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Forum Index : Windmills : Stall---pulse start?
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Rastus Guru  Joined: 29/10/2010 Location: AustraliaPosts: 301 |
Hi Bob,Bruce and DonB, Starting a stalled mill at a minimal wind speed is a tempting idea!The fact that Bob and Bruce have had some results with this in the past is promising.The replies in Bobs LG thread seemed to be a highjack,so I decided to see if the subject has legs of its own.While the decogging info on the site is valid,another option can be usefull or even an improvement.Instead of focusing on the rotor coming to rest at an ideal location as I originally suggested,could a segmented slipring be attached to the main shaft(similar to how a commutator works)to send DC power to the coils prompted by a relay activated by an annomometer?Any advances on this possibility?Cheers Rastus see Rastus graduate advise generously |
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Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
Rastus Sounds like a job for a picaxe with an input from the mill output at the rectifiers to turn off the pulsed DC. Its a bit over my head to build one But downwind, or Gizmo could breeze through it. Should work well with the boosters Bob has been using for low wind. ---Cheers, Roe Time has proven that I am blind to the Obvious, some of the above may be True? |
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| Rastus Guru Joined: 29/10/2010 Location: AustraliaPosts: 301 |
Hi Roe, Thanks for adding to the discussion,It's a rough idea at the moment and can be refined with help.Stopping the DC pulse or having control of duration would be practical,if it could be done using a picaxe function,how convenient.If a timer set at 5 seconds or less could be used that might be all thats needed.Raising problems to a proposal can lead to solutions as well.The discussion is open- Hope to hear from you again,cheers Rastus see Rastus graduate advise generously |
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| Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
Rastus Here's another Rough Idea, all Mechanical,Perhaps something similar could be useful? 
------Cheers, Roe Time has proven that I am blind to the Obvious, some of the above may be True? |
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| domwild Guru Joined: 16/12/2005 Location: AustraliaPosts: 873 |
Michael Lawley from ecoinnovation has been selling F&P mills with a floating hub to get around the cogging problem. He may no longer do so and is selling Chinese ones instead. I have had the cheek to ask him for the secret but he did not let on so I have designed my own idea. Have given up on the idea with my own PVC pipe props but will start up again with the float idea and fillm's props. The idea is to have a pipe with two bearings on the 25mm shaft. Those bearings are the standard 6205 bearings from the washer. The pipe carries the hub for the props. On the alt. shaft sits a spring-loaded hinge, which is hit from a bolt on the hub. If there is a separation of bolt from hinge, the prop starts turning and hits the hinge, which winds up the spring and may turn the shaft. In the best case, there is a close to 360 deg. separation between hinge and bolt and the prop can do a full turn before hitting the hinge to turn the shaft. Taxation as a means of achieving prosperity is like a man standing inside a bucket trying to lift himself up. Winston Churchill |
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| Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
domwild Here is another Possibility, Most of you are familiar with an over run clutch. a device that is built like a Roller bearing with an oval race. the rollers are forced to climb an inclined plane by the outside portion of the clutch which would be connected to the turbine blade, As the outer part rotates the rollers bind up as the clearance between the inner hub and the outside ring diminish. this effectively locks the turbine to the alternator. Sometimes the clutch can be found on Gearboxes. If custom built it may be possible to get 1/3 free revolution before lockup. 
