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VAWT Lenz type. Stage 1. Converting wind power to rotary motion.

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Update April 2012

The first and foremost  thing I must to say is that Edwin Lenz deserves every single bit of credit for this turbine design. check out his website below, this build was based on his designs although I added my own outside the box style thinking to the build design and use of unconventional materials.  The wings are basically exactly to Edwin Lenz design specs, with a sign design change to suit the materials I used.

http://www.windstuffnow.com/main/vawt.htm


I just discovered that the Intro Page has gone missing so I'm doing my best to re write it from memory, plus I want to tell how it has stood up to the weather over the last 3 years and what I would have changed if i was doing it again.

This was built to see how this new unique design compared to various vertical turbines, squirrels cages and savonious types just created to much drag at one side that just lost way too much power leaing you with very little torque.

The Lenz turbine on the other hand produced unbelievable torque, so much that I was unable to stop the axle from turning by gripping the axle with both hand while wearing welding gauntlets i just managed to slow it down, and on one occasion almost got a concussion as i demonstrated how much torque it had

This project was started mid 2009 a continuation of a failed squirrel cage turbine based on a design by Dan Rojas of greenpowersience on YouTube. 

At the time I had limited tools and a very limited budget for material and was trying to think outside the box as to what materials could be used.

Unfortunately as a power producing unit its just now up to the challenge and the hash winter of 2010/11 pushed the envelope on the plastic sign board and one of the wings developed a crack along the curve of the wing.

The plywood is still relatively sound 3 years on but is starting to show signs of de-laminating due to moisture penetrating the wood.  looking back in hind sight i would have coated the plywood with several coats of resin of some other very water resistant coating.

This design would work well in a warm dry climate, but unfortunately Ireland does not have such weather. the plastic skins on the wings became brittle and split along the tightest part of the curve on the wing in a freak cold spell last year when it reached -20*c, cold enough to snap a spring in my car in 2 places when I discovered a speed hump hidden in the snow.

The rolling design on the stand unfortunately resulted in me engineering myself into a few problems that would have called for a rebuild of the stand, this with a combination of health problems the project sort of dwindled out and finally got moved to a new position right out of the wind and has remained tied up since the skin on one of the wings split.  At this point in time the project was shelved due to health problems from old injuries that started to really catch up on my as reached the age of 40, but thankfully I am on the mend and turbine projects are no back on the menu as I now have a fellow turbine enthusiast who is much less skeptical of the Lenz Turbine once he saw it flying in the slightest of breeze.

looking back at the design I would have skinned the wing with metal sheet either aluminium or galvanized steel, it increase in weight would not be a problem as it add to the flywheel affect and help even out the drops in speed when the wind is blowing in gusts. the bearings where rated for 25kg weight would have been able to cope with the additional weight.

Design wise i would have changed the following things if i had to do this again. 

I would have gone with a single hub much like the picture that Slezridr posted below ( I have featured his comment) the double hub with and axle between the two using unconventional materials not best suited for my climate made it difficult to get perfectly true and the turbine has a slight tremor when spinning at high speeds.

I would have used allot more sealant and way more waterproofing as the plywood eventually started to get saturated with moisture and the glue starts to leach out and the layers start to de-laminate.
 
The the vertical axle design made it difficult to harness power without the use of belts of chains (chains do mot like to be mounted on a horizontal axis) 

I would have not used plywood and plastic sewer pipe for the hubs and central support axle, I would have gone with metal hubs and a metal axle, My skills with wood at the time of this build was not the best and I feel that i was really pushing the envelope as to the limitations of plywood and plastic, remember this turbine wieghs aout 20kg and can spin at 120rpm, no wonder my 80+ year old parents where concerned about it shaking its self apart.

