Author Topic: Lenz 2.4 (Read 13446 times)

windstuffnow · « **on:** April 28, 2006, 02:41:56 AM »

This is the next generation of the Lenz 2 Turbine nearing completion... a little bit bigger. It's 4.5ft in diameter and 8ft tall. The picture below shows the wing completed...

Next is the wings standing in their positions...

Lastly the center structure...

The ribs are fiberglass reinforced plastic, the stringers are aluminum and the skin is .020 aluminum.

Its getting close for some testing...

.

willib · « **Reply #1 on:** April 27, 2006, 09:21:17 PM »

hmmm someone's been busy..

ed somebody installed a red cabinet inside your turbine

zapmk · « **Reply #2 on:** April 27, 2006, 09:52:10 PM »

Nice looking wings, looks to be very light weight.

Hmm, looks like maybe a design change to the nose ?

What no end caps ?

Be interesting to see what the design of the Alt. these puppy's are going

to drive.

Keep the post coming, You have me seating on the edge of my seat.

-Zapmk

oztules · « **Reply #3 on:** April 28, 2006, 12:42:46 AM »

Envy is one of the worst human traits...........and I'm full of it!

I'ts marvellous to see a new idea coming to fruition.

Even if it doesn't set the world alight, with it's performance (and we all hope it does) it certainly stirs the imagination.( although it may cause some folks to topple over the edge into the afterlife when they see airfoils made out of that beautiful Aluminium.)

I had nothing to do with the building of it, have no idea how it will work,....but somehow I feel very proud of it....... and it's not even mine (or on the same continent)

Beautiful work Ed

................oztules

electrondady1 · « **Reply #4 on:** April 28, 2006, 05:06:45 AM »

ed, what a tease ! ok, i'd like to know alot more about the construction of those plastic/fiber glass ribs !.also ,these photos imply you are going with a single central bearing, thats gutsy.

electrondady1 · « **Reply #5 on:** April 28, 2006, 06:02:58 AM »

well, curiosity may have killed the cat but when can i get a peek at these"winglets " your have mentioned. and the big question of course, what's the dia. of your mag rotors gonna be ? 8"?

nothing to lose · « **Reply #6 on:** April 28, 2006, 06:57:53 AM »

I have been watching for a new posting or update on the Lenz2 for along time and wondering what was up or where it went.

WOW, it grew

This looks great as most of your stuff usually does. Still while waiting for more info and for it to fly, have you been flying the Lenz2 and have any more info posted on it?

Good luck with the Lenz 2.4 I expect it should make alot of power.

windstuffnow · « **Reply #7 on:** April 28, 2006, 08:29:04 AM »

I started making them out of aluminum sheet similar to Tom in NH built his. After making a couple of them they seemed a bit flimbsy for what I needed for strength, although extreemly light weight. I decided to make one from wood and cast it and test the strength. Below shows the wood rib laid in a mold...

Fill it with liquid rubber...

Take the mold apart, pull the wood rib out, fill it with fiberglass and pour the plastic...

Takes 15-20 minutes for the plastic to harden then pull them from the mold and start over...

I like working with the liquid plastics, I've found tons of uses for it from making replacement parts for things that break and even making up set of gears....

kitno455 · « **Reply #8 on:** April 28, 2006, 11:40:45 AM »

great looking. i remember you saying the smaller ones were 'touchy' about angles. do you feel you have that squared away enough to build such a big one?

also- i am surprised you went with only the single center support. i would have suggested two, at ~ 30 and 70 % of height...

allan

windstuffnow · « **Reply #9 on:** April 28, 2006, 12:29:37 PM »

I put a considerable amount of thought into it as well as calculating the loads leaving 4ft on each end of the arm. The half tube structure is quite strong, similar to an I beam. It basically can't move forward or back ( bending ) because of the large area of sheet tied into the trailing edge structure. The in and out bending forces are controlled by the I beam structure. Also, what you see in the picture isn't the completed wing structure. The top and bottom will have struts going from wing to wing. This way any bending force on one wing will be transfered to the 2 others. This does allow a considerable amount of force the central pivot point has to endure but mostly in turbulant winds where it may load the turbine above or below the pivot. I highly doubt it will ever reach its 2000 lb rating. If we get a storm that will exceed that rating, the turbine will be the last thing I'll be worried about.

.

hvirtane · « **Reply #10 on:** April 28, 2006, 12:38:15 PM »

Looks very very good.

When is the time to test?

- Hannu

kitno455 · « **Reply #11 on:** April 28, 2006, 12:42:51 PM »

the top and bottom triangle struts will help considerably with the rigidity of the prop itself, but i would still be worried about how close your upper and lower bearings will be to one another, on either side of that center plate. but, i as a rule, like widely spaced bearings.

allan

vawtman · « **Reply #12 on:** April 28, 2006, 03:01:53 PM »

Nice job as always Ed.I think youll get 4 times the power.What about adding supports to the blade ends if possible?Things can get nasty when the blades are increased.The difference between the smaller Lenz and this one should surprise you.Good luck and have more fun.

electrondady1 · « **Reply #13 on:** April 28, 2006, 07:30:05 PM »

thats a very nice casting technique on the ribs ed, thanks. and of course, if you stick with this size of vane on future mills it will be all ready to use again. did you cut the glass cloth into strips ? and then fill the cavity?. what sort of resin?

thanks for clearing up the mystery of winglets on the other post. for some reason i thought they were some kind of exotic formula 1 type thingie that ran verticaly on the vane edges . doh!

im thinking ,by keeping the same dia mill and doubling the lengh you double the torque so you can run a larger load.

windstuffnow · « **Reply #14 on:** April 28, 2006, 07:52:03 PM »

Actually, I have one more in mind. I'd like to build an 12ft diameter version about 16f tall to install on my 45ft silo. Not this year though, my summer list is still about 2 summers long...

