404]

Thingamajigga

I am aware of the year and the fact there is very cleaver electronics out there, but. You can't get something for nothing, if the wind isn't blowing hard enough you wont even need a controler, also what you have to remember (a point made to me a few years ago) this site is read by people in countries where they don't have access to some of the electronics we have. and the output versus shaft speed is a viable question.

I am not decrying the build quality or presentation, all I am asking for are a set of figures for the turbine performance, and your postage stamp controler cannot get 200W from a 50W wind.

Brian.

@ Tanner

I have only tested the unpainted aluminum prototype so far, the power was measured with a simple automotive digital volt/amp in line meter before it was feed to a 1000 watt grid tie power inverter. The 18v with 40 amp reading was taken when we had higher then normal wind speeds 1 night about 1 month ago. The test unit is not placed in the best position, so we will be installing the coated (white power coated unit) in the country hopefully later this week. The install will only be set up to charge a 12v deep cycle battery. Bill my friend in the country will be setting up a live webcam along with real time weather reports so anyone can see real time results. I will post this link here for all to see.

[CraigM]

All of that beautiful work designed around yet another Delco PMA is what makes me cringe. Sorry Mike, the output of a delco type PMA is limited by its size. You can only get so many magnets and copper wire into its given dimensions and the size limitations make it a 12 volt trickle charger at best unless you're spinning the bejesus out of it. To get the higher rpm's needed take Fabricators advise and use three possibly even two blades.

This very well could be a profitable venture for you, as much of the general public seems to favor a smaller less obtrusive machine. With the man/hours and materials you have invested I'd hazard a guess that you'll need to price this at $2000 or better to make it profitable. Hogging out 7" diameter bar stock takes some run time.

All in all wonderful work.

CM

[mroy0404]

@Craig
I will make up a few more hubs and nose cones with 2 and 3 blade set up to test with the same unit we install next week, this will be interesting to see how much of a difference it will make to the power output. I have been thinking about machining the front housing to accept a thin planetary gear(maybe 1.5:1 or 2:1). do you think this design would work? or do you think the planetary gear could just increase the resistance beyond the blade capacity to turn?

[fabricator]

It would be worth a try, I'd start at 2:1.

[thingamajigger]

@tanner0441

I am aware of the year and the fact there is very cleaver electronics out there, but. You can't get something for nothing, if the wind isn't blowing hard enough you wont even need a controler, also what you have to remember (a point made to me a few years ago) this site is read by people in countries where they don't have access to some of the electronics we have. and the output versus shaft speed is a viable question.

I am not decrying the build quality or presentation, all I am asking for are a set of figures for the turbine performance, and your postage stamp controler cannot get 200W from a 50W wind.

Maybe I didn't explain myself properly, I wasn't implying we can get something for nothing I was trying to say we can get more of what is already present. Let's put it this way, I have a turbine which runs at X RPM in a wind at velocity Y however the RPM is not sufficient to generate the 12.4 volts required to "cut-in" and charge our batteries. Now we can just let it spin away and do nothing or we could convert part of the potential current flow through a low resistance inductor to a higher voltage which will charge our batteries. This is the basis of boost conversion, we trade current for voltage, watts remain near constant minus conversion losses however now we are charging our batteries.
We should remember "Energy" is power over a span of time measured in Watt/Sec or KW/Hr's and energy is all that matters not power. So if I generate the same power for the same time above cut-in I have generated the same amount of energy as you however if I also generated one half as much power for twice as long below the average cut-in then I have generated twice as much Energy as you have. Or if I generated one quarter the power for four times longer below the average cut-in then I have still generated twice as much energy as you have and this is measured as real energy by a watt/hr meter like the one on the side of your house. It is not something for nothing it is intelligent design and control to convert the maximum amount of energy inherent in any wind at any velocity into electrical energy which is our goal.

@Fabricator

I believe thingamajig is the member that does not believe in the Betz limit

I also believe in unicorns and fairy dust, cool huh?.

@mroy0404

This type of work is relaxing for me to do at my home shop. We will be doing some real world testing very soon and will keep everyone up dated with honest results. I'm very open too any one's advice for any improvements to this design or setup.
Anyone with advice is more then welcome to add to this thread, I will test any idea's you may advise.

I enjoy building as well and it is hard to beat the sense of satisfaction when we do something ourselves even if it tends to blow up in my face half the time. I think your on the right track and honest results with real world testing will always pay in the long run. It may also help to build a generic hub to test different blades and blade geometries however these often show only small incremental gains. However many small improvements acting over a long period of time can add up to some pretty big numbers.