Over all the build was a success, I am totally sold on the idea of these turbines and will never go back to horizontal or any other type of VAWT.  The torque thee turbines produce is just astounding, and yet they are silent and work perfectly with the wind coming from any direction.  They seem to have an upper speed limit of about 120 rpm at which point they go into an auto stall so you dont have to worry aout it spinning out of control on a stormy day, I read somewhere that winds needed to destroy one of thee turbines would the kind that would rip the roof of the house first.  Also they have no need for a large tower and seem to work perfectly at round level, I had my turbine located in the sweet spot between 2 buildings that created a wind tunnel affect as the air bunched up on the buildings to get through the gap. the bonus of haveing a turbine ar almost ground level means you can work at it and maintain it without the need to climb a tower to grease bearings and do maintenance.

My health is now thankfully starting to improve so I am again starting to scribble new designs for a complete rebuild.  The next turbine will be built to a much higher standard as I a much better range of tools and access to a wider range of specialist tools and have also found a source for better quality materials at almost scrap prices.

Although this project has now passed the point where it can be redesigned to produce power, I may have found a possible home for it and it may yet be able to serve another purpose with some slight modifications. so you never know so watch my profile and you may see it being put to a new use.

Thanks for looking I hope you find this Ible a useful reference on your own turbine build.


Please visit Edwin Lenz website http://www.windstuffnow.com/main/vawt.htm
 
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Dr Qui,
This is one of the best 'ables that I've read. Seriously, thank you.

Do you have data on torque/rpm over usable power generation?
Dr Qui (author)  sgtjasonshrout6 months ago

Today the 23rd of june 2014 the VAWT has been broken up due to the plywood de-laminating also the plastic skin became brittle and cracked. the base will be reused hopfully for another wind project. As a experiment in wind power the project worked well but the materials used where not as durable as I would have liked.

Slezridr2 years ago
OK, hopefully, here's my pics. Sorry.
IMG_0353.JPGIMG_0354.JPG
jj.inc3 years ago
I like these airfoil style ones, and I saw this
http://www.fastfurnishings.com/ProductDetails.asp?ProductCode=UGE_UGE-4K
and if you look at it from the below image, it has small airfoils like this, although they have a curve, I wondered if that twisted design is really any different from this.
StCanna jj.inc2 years ago
I tried the link you posted here but the product is no longer listed. Do you have any other links of an example of what you are referring to so i can have a reference?
jj.inc StCanna2 years ago
http://www.bettergeneration.co.uk/images/stories/jreviews/210_turby247_1239968771.jpg
Dr Qui (author)  jj.inc3 years ago
To be honest I don't know what the difference between the helix shaped airfoils would be.

I had to contact Edwin Lenz by email to check if my theory on what was happening with this type of turbine, thankfully I was correct in my assumption of how it works.

In the Lenz type the blade with the curve facing into the wind (the right side as you look at it) produces lift / torque,  as it rotates around the open back or the airfoil acts like the cup on a savonous turbine and is pushed around producing more torque,  and when wing travels through the back segment of the circle it acts in much the same way as how a sail boat woks tacking in the wind and produces some more torque before repeating the cycle.

In a word the Lenz type has all 3 wings producing power / torque almost constantly as they rotate. I did not fully understand the principle until I saw my turbine running,

The helix shape on the small airfoil blades does help, but I would have difficulty explaining it without seeing one running up close.
jj.inc Dr Qui3 years ago
Thanks
rimar20002 years ago
WOW! This is an awesome project.

Do not greatly improve the efficiency of a VAWT if it had a screen in front of the "negative" movement?

That is, a screen attached to a tail that prevent the wind hiting on the blades that move against it
Dr Qui (author)  rimar20002 years ago
Both sides of the turbine give power the right side acts like a wing and gives lift, the left side acts like a cup and catches the wind and pushes, the wing at the back acts like a sail boat tacking in the wind.

I emailed Edd Lenz re the theory to make sure i understood it and he said that my theory was correct. These there the turbine of the future, safe silent and slow and they go into auto stall at about 120 rpm and just don't seem to spin any faster.

