Lenz Turbine

[PeterDove]

Hi All,

Just made my first turbine using the plans from the Lenz Turbine. Its made from cardboard at the moment just as a test. It spins very nicely in winds of 10mph. I do have a couple of questions about it and other related matters. I am a complete newbie at this so please forgive the dumb questions

1. What is the best ratio between the height of the lenz turbine and it diameter?
   
2. What sort of winds should it self start in?
   
3. Are there any new discoveries with the Lenz? Any improvements I can make.
   
4. I am having trouble understanding/sourcing some kind of turntable system with minimal friction for the contraption to turn on.. Is there any kind of standard setup for vertical wind turbines?
   
   

I have had a good look on the forums and seen some good discussions on lenz design, but still am missing a few items which would get me on the right path.

Thanks all.

Peter

[windstuffnow]

  Pete,

    I couldn't say for sure what the optimum aspect ratio would be, I've built them 1:1 2:1 and 3:1 they all seemed to perform well.

    I have no real idea of what wind it will self start in.   My roof top runs in winds that won't turn the anemometer... no way to measure it.  I did have a test unit out the other day and according to my hand held unit it was turning in a .7 mph wind, all be it very very slowly. It needs 5 rpm to start charging and wasn't even close.  The small ones, however, seem to have a bit of a diffucult time starting.   Someone had told me this and I couldn't imagine what the difference might be and built one.   Sure enough it was a real dog.   The small ones need a different wing angle to start and run well.  I built a tiny one, 8 inches in diameter and 1ft tall.  Played with it for quite a while getting it to run right.  Anyway, the small units need a wing angle of 0.  Also, you want to make sure the bearings are easy rollers, there isn't much power in the small ones until the wind gets going.   The 8x12 in a 10mph wind will only do just over a watt, bearings that have stiff grease in them will absorb most of that watt.  Carefully pry off the rubber seal and clean the grease out with kerosene, lubricate them with some 3n1 oil or other light oil and it will scream! (poke the seal back in of course ).

Yea, there are some new developments but I'm not inclined to mention them as yet.  The original L2 version works very well.  The new one is a little better and the cut in speeds are rediculously low.

I've mounted them on top of a bearing structure leaving the entire turbine above, a central mount and in a cage ( my roof top ).  I'm partial to the central mount although the roof top has been trouble free.  I don't know how much of the air is disrupted with the tubing around it and it seems to perform very well.

Have Fun!

[nanotech]

Ed, something I was wondering about, aren't most of your VAWT's about a meter in diameter?

If so, how would a 27" (ten speed style) bicycle wheel work as your top and bottom bearing?  Very light weight, very easy to turn, and very strong.  Also relatively easy to make a "ready rod" axle that goes through both wheels.....

If you've thought of this before and tried it, I couldn't find anything on a search.

[inode buddha]

I can't say much about the airfoils and such, but have you considered using the bearings from a swivel La-Z-Boy or "lazy susan" bearings? Not sealed at all, and they are usually shiped "dry" to larger home improvement stores in the USA.

[windstuffnow]

nanotech,

   I don't see any reason it wouldn't work.  It would take a little thought on mounting the wings to the rim but overall seems like a do-able idea.

   My roof top has 2 basic pillow block 1 inch bearings mounted to the side of a frame.   A little overkill but it works great.

.

[zapmk]

Hi Peter,

Welcome to the LVAWT's club.

I have been playing around with Ed's wings for awhile, the aspect ratio has been fun to play with.

The diameter is related to RPM and at the same time torque output, swing a bigger arm more torque, but slower RPM.

The height only seems to be related to torque output, seems to have no change or very little change in RPM.

The test stand I built has a top and bottom bearing, used flange type gokart ball bearing. it in my files, I have been building  one for a center mount, no frame,  needs to have very strong arms and bearing supports, the bigger you build it the stronger it needs to be.

Question for Ed.

Ed, it starts charging at 5 RPM ?

 -Zapmk

[windstuffnow]

  Yea, isn't that simply crazy?  If its spinning its charging.  Pretty low output at that speed though, about 30ma into a 12v battery.

.

[Bruce S]

Hello Peter;

   I have luck using the bearing from old inline skates. They are already nice and easy to turn and somewhat weather proof.

Bruce S

[electrondady1]

ed, can you give a quick rundown of the geni your using . i guess it's the eight inch set up, 12/9 ?   what sort of turns and wire gauge?    

[windstuffnow]

  It's an 8 inch 12/9 layout.  1/4" thick stator.  0.4 ohm resistance. #18 wire.   Mounted on an 8.125 sq ft turbine 30" diameter 39" tall.  Actually I have accumulated quite a stack of stators experimenting with it.  I've been tossing around the idea of having a "cyber garage sale" to reduce my clutter, including the blade duplicator that I don't use anymore.

.

[lohearth]

 Ed

 I noticed from the pics on your site that you live on a farm. Have you ever considered making a big vawt from old farm equipment. Thought about all the parts that can be used from an old combine (McCormick). Alot of good heavy duty parts available from equipment that is now slowly rusting away. Been on my mind since I sold my farm 20+ years ago. Just a thought

  Lohearth  

 

[Bruce S]

Ed;

   give me a few days to turn in the Aluminimum cans so I can have some pennies saved up for the garage sale :--))

Bruce S

[electrondady1]

it's a great moment in vawt history ed when your blade duplicator became obsolete.

cyber yard sale at your place ? ok !!

maybe just a new link on your sight.

[wooferhound]

I don't think the bearings on a bicycle tire are made to take the force sideways for very long. The weight of your turbine would kill it after a while.

[ghurd]

I have a whole new respect for bike bearings, after trying to machine some just a little bit.  I have a feeling they can take a lot, if kept from rusting.

G-

[nothing to lose]

Drop me an e-mail when you have that yard sale, I don't want to miss it!

I just bought 2 draw knives, but I could still use a duplicator like yours.

Since we're on the subject of the Lenz and Lenz2, I think you used aluminum sheet for your wings, do you think sheet metal will be to heavy for mine? I haven't got any aluminum sheet, but I am scraping out a couple cars and have lots of nearly flat roof and hood sheet metal.

 I built one, but I did not do a good job on it. Either off centered or very bad balance problem, it turned decent I geuss but shook like an earthquake. Good design, faulty parts/workmanship on my part though. I reshaped plastic barrel sections for the leading edge and I think that was the problem.

[lohearth]

 I wonder how well the bearing from the handle bar neck would work as a thrust bearing and use a set up like Stonebrain uses (bearing/thrust bearing combo)?

[ghurd]

I think they are the best thing in the whole bike.

(dimpling is a lub failure and only happens on road bikes)

Too bad I can't figure out how to actually use them with the tooling I have.

I had a decent windmil designed around it. No welding, etc.

Can't get other stuff to fit the bike stuff.

G-