Regards
Thing

[tanner0441]

Hi

If you can keep it oily an epicyclic gear train would be a first I have seen on here in a home build, there are a few on here with lightweight chain drives, and V and notched belts.  I would think the torque could be easy to measure with a reactive mount on a test motor driving the prototype. ie. motor on a swinging mount with a spring balance as the third mount, and a prony brake with weights as a load.  You are not looking for absolute figures only the losses in the gears. You can work out the power produced by the blades easily enough

My own unit is a 78 inch blade set and even though my wind area in the UK is crapp, it doesn't do the rated output, 200W, very often though I have seen double that twice. My unit has bearings on the yaw and I am not sure it is the way to go it is very free and swings about too easily, the greased tube over tube has better resistance to swinging and it slows the yaw down a bit.  The observed output of my unit is cuttin around 360 390 RPM depending on battery state of charge and rated output at 450 RPM.

How do you regulate the speed from running away if the load reduces. You have no furling or obviouse mechanical braking.

If I had your machining facilities I would be looking at making an X,Y,Z  CNC router to churn blades out.  Just a thought.

Brian.

[CraigM]

@Mike

That last question was beyond my comfort level so I'm glad others helped out. Brian aka Tanner0441 made some very good points. Much of the challenge is matching the power your blades can extract from the wind to the power output of the alternator. I.e. small blades on a more powerful alternator will cause the alternator to stall the blades and limit output. Larger blades on a less powerful alternator will cause the blades to over speed not allowing their full potential.

A planetary gear would be a first... and a very compact design I might add.
CM

[mroy0404]

@ Craig

I have never sourced a planetary gear set up in my past, would you have any idea where I should look for this type of item?

[CraigM]

@Mike

I'm located in Arizona and our engineers used to source stepper motors from a company in California called Anaheim Automation. I believe they also carry planetary gear boxes although I've never used them for this application.

[Frank S]

@ Craig

I have never sourced a planetary gear set up in my past, would you have any idea where I should look for this type of item?

A good source of planetary gears for a system such as yours would be to look at scrap automatic transmissions.
 in simple terms think of them as Sun planets and ring for your machine or about any other the internal ring gear would be turned by the turbine the planets would be mounted to a fixed spider the sun would be connected direct to the rotor
 the ratios would be pretty easy to determine say  the ring "R" has 60 teeth the planets "P"15 would be  "R"@1 rev = "P"@4 rev then the sun "S"say 21 teeth  would be P@4r= "S"@ 2.8571 close enough then if you needed your stator to spin @ 1200 RPM the turbine would need to spin 420
 someone mentioned epicylipic 'spelling' I once had a small electric winch the crazy thing had only 2 ring gears and 3 planets and 1 sun gear but it had a 300 to1 reduction, this was accomplished with a play on backlash tolerances 1 ring the drum had 200 teeth the planets were long enough to connect to a second ring gear having 1 tooth less the spider was floating while the sun gear was the motor shaft. This was an insanely obscene design, designed for self destruction from the first time it was used but it worked and worked well for a while the winch was the super winch MX3 I used it for a bout a week with a block & tackle to lift 5000# pipes 10 times a day at the end of the week the little gears were worn nearly smooth because of the 1 tooth difference
 Most Gear reduction manufactures are not going to be able to understand or will be willing to assist in using their gear sets without their housings However Blevins  gear Company may be a good place to look

[fabricator]

Hi

If you can keep it oily an epicyclic gear train would be a first I have seen on here in a home build, there are a few on here with lightweight chain drives, and V and notched belts.  I would think the torque could be easy to measure with a reactive mount on a test motor driving the prototype. ie. motor on a swinging mount with a spring balance as the third mount, and a prony brake with weights as a load.  You are not looking for absolute figures only the losses in the gears. You can work out the power produced by the blades easily enough

My own unit is a 78 inch blade set and even though my wind area in the UK is crapp, it doesn't do the rated output, 200W, very often though I have seen double that twice. My unit has bearings on the yaw and I am not sure it is the way to go it is very free and swings about too easily, the greased tube over tube has better resistance to swinging and it slows the yaw down a bit.  The observed output of my unit is cuttin around 360 390 RPM depending on battery state of charge and rated output at 450 RPM.