Ambos lados de la turbina de dar poder a los actos del lado derecho como una vela y da ascensor, al lado izquierdo actúa como una taza y atrapa el viento y la empuja, el ala en los actos posteriores, como un barco de vela en el viento viradas.

Envié un correo electrónico Edd Lenz re la teoría para asegurarse de que me entiende y me dijo que mi teoría era correcta. Estos se la turbina del futuro, seguro silencioso y lento y entran en parada automática en alrededor de 120 rpm y simplemente no parecen girar más rápido.

Thanks for the explain!
Slezridr2 years ago
Excellent job! I also was impressed with the "Lenz Turbine" and threw together a prototype along the same dimensions as Ed's, 4' high and about 1-1/2' in dia. I wanted to avoid two hubs so went with a single trailer hub mounted to the center rib. Am quite pleased with the performance so far, though have some modifications in mind.

Like maybe replace the plywood ribs with ribs cut from nylon cutting boards. Maybe the stiffeners too. Weather resistant and can still use wood or sheet metal screws.

The intent is to make a dual rotor axial flux alternator based on windstuffnow's web site. I agree, very good informative site.

I hope my images loaded.

Again, good job, keep it up.
Dr Qui (author)  Slezridr2 years ago
I like the nylon cutting broad idea, i got some plastic off cuts from a place that makes various plastic things from car boot liners and bog boxes to the big plastic ice cream cones you see outside ice cream shops. unfortunately the guy who could have given me price quotes for the 1/4 and 1/2 sheets of 3/4 cutting board, i was limited to having out in one fre roam in the recycling bins and got as much stuff as I could carry out in one go for £5 i got some mice 12mm stuff but i found that was not as nice to work as the cutting boards, it tended to be very easy to melt the plastic when you drilled holes in it and they would always be over size no mater how easy you took it with the drill
Dr Qui (author)  Slezridr2 years ago
Nice build btw, can I ask where you seriously impressed with the torque these thing produce when  you first get it to catch wind. Seriously hypnotic you could stand and watch these for just way to long.

My next rebuild will most likely be an all aluminium and smaller maybe 2 foot by 2 foot as my folks where starting to show concern when it started to hit its max speed and goes into a sort of auto stall which was kinda scary cause of the shear size of it and the lack of load on it.

definitely going with the hub in the center like yours next time with added tension struts I got the idea from a small size chinese made VAWT i saw on youtube.

What part of the world you in, I see snow an i have to tell you that last winters real cold snap of well below -10*c cracked the plastic i used and the plywood is badly un-laminating.

It would be a sound enough job in a warm dry climate but for wet and cold plywood and plastic is a rebuild job about every 18 month I you are lucky.

Good luck in your work, keep the faith in the Lenz turbine and keep in touch
Slezridr Dr Qui2 years ago
I know what you mean, when the wind blows, I like to peek out the window and watch it turn. It looks faster than it actually is. I think I got about 120 rpm at best so far.

Winters are a challeng here in N. Lower Mi (US). I prefer sweating under the sun to chattering teeth in winter.

I initially started with Savonius type, but there again that required a robust frame with upper and lower bearing points. Not good if you want to get the unit up into the wind. I like the drag/lift properties of the Lenz turbine. I used aluminum flashing for the skin and introduced a slight curve at the trailing edgefor a little more kick by rolling around a length of pipe.

I also added wires from bucket to bucket at the top to control any oscillation that might occur as the buckets are not ballanced well (see photo). You can kind of see them in the previous photo, but this shows them better.

Again, good job and good luck.
IMG_0355.JPG
Dr Qui (author)  Slezridr2 years ago
To get an accurate reading simple paint a white spot on one blade big enough to see when is spinning and the you can either count with a stop watch or possible record a 1 min video of it that you can slow down to watch.

I used a 2" vinal sticker in red on mine.

Hope that helps with your stats

if i can find the Chinese built HAWT ill again ill post a link as its strengthening strut design is so simple yet seriously impressive i will be copying the design when i get back to mine.

cheers,

Andy.
Dr Qui (author)  Slezridr2 years ago
120rpm seems to be the upper limit of a Lenz type, I was maxing out at about around the 120 rpm at this point they just go into auto stall as Edwin Lenz puts it. I love the fact that it will max out at ground level and has no need fro a tower.

