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Forum Index : Windmills : Miller Rotor
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| RonS Newbie  Joined: 19/06/2007 Location: AustraliaPosts: 18 |
Some few years ago I was involved in helping people understand 'Miller Rotor' windmills which are a very powerful, 'torquey', non-aerodynamic way of extracting power from the wind. (Think: Holding a sheet of roofing iron and a wind blows up suddenly.) I was surprised to learn that no one on your forum had ever mentioned them. Miller was an elderly gent with an inventive bent who wanted to leave something to posterity of his own devising. He developed the Miller Rotor in conjunction with (I think) the Ballarat Tech, School some dedades ago, but died before he could complete all his research. The Tech published his incomplete work afterwards. I did a lot of models and few larger ones to determine what the optimum ratio of dimensions for the blades should be. People around here got used to 'that funny fella' driving around with outlandish contraptions strapped on the back of his ute when I was testing different ideas. What I came up with, finally, was a ratio of about 1:1.6. A sudden flash of inspiration made me realise that it should probably be the 'Golden Mean' of 1.618. I tried it and it WAS the optimum! Anyway, attached are a few pictures that should help you get started on this uniquely Australian invention. Yell out if you need help. Words of Warning ... These rotors are unbelievably powerful and will quite happily take off an arm, a head, etc. They have one saving grace, however, they always turn a quarter-turn backwards before they take off reaching full torque in one revolution or less. The bad news is, they start in very light airs (less than 1M/S) 
Avoid strong drink. It makes you shoot at tax collectors ...and miss. |
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vasi Guru  Joined: 23/03/2007 Location: RomaniaPosts: 1697 |
I think Lenz turbine is an evolved version of this "Miller Rotor". Hobbit name: Togo Toadfoot of Frogmorton Elvish name: Mablung Miriel Beyound Arduino Lang |
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| RonS Newbie Joined: 19/06/2007 Location: AustraliaPosts: 18 |
I don't know the Lenz Turbine, Vasi. Can you tell me something about it, please? RonS Avoid strong drink. It makes you shoot at tax collectors ...and miss. |
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| vasi Guru Joined: 23/03/2007 Location: RomaniaPosts: 1697 |
First, this link about "The Owner of this project". VAWT Lenz turbine Then, about Glenn Lenz turbine: Lenz on the sky :) If you digg on this forums you will find more interesting things. Hobbit name: Togo Toadfoot of Frogmorton Elvish name: Mablung Miriel Beyound Arduino Lang |
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vawtman Senior Member  Joined: 14/09/2006 Location: United StatesPosts: 146 |
In my early days i tested blades almost exactly like that with 8ft blades and it acted like a weathervane most of the time.I did get it to spin a couple times wasnt good stayed up 1 day. Conclusion was that not enough lift could be created from flat blade with just little curls on each end plus the curls cancelled out each other. You need more meat in them has i like to call it. Just from my hands on. |
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| RonS Newbie Joined: 19/06/2007 Location: AustraliaPosts: 18 |
More on the Miller Rotor ... First, it will only work with two blades. It is not a variation on the Lenz design, predating it by a couple of decades or so. The Miller Rotor is NON-aerodynamic in that it does not rely on venturi effects nor any other aerodynamic device. The Miller Rotor converts static pressure generated by the wind to torque. Best results are obtained if you use the proportions I gave (1 : 1.618), however, there seems to be some leeway available in this regard. This will impact on performance parameters negatively to the point of becoming a wind-vane, in some cases. With each blade comprising of three 3 metre sheets of corrugated roofing iron, suitably braced, a shaft power of 18HP was generated in a ten MPH breeze. (Roughly 13Kw at 4 m/sec). This was measured with the thing mounted on my ute which I couldn't get to accelerate beyond about twenty Km/Hr, even in first gear. The side forces during gusts on such a blade are frighteningly high so the tower has to be massively built for use in hilly areas where 'gully winds' may be present. Avoid strong drink. It makes you shoot at tax collectors ...and miss. |
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| vasi Guru Joined: 23/03/2007 Location: RomaniaPosts: 1697 |
Is better than Lenz turbine? It starts in low winds? Is not too heavy? The Lenz turbine can be scaled (and stretched  ) with no problems.Hobbit name: Togo Toadfoot of Frogmorton Elvish name: Mablung Miriel Beyound Arduino Lang |
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| vawtman Senior Member Joined: 14/09/2006 Location: United StatesPosts: 146 |
Ron Corrugated roofing? Now it seems to me your making it even worse. 
Static pressure into torque?
9 meter blades on ute(whatever that is)
Got a pic or better yet a video. Im lost Mark |
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Gill Senior Member Joined: 11/11/2006 Location: AustraliaPosts: 669 |
Vawtman, A ute is what we in Australia call a utility vehicle. I believe you yanks call them pick-up trucks. Don't know why, they seem much too heavy to pick up. he he. was working fine... til the smoke got out. Cheers Gill _Cairns, FNQ |
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Highlander Senior Member Joined: 03/10/2006 Location: AustraliaPosts: 266 |
By the way the ute was invented by a Ford worker in the Geelong plant, here in Victoria, Australia. 