How do you regulate the speed from running away if the load reduces. You have no furling or obviouse mechanical braking.

If I had your machining facilities I would be looking at making an X,Y,Z  CNC router to churn blades out.  Just a thought.

Brian.

This thing is as far from a home build as they get, that is a CNC machining center in that picture, how many people have them in their garages?

[mroy0404]

@ fabricator

I like having my CNC Machines at home. makes going to work way easier!!!

[fabricator]

Hell yes, I'd like them too.

[Bruce S]

@thing;
Let's do this going forth. Before you go remind people of the year STOP and try not typing something that could be misconstrued as trying to be rude.
Telling tanner the year is 2012 and not 1912 was close , and had he complained I'd been on here even quicker.
A whole lot of people do in fact see this forum from places you may not believe and certainly do NOT have access to the electronics we enjoy.
poke around some of the stuff done south of the equator.
ON the old board there used to be a notice of posting with a smile on your face, let's keep it 
Cheers;
Bruce S
 

[OperaHouse]

Frankly I think saying   "18 V into a 12 V battery will fry it. 18 V into a 24 V battery won't charge it." is just as rude.   

[Bruce S]

Frankly I think saying   "18 V into a 12 V battery will fry it. 18 V into a 24 V battery won't charge it." is just as rude.

Had it been put that way in a single sentence, they yes , I would agree, however no snide remark was made and it was in a question mode in trying to get additional information.

[thingamajigger]

@Bruce S
I understand what your trying to say and agree, I got a little irritated by tanners post because I believed it was kind of like saying -- man cannot fly. I see many people spreading completely outdated information which may have been true 30 years ago but not in this day and age which is why I made a point of reminding tanner what the years is. I hope you can appreciate my perspective as I see little difference between people speading outdated and false information and the people selling the preverbial "Delcos" generating megawatts,lol, both are false and do no justice to people who do not know any better.

Let me put this in a little better perspective, Im a Power Engineer which is defined as an expert in energy systems, energy conversion and distribution, I built my first cogen unit(heat and power), wind turbine and solar thermal heating units when I was 13 and have continued extensive R&D in every aspect the renewable energy sector since that time. I have operated in power plants the size of small towns --- then Fabricator implied I don't understand the Betz limit and Tanner implied I don't understand we can't get something for nothing or as I call it the conservation of energy ---- Now how would that make you feel? and what would be your response to their condescending statements?.
To be honest I thought I was being quite polite because if anyone ever said those things to me face to face I can give you my personal guarantee they would get a lecture the likes of which they would never forget.

Regards
Thing

[tanner0441]

Hi

Lets not hijack the post with an argument, I was not offended by the comments, and believe everyone is entitled to an opinion, even if it differs from others opinions, this is when all said and done a discussion board to thrash out ideas. Look at the crap Steadfast put up with and how much he has learned and is putting into practice.

As for what people do for a living I am a retired marine electrician and I could be asked to work on UK, US, or Italian wiring systems ranging from 110 to 440V three phase, and when your up to your ankles in sea water that focuses the mind. I have also worked on Vickers variable pitch pumps 11000 V and mercury vapour rectifyers, much prettyer than solid state and much much more impressive when they blow up, so you don't take short cuts with those.  I was deemed an expert in my field but I always repplied an ex is a has been and a spurt is a drip under pressure..

For the origional thread I am impressed with the machining center and the standard of work being done on it and if I had the funds and room. I would be happy with an old Bridgeport, but with that equipment it lets people push boundries and by posting the information others will see a simpler albeit slower way to copy it.   Because of the ease of changing the program parrameters it makes it posible to test and fine tune or reject things which can then be copied, but however neat a device is there has to be a benchmark for comparisons.

Brian.

[thingamajigger]

@Tanner0441

Lets not hijack the post with an argument, I was not offended by the comments, and believe everyone is entitled to an opinion, even if it differs from others opinions, this is when all said and done a discussion board to thrash out ideas. Look at the crap Steadfast put up with and how much he has learned and is putting into practice.

I agree 100%, I tend to take things out of context and get frustrated with myself that more progress is not being made towards better and cheaper turbines everyone can afford, and tend to take this out on other people. I think I need to get back into my own element and to be honest this ain't it as everyones answer always seems to be 3 wooden blades and an axial flux generator. Cutting edge R&D is what interests me and this may not be the place to discuss such things so I will try to keep my future posts polite and on topic.

Regards
Thing