Ed Lenz is a seriously nice guy to actually make this stuff open source, and does answer you if you contact him with questions about it. I actually feel a bid bad that my instructable is 2nd on the list when you Google Lenz Turbine now, I have to give him the credit for what i did from his concept, and i am hooked on this type.

I even managed to convert 2 people who where in the HAWT camp, and the turbine drew so much interest from all who saw it when it was running, even the post man stopped and had a chat about it and the theory behind it.

My health has been improving of late and even better I have a few quid to spare for the better quality materials and i know a local firm where i can get aluminium cuttings large enough to be usable from thier scrap bin at scrap prices, They also have a water jet and i just have to find out what file type they need me to bring them to cut the fins with.

S with hope i might actually get to the stage where I can charge a battery even if i is a smallish one.
gfry3 years ago
Great turbine Doc! I have a couple questions/comments to throw into the fray. Have you considered a flexible drive shaft for the power take off on the turbine? They can be purchased assembled (expensive) or put together with some wire rope and aluminum conduit. Using this will allow you to mount your genny horizontally and away from the turbine. Secondly, has anyone tried to use a DC motor from a rechargeable lawnmower as the genny for a vawt. These lawn mowers are starting to show up at curb side on garbage days, I have "picked" a couple of them up and the motors are fine...its just the electronics that are shot.
Thoughts??

cheers
Dr Qui (author)  gfry3 years ago
Thanks for the comment,

Ideally the motor you use should be in line with the vertical shaft.

Any DC motor will work as an alternator, its just hard to find one that will produce a decent amount of power at low rpm. DC motors give better results in horizontal turbines but then you have the noise and risk of exploding blades to consider.

I have been in contact with Edwin Lenz and he recommends building an axial flux alternator for the best results.

Sadly my turbine did not winter well, we had a couple of weeks where it dropped to -20*C and one of the plastic skins cracked.  Also 1 year on from building the plywood is starting to show signs of delamination which is not good.

I hope to do a rebuild this summer all being well using more durable materials,  This project is really long term as I suffer from conic pains which are agrivated by cold, wet and low pressure weather, so I only have the summer months to work on this as well as try and do all the other stuff I need to do, but mussen't grumble.

To be honest the turbine part is the easiest thing to do in the overall project, its matching a motor or generator to it is when it starts to get complicated.  The electronics required for the battery bank needed to store the power you generate is the hard part, and is the stage I am not looking forward to one bit.

If you build something please post an Ible as I would like to see what your slant on things are.
gfry Dr Qui3 years ago
I have been itching to get into one of these things for a couple years now, and I have finally started getting parts together for it. I will be doing something over the next few months...something like windspire.com...they have an interesting take on it. I am researching the Aerofoil blade construction now. I have seen the lenz turbine b4 but it seems a bit cumbersome and likely prone to breakdown in high winds. I have some 3/4 inch ABS flat plastic stock that I will make the ribs out of, and I intend to wrap the blade completely with a light gauge galvanized sheet metal. The blades will be symmetrical with an offset.

The reason I suggest the flexible shaft power take off is that it will allow me to put my generator in my basement. I am running the pole for the turbine up the side of my house, but I want all the electronics indoors. I will run a 3/8th cable through aluminum conduit down the center of the support pole, and then through my basement wall into my work room where it will hook up to my generator.
I picked up a used 3500 watt Honda clone generator for 50 bucks. The motor is shot in it but all the electronics and genny work fine. That might be an option for you too if you are dreading the electrical end of your project.

Anyhow, I will photo the process as I am assembling and see if i can't put my first ibble together. Oh...and I am using deep cycle batteries that have been discarded by local marinas. (freeeeee) I picked up a desulphator and installed it in my car. It takes 3 weeks to a month to get the batteries back into condition with regular driving. I have 6 batteries in good condition now after 10 attempts.