------Cheers, Roe Time has proven that I am blind to the Obvious, some of the above may be True? |
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| Rastus Guru Joined: 29/10/2010 Location: AustraliaPosts: 301 |
Hi Roe and Domwild, Thanks for the posts,they are certainly food for thought.I've read somewhere that ecoinnovation move the rotor slightly so it doesn't cover as much of the stator to reduce cogging.The adjustment does slightly affect output as well.I'm unaware of a floating rotor and will investigate further.Another option could simply use a small ring gear on the main shaft and a small starter motor,that engages at a preset wind speed and a timer to dissengage.The parts could be sorced from of the shelf items.What do you think?Cheers Rastus see Rastus graduate advise generously |
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| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
A small anemometer type thing could be mounted on the mill and would drive a set of contactors or electronic switches that would pulse the coils. |
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| Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
Hi All I have been throwing out a few Ideas that would not require another set of wires up the Tower. A simple Gadget that can do the job would be cheaper and more reliable, The things I suggested would need refinement there is surely a widget that will do this, ----Cheers, Roe Time has proven that I am blind to the Obvious, some of the above may be True? |
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| Rastus Guru Joined: 29/10/2010 Location: AustraliaPosts: 301 |
Hi KiwiJohn and Roe, The more ideas the better.They may prompt imaginations and really become worthwhile!Roe,your mechanical idea started me thinking that if I used an alluminium ring to sheild the stator from magnetism the rotor would free wheel up to cuttin.The air vain could then remove the ring(shroud) and instead of the spring(which can fail) have a balance weight to allow it to return in light wind,to reset.The alluminium ring would need to be less than 1mm thick for F&P.No electrics at all.Its just a pipe dream at the moment but could develope into something with help.Whatever comes up,the winner will line up to the KISS(keep it simple st...d)principle.Cheers Rastus see Rastus graduate advise generously |
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| Air Bender Senior Member  Joined: 25/01/2011 Location: AustraliaPosts: 206 |
Hi Rastus What I am thinking about if I have self starting problems is to have a small electric motor with a rubber wheel on it and have it set up on a lever operated by a solinoid which would throw the motor and rubber wheel in against the magnet rotor on the F/P and back out again when disengaged. I dont think the motor would need to be very big as with a small rubber wheel up against the large magnet rotor would give it good gearing. Hopfully the new mill will self start OK but it may not too. All the best Dean. |
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fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
THAT'S IT IN A NUT SHELL,I would think the root of this discussion is " LOW WIND START UP and MAKING POWER IN THOSE CONDITIONS" Having a pulse start or any type of mechanical start aid just adds to complicated devices that eventually cause more hassel than they are worth , Multipul Pulse starting and the electric starts power consumption would need to be considered as a loss and it's use of power that then could/would take 1~2 hrs to replace the power from just one start, multipul starts on low wind days , is it worth it?. Kiwi John is probably one member here that has been around from when I was first started on the F&P Duals and would probably remember back to then( and its good to see you back John) , so for the others I will drag out some old threads and give my opinion and hopfully pass on some of what I have learned . My very First dual stator had a "Bump Start" which I modified a F&P agitator to turn the blades back 1 turn on a floating blade hub in wind under 3klm then when the puff came it allowed the blades to spin 1 turn and bump start the mill , SEE HERE, the blades were made from Indrustrial ABS pipe and at that time I thought they were the best thing next to sliced bread . It worked well but took so much stuffing around with and I was constantly adjusting it to get it working better. Star / Delta switching hasn't come up for a while and also gave that a go for a while and it's another fruitless path. The First big winner was getting rid of the ABS blades to the GOE 222 " A proper airfoil " . The ABS blades, which I spent Hours/Days++ trying to shape and get performing were USELESS in comparason . Shortly before the blades was the idea of twisting the poles to reduce the cogging which when done on a dual and correctly alinging the two stators almost eliminated the cogging to the point where the bump start did not even need to hit the bump to turn the dual , the blades would start to turn and get to the point where the mower start spring tension would start the alternator and it would just lag behind untill the alt loaded the blades enough to hit he drive pin. I remember standing there just watching it do its stuff and thinking " IT DOES'NT GET ANY BETTER " but it did ! I fitted the first set of GOE222 blades I was intending to also refit the "Bump Start" but from the first day it was obvious that it was not needed any more and is now another piece of old junk next to the Quad stator , dual neo f&P hubs , ABS blades laying around my shed . The "NEXT BIG" change was getting rid of the star/delta switching , mine was manual and required 12 wires down the pole for a dual , the cap/doubler eliminated that and allowed the maximium output from the Dual and did not overload the bottom end and allowed max output in med to high wind , basicly a MPPT when the correct uF is used . A lot of testing was done HEREand Gorgons origional VISUAL EFFECT OF CAPACITORS thread which comes back to the top has now over 1/4 million hits. So for the "KISS" rule - The best config I came up with was 1 x 100s (star) 1 x 80s (Delta) ,1600uF to 680uF 250V caps , 3m blade GOE222 for my low wind location. After building my first AXFX I compared the both HERE , no complicated electrical or mechanical add ons and where the F&P would match the AX up to around 16KLM which now with the cost of Neo's brings it back into play . Lastly a bit of a disclaimer and acknowedgement to those members past and present for their contributions and ideas to what I think was the Ultimate KISS F&P. " Glenn - for devloping the ALU/PVC design to the GOE222 profile" - "Jaybar" - I think for the pole twisting " Gordon - For developing the" CAP/DBLR " Lastly - Yes, I do sell the ALU GOE222 so it could be taken that I am Bias , well thats up to the person if they want to make their own or buy a proven wind generator blade. PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