The poor bugger never got a cent for his idea either.      
Typical. Central Victorian highlands |
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| vasi Guru Joined: 23/03/2007 Location: RomaniaPosts: 1697 |
Here is an e-UTE . Hobbit name: Togo Toadfoot of Frogmorton Elvish name: Mablung Miriel Beyound Arduino Lang |
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| vawtman Senior Member Joined: 14/09/2006 Location: United StatesPosts: 146 |
I thought it might have been a gigantic elephant of some sort. Thanks for clearing that up guys.  |
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| RonS Newbie Joined: 19/06/2007 Location: AustraliaPosts: 18 |
Vawtman ... The blades are 3 metres (not 9, as you stated). For the uninitiated 3 metres translates as 'about ten feet'. A standard sheet of corrugated roofing iron covers 762 mm (for you, two foot six, roughly) this gives a blade dimension, over-all, of about ten feet by seven foot six which is way outside the recommended ratio of dimensions but works all the same. If you want to go all pedantic, you might overlap the sheets a little more to better approximate 1:1.618. As for "static pressure into torque', try holding a sheet of something light but large, say a sheet of 8ft by 4ft plywood, at an angle to a stiff breeze. You will shortly appreciate what that means. As for a picture, have a look at the first post in this topic. I'll agree the tower asthetics leave something to be desired, but the basic thing is there to see, albeit in the form of a small demo version. This one is mounted on a small washing machine gear box which originally drove a small electric motor as a generator to light up an automotive light. (Dimly, I must admit!)  Avoid strong drink. It makes you shoot at tax collectors ...and miss. |
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| RonS Newbie Joined: 19/06/2007 Location: AustraliaPosts: 18 |
Yes Vasi ... It can be made very light if you have access to thin plywood and sheets of polystyrene foam, or similar. Just build a 'sandwich' of two sheets of light ply with foam as the filling all held together with marine-grade two-part resin. This is extremely strong. A 50mm foam core with 5mm plywood cladding can easily support 600Kg in the middle with each end supported on something strong. The thicker the core material, the stronger the result. The cladding has little effect on final strength values as long as it has good tensile (length-wise) strength. (D__n!! forgot all those CR/LF's again.) Avoid strong drink. It makes you shoot at tax collectors ...and miss. |
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Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344 |
Hiya RonS, Eh mate I like to keep the aussie tradition going so I reckon I might have to have a go with the miller.  I can get a warman spindle drive from work which will be perfect as a bearing hub (4" tapered bearings). When i get to scrap a big warman drive i intend to put 3 44 gallon drums on it as a big water pumper but thats down the track when I can get some decent scrap steel for the base, also the big warman drives weigh about 400 kg's, so yea it will need a solid base and about 2 ton of concrete to hold it down.
Cheers Bryan 
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| vawtman Senior Member Joined: 14/09/2006 Location: United StatesPosts: 146 |
Ron You stated"with each blade consisting of Three 3 meter sheets of corrugated roofing iron" and i took it has 9 meters sorry. On the static pressure into torque thingy.Sure the pressure will force it to turn but would seem to me that it would be jerky and slow rpm.Thats why most wind turbines have curved blades to break up this pressure and spin faster.A glancing blow if you will.Just my thoughts. Hey if it spins it makes power so keep going. How did this get so elongated? |
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| turnymf Regular Member  Joined: 04/10/2008 Location: AustraliaPosts: 84 |
Hi fellas I am looking for any data for the miller rotor I recently made a couple of models and was gob smacked by it's rotation and torque I expected it to stall, not start at all or spin unbalanced and jerk about This is not the case I have searched but there are few results via google So I am hunting for any info on the rotor or Miller himself Thanks in advance |
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| angus Newbie Joined: 08/12/2009 Location: AustraliaPosts: 7 |
RonS.. Gotta paraphrase your " avoid strong drink"-- It makes you miss when shooting at tax collectors. 
This may be of interest " www.wind-smile.com/" Regards Angus Angus.. (The older I get, the better I was). |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Wish I could help. I still have the little Miller rotor I built a couple of years ago, its still running. I agree, it has a lot of torgue and I suspect its TSR is over 1, making it a lift based VAWT. I agree the Miller rotor needs more research. I have a feeling it would be easier to make a Miller from some roof sheeting iron, than a Savinous from a cut up 44 gallon drum. And the Miller would give more power. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| Gizmo Admin Group Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
I just took this picture of my little Miller. Its driving a stepper motor, which powers a few LED's. The plastic icecream lid is to keep water off the stepper motor. 
Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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