Cheers
TDIMark3 years ago
Many thanks for sharing this! Your project convinced me to get the Pro subscription. When will Stage 2 be appearing? BTW, I'd buy a book from you on this if you are so inclined.
Dr Qui (author)  TDIMark3 years ago
Thank Edwin Lenz, its his design.
http://www.windstuffnow.com/main/lenz2_turbine.htm
thalass4 years ago
Awesome turbine. I'll watch this with interest as i'm going to convert a bike to electric power soon and having a backup power source would be great.
Dr Qui (author)  thalass4 years ago
It's not awesome, it's blue.

I have never been struck by a sense of awe when looking at this.

I have been struck by one of the blades when oiling the bearings.

Don't hold your breath watching this, 2011 will see another rebuild



thalass Dr Qui4 years ago
Hah. Well, i'll keep an eye out anyway to see how you go.
dulciquilt4 years ago
We have a 4 wheeled recumbent bike http://blackbirdbikes.com/ with one hub motor (so far). This motor is 24v but we hope to get a second one that is 36v. Would it be possible to make a turbine small enough to mount on the cargo platform so it would charge the battery as we rode bike?
We've also been considering making one for our RV as some of the places we go don't have elec and the generator uses a lot of gas.
You need to consider the increase in drag that the turbine will generate. This will in turn drain your battery quicker. Without an extremely efficient turbine generator, the increased charge will be largely negated by this increase in drag. It's possible the only time you'll benefit is when the bike is stationary.
Dr Qui (author)  mwotton4 years ago
WRONG,

http://www.youtube.com/watch?v=DPvGTjmn9y0
Dr Qui (author)  dulciquilt4 years ago
If i had a wheeled platform i would hook my turbine directly to the chain drive system, getting the gearing right would be the problem but i do think it would work as my turbine averages about 50-60 rpm with reasonable torque just about the normal curiousness rpm of a bikes cranks.

I have discussed the idea of mounting a VAWT in a small boat and useing it to drive a propeller.

Check out reukpower and his Lenz turbine Ible, is a nice size turbine to start out with.

For your idea of a turbine for your RV  a HAWT will be easier to build
or even maybe buy, but will be much noisier and prone to damage in sudden storms. a VAWT is a bit harder to figure out and build but is silent and is not prone to damage by high winds and it also can be ground standing.

good luck with your project.

It is possible to build and fit one in the cargo platform, but the charging is going to be small (trickle charge). So if the majority of power is going to be pedaling, then it will charge the battery slowly. Once the Motor starts running, then it will stop charging.

For the RV, you can look up this Turbine Instructable; it can be built to charge at 12V or 24V. You can also use the design to build a smaller version for the recumbent bike as well.

Hope this helps!
Thanks for the info. I passed it on to my hubby.
perfo4 years ago
Good looking VAWT. I'd be interested to find out what performance you get out of it. Just as a thought have you considered using a car axle as the shaft and bearings? Using half of a car rear axle will give you the strength and rigidity and if you feel extra inventive you can leave the hub and brake assembly attached with a hand brake outside the throw of the blades in case you ever need to stop it in a high wind or simply stop it moving if you want to reposition it.
Dr Qui (author)  perfo4 years ago
Thanks, its all based on Ed Lenz work so he deserves the credit.

I have though of using a wheel hub assembly to mount the turbine on, to be honest i recon this will get a rebuild in the spring time, better bearings and sheet aluminium blades as the climate here is a bit on the damp side and the plywood just aint up to it and would need rebuilt every few years.

I really have to bring my working knowledge of the electronic side of things up to speed before this project  continues. catching the wind is no problem, the tricky bit is when all the other variables come into play like finding the right motor that will match the turbine.