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shawn Senior Member Joined: 30/03/2010 Location: New ZealandPosts: 210 |
Top marks Phill M I have to agree completly when the wind is going crazy you want simple, mine has twisted coils for low wind startup the only thing that varys is i sawed up some blades out of wood! oz style It starts up in low wind just turning slowly not making any power at all but ready for a gust. |
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| Jarbar Senior Member Joined: 03/02/2008 Location: AustraliaPosts: 224 |
Phill, thanks for the credit regarding pole twisting,but you forgot the original introduction of Wes from OEM to the forum by myself and the subsequent development work by Glenn and myself in designing the GEO222 blades.Originally produced in PVC you were supplied a set gratis to try out.Yes you have done some great work but don't take credit for that which you did not do. I still have PVC blades available for those who may be interested. Anthony. "Creativity is detirmined by the way you hold your tounge".My Father "Your generation will have to correct the problems made by mine".My Grandfather. |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5078 |
Yeah there's always been a bit of confusion on who developed what. Wes did post a request for help to design some blades for his windmill, some time ago, and it was largely ignored or forgoten about. Anthony sent me a message to remind me about the post, and provided the motivation to get things happening plus some good idea's towards its design. I spoke with Wes over the phone and once I discovered he had access to extrusion equipment, I drew up some hollow section profiles in CAD and sent them to him. I can take credit for the tube mounting system, but not the choice of profile, I dont know where that came from. My CAD drawings were a similar shape, but not what I would call a GEO222. Either way, the GEO222 is a good profile and has been used by wind turbine manufacturers for decades. Anthony became the Australian agent for the PVC blades. Wes later found he could get the blades made from extruded aluminium cheaper than PVC, so went down that path and Phill became the agent for the aluminium extrusions. There was some politics involved that I wont go into. Phill has since done a lot of development work with the extruded blades, in particular mounting systems, appropiate diameters, etc. He's the man with the know how, cause he's been there and tried it. So there have been a few cooks in the kitchen, all making important contributions. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
Everyone, The "who", "where", "what", "when", is important I agree, but it all happened on "the Back Shed" and has had an important place in upgradeing alot of mills and the developement of many more, such as my large vawt, who knows what will be developeed in the future. It has been a important contributing factor, and I'd like to say thanks to everyone again. with kind reguards...Mac46 I'm just a farmer |
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| Rastus Guru Joined: 29/10/2010 Location: AustraliaPosts: 301 |
 Hi to everyone,
Thanks for the posts.I feel I've stood on some toes without knowing.I apologies!!!That definately was not my intention.One other option for F&P is to use an early rotor with a recent stator which comes across as the simplest way to address cogging.I don't know who came up with that idea but all credit to you.For those who have developed the F&P to where it is may feel the subject is done and dusted and a bit affronted that I've asked for additional ideas.I stupidly thought,nothing ventured nothing gained?It was not intended to pip those at the post!If the post continues to be a can of worms it would be better to close it.I'll leave that to your discretion Glenn see Rastus graduate advise generously |
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| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
Hi fillm, I have never been very far away but I have not had a chance to play with F&Ps for some time. But we are now in a new house in a small town and I have a decent workshop, so who knows? Maybe there will be something soon! |
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| fillm Guru Joined: 10/02/2007 Location: AustraliaPosts: 730 |
Hi Rastus, I don't think you have steped on any toes , I added my post to the thread for where I got to with my journey with F&P's to help others and to try to say that the answers are not in complicated mechanical or electrical add ons . Anthony, I don't know where in my post, that I said I had credited myself with the origional design ideas to extrude the GOE222 Airfoil , you may have it mixed up with the ABS Pipe blades I origionaly cut and shaped from 300mm OD ABS pipe. John, good to here you are set up and have a good workshop, look forward to seeing what you start, where are you located in the land of the long white cloud. PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
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| Rastus Guru Joined: 29/10/2010 Location: AustraliaPosts: 301 |
Hi Phill M, Thanks for the additional comments,I must have been reading to much between the lines.I fully agree that any developements need to be uncomplicated otherwise potential faults will foil success.Running ideas past exsperience quite often weeds out problems and increases the potential of favorable ones.Whether this thread comes to anything remains to be seen!Cheers Rastus see Rastus graduate advise generously |
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