The cavity of the mold had strips laid in so it formed a C then the plastic was poured. The plastic is the fast setting 300 series at http://www.smoothon.com . You basically have 3 minutes from mix to completed pour otherwise you have a cup of hard plastic. They have slower acting but the de-mold time is also much higher.

.

electrondady1 · « **Reply #15 on:** April 28, 2006, 08:38:07 PM »

that's exciting news ed. i remember you and i have discused this earlyer a bit . i think a silo is a perfect platform for a big vawt. i'm thinking i should be moving to an old farm house soon. perhaps you might do two more mills if you build on the big silo as well.

electrondady1 · « **Reply #16 on:** April 28, 2006, 09:18:48 PM »

ed i've never used the liquid rubber material before what do you recomend as a parting agent? do you need to put a parting angle on the original ?

windstuffnow · « **Reply #17 on:** April 28, 2006, 10:29:58 PM »

I use a spray on for molds I plan to make lots of parts with but I didn't use any for the ribs. I use the stuff called "OOmoo25 or 30" its a 1 to 1 mix by volumn. Don't get the other stuff that is measured by weight, It takes to long to set and I've wasted alot of the stuff because I didn't get it mixed right. I think the 25 is fast setting, hour? and the 30 is a 4 hour cure. I like the fast stuff, when I get an idea I want to see it finished asap! The rubber is kind of expensive but it makes a considerable amount of molds depending on the size of course. I mostly make small parts so it lasts a good long time. I get about 75 to 100 parts from each mold as long as you use a release agent every 10 parts or so it does quite nicely. Toward the end the rubber dries out from the heat of the plastic curing and you'll see some breaks or deformations in the mold. I really like the stuff, it's quit fun to work with.

.

stevesteve · « **Reply #18 on:** April 29, 2006, 01:45:49 AM »

Ed,

I too wondered about the twisting moments that the blades might impose on that centre strut. I notice Tom has put a second brace at the top but you are going to brace from one wing to another.

Inspirational work. Please can you get a movie clip posted as soon as you get it spinning?

willib · « **Reply #19 on:** April 29, 2006, 07:24:44 AM »

ed thanks for the link ..

that liquid plastic stuff could come in handy ..

how hard is it when cured?

iFred · « **Reply #20 on:** April 29, 2006, 10:57:17 PM »

Hi Ed!

Breaking the limits of imagination as always! You never cease to amaze! Following your progress; you have built a small unit, done the calculations, re-build a wind tunnel and done the wind tests, confirmed the data, built a large unit.... you are determined I'll give you that!!! I wish you the best in testing, and as always... please keep us all on the edge of our seats! Good Luck!

windstuffnow · « **Reply #21 on:** April 30, 2006, 11:20:05 AM »

Hi iFred thanks for the encouragement. Haven't heard much from you lately... I think your up to something ! Something quite interesting I'm sure.

Did you ever play around with the plastic stator I sent you? I should have made a mold for that, I have some odd ideas for it and need to make up another one fairly soon.

.

zapmk · « **Reply #22 on:** April 30, 2006, 09:57:02 PM »

Ed,

I have a 2 part question for you.

My Wife makes concrete stepping stones and small benches and she uses a chopped fiberglass in the concrete mix that she uses.

Do you think this chopped fiberglass would work with the plastic mix ?

And are you still using the fomula of Width of C = 1.875 X the diameter

and tail length = .4 X the diameter.

I know at one time you posted that you were working on another set of wings that would enhance the downwind capture and clean up the upwind side.

So has this fomula changed for the wings ?

-Zapmk

windstuffnow · « **Reply #23 on:** May 01, 2006, 08:53:19 AM »

Still the same formula... I haven't finished and tested the newer wings as yet, these work well enough to continue with them and as time allows other tests and changes will continue. I have to many irons in the fire right now...

.

Ungrounded Lightning Rod · « **Reply #24 on:** May 15, 2006, 08:51:42 PM »

Just a thought, if furling is ever needed:

If the rotor's efficiency is strongly affected by small changes in angle, the mill might be furled by allowing the blades to pivot slightly and go out-of-tweak when they start spinning too fast.

And you could make it automatic by adding a linkage so they all go at the same angle to preseve balance, a stop at the efficient angle, and a spring to hold them against the stop until the forces (centripital, wind) are high enough to lift them off the stop against the spring's force.

cr8zy1van · « **Reply #25 on:** August 17, 2006, 04:24:43 PM »

I have been watching your development of the Lenz machines for some while now and cant wait to see what your churn out next. I do have 2 questions for you if you dont mind.

I see that your wing ends are open, being made from the same ribs that you used in the rest of the construction. Would capping them make any difference?

During WWII plane wings were constructed from painted canvas. I know it probably wouldnt stand up forever but would a wooden/same plastic ribs as yours construction covered in canvas and painted with fiberglass resin work? Of course I would have to make a vertical member or two to keep the ribs in place. I am looking for something light, but know that I may have to sacrifice durability to get that.

Have you seen any numbers from your project? I have been on pins and needles since I saw this post, but have not noticed any updates recently.

Thanks again.

motoman465 · « **Reply #26 on:** October 19, 2006, 09:30:10 PM »

Hey Ed,

Any more progress with the Lenz 2.4. I was drooling when I first saw that post. I still drool when I look at it, but now I don't keep my head over the keyboard. You do some incredible work...keep it up!

Todd

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Author Topic: Lenz 2.4 (Read 13446 times)