Performance wise I am totally sold on the Lenz type.  It runs silently and in high winds it reaches it max speed and then a stall effect kicks in and it just wont over run.  It has a vast increase in torque than the squirrel cage turbine I built , its hard to explain but all 3 blades seem to be catching the wind almost all the time.
Very nice. Thank you for posting. I am looking forward to your stage 2 posting.
Dr Qui (author)  earthwindwater4 years ago
Thanks, might be a while until stage 2, winter is hear and i go other things to do first before i can continue.

I'm working on a Large Stirling engine to run on the heat from my wood stove at the moment along with a few other projects. the wind turbine wil be picked up in the spring time when it gets warmer.

stage 2 will probably be to replace the wooden hubs and the plastic pipe and replacing them with metal ones, I think the plywood is starting to be delaminating as the is a bit of what looks like glue seeping out at certain points.  I think i can use 2 of the aluminium castings i used in my pvc pipe HAWT ible.

jayjayec4 years ago
does it matter which direction the wind is coming from? sorry i know it's a dum question but im new to wind turbines and trying to deside if i should to build this design or a double helix design
Dr Qui (author)  jayjayec4 years ago
Nope, it works with wind coming from any direction.

This design has much more torque than my last one, The Lenz type is difficult to explain, but once you see it running its starts to make sense.  

I'm new to this type of stuff too, but this is by far the best type of VAWT, we recently had quite high winds and the turbine showed no sign of damage.  The Lenz type seems to reach a top speed of about 200 rpm with no load and then just don't seem to get fast no mater how strong the wind gets.

My project is is a holding pattern at the moment while I try and get my workshop kitted out with better equipment.  what you see is about 18 months of tinkering, I have found that the turbine bit is the easy part of the overall project,  Its matching up a suitable alternator that is the difficult bit.

I have plans to build my own alternator on the motot shaft of an old angle grinder head, the grinder has a 4 to 1 ratio 90* gear box that should give me better rpm.  I try to use as much pre fabricated componants as possible as it surprising how many industry standard parts scavenged from junk can save you so much time and effort.

Good luck with your build, look forward to seeing an Ible.


I build a savanious wind turbine in 1980 it was made using plywood and aluminum rotors (aluminum flanged pipe section cut in half three tires off set my bearing where combine bearing dodge brand and my frame was welded tubular steel . I had same plans to run a generator charging couple 12 volt batteries. now a days i's recomend the rare earth generator in the 500 dollar three blade turbine horzontal axis (worlds best selling wind turbine) you can get the generator seperate. My plan was to use gear belt pullys and i bought those for ninty dollars and never used them. the ninty degree angelgrinder is great idea direct coupled to the aformentioned alternator. Oh if I just had perfect recall. anyway good job on this one. I'd look at all aluminum myself because after four years in weather my plywood started de-laminating. another thought will be seperate kk
Dr Qui (author)  rapidprototyping4 years ago
I painted my wooden parts with a standard hard gloss paint, A friend of mine had been to meet Hugh Piggot and picked this tip p from him., he says exterior gloss paint is as good as any as long as you take your time and do a good job and several coats.

I too had problems with the first turbine de-laminating, this time i made sure it was well painted and should last a good few years if i keep it looked after.

I have an idea for a HAWT made completely from a scrap washing machine and will be posting the results of that soon. There are high grade components that a perfect, there is even a monopole motor on the water pump that will produce power.  I have the concept in my head and now just need to do it.
this is my third try at getting these photos to you so you can visualize what i have suggested . there another cat building a generator his design looks pretty good but he is putting it on a horzontal axis wind turbune. it's similar to the pancake motor design below using permanent magnets. i like that for making the turbine float in a light breeze turn easier. the concept of having the generator intergrel to the bottom or top rotor is good concept as well. taking your time and following suggestions is important as well realize i've been there done that. learned from my mistakes as well this savanious ran for years in the lightest of breezes but never generated any electricity at all I would gladly give it another try if had the right generator to start with.neodynium generators are STATE OF THE ART GENERATORS
Savinous Wind Turbine.jpg1980.jpgPancake Motor (how it works).jpg
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