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Forum Index : Windmills : Vawt...going in a big way
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| anteror Senior Member  Joined: 06/10/2009 Location: FinlandPosts: 189 |
I myself have seen several sites and developements, that tried to "sell" these.. But in few words and with all my experience etc The surface area of blades, is the key and mast heigh, to produce energy. In a VAWT you need 2m X 5,6m (6,5 ft X 18,5 ft) to get the same power, that 3,8m (12,5 ft) dia HAVT gives ! (This is just 2kw windgenerator, that I have been using and testing for 3 years now.) Storm protection is easy with HAWT. With VAWT it is impossible, in dimensions that produce at least something. It is a different matter, if you want just some decoration object, to move in the wind ! This is the law of physics. Think about that. This vawt is something else..(mambo jambo..) Hugh Piggot has wrote a lot about this madnes; http://www.scoraigwind.com/ So has Paul Gipe; http://www.wind-works.org/index.html Test sites and etc you can find easily about all this. Just put some words in Google about this ! I am a retired private person, who has made a lot work and testing with windpower. This vawt is something very odd... in all this 
You can see pictures about my systems; http://kuvablogi.com/blog/34560/1/ If you really want some power.. from the wind, you need torque.. 
and with big blade surfice area; http://windmills.swnebr.net/windmills.html#new In the Wild West they allready could handle all this, with tail and its surfice area and angle etc to have power with oversized blades and from weak winds, in every place ! Antero Rantanen Finland |
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mac46 Guru  Joined: 07/02/2008 Location: United StatesPosts: 412 |
Hello anteror, I'm not selling anything...not promiseing anything...just shareing my build. If you'r right about you'r vawt's, then when I'm finished I"ll be in the same boat as you. So don't be so down trauden...if you can make a mistake and waste you'r time on them, then why can't I ? Regards, Mac46 I'm just a farmer |
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philb Regular Member  Joined: 05/07/2008 Location: United StatesPosts: 96 |
Hi Mac46, I just got time to read your thread. I've never built a VAWT before, but have enjoyed the read. Those green and red parts look so familiar. I was thinking if your brake doesn't work too well and you have a hydraulic pump and motor laying around, you might try that. Front end tractor loader pumps have worked well for me. Just an idea. 
Good luck! philb |
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Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
Mac46 Hi Mac, I've had a few thoughts about your planned Alternator for the big Vawt. The first, You mention Magnets of 2 inches square that you have your eye on, I believe I have an Idea that can improve on the speed of coil cutting, An Ideal magnet would be about 3/4 inch thick so that many more could be fitted around the Rotor. Three feet Diameter has a circumference of 113.04 inches.Divided by 3/4 = 150 dividing by equal spacing = 76. With the Two inch mags look at what happens At 2" spacing and 2" magnets it would be 28. The frequency of a slow rotor would be enhanced with a great number of Magnets. In this case, 76 mags at 30 rpm. it would be 38 CPS.or 38 hertz. This means that 38 magnets will pass a single coil in one second. With 2 inch mags the frequency would be 14 cps. this still would show something out but voltage in the coils would be low. The numbers here do not provide for coil winding entirely, this is meant for comparasion, adjustment may be needed. Next, Philb has a good idea on the hydraulic pump. I have thought about posting something like this before but backed off because of weight added to a very shaky pole with a hawt on top. This does not apply on the project you have going. I believe A pump would be a great governor on a big VAWT. It could be chain geared to low speed so it will not be a load of any significance. at normal speed piped into a spring loaded cylinder with a fluid relief grove, the higher the speed the more fluid is pumped, the cylinder piston moves against the spring and uncovers more of the grove,EDIT, or holes. EE, to maintain a near constant speed. Just chit chat, hope to see some progress. --------Cheers, Roe Time has proven that I am blind to the Obvious, some of the above may be True? |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
Hello Philb, Greenbelt, everyone, "Yes", I do have extra hydralic pumps and motors just laying around...and Thats an extra=great idea!!! I believe this could be made to work, and work well. Thank you for this suggestion philb. Greenbelt, I have just ordered in a box of ceramic magnets, 1x2x2", 60 ct.@ $1.68 each I believe, they should be here in the morning. I am very interested with you'r plodding vawt posts and I thank you for you'r input with this project. I have'nt had the ability to test this animal much. I need to beef up the overhead beams and make a few other modifications before real tests can be made, but it indicates that it will run at over 100 rpm in a 20 mph wind under load...the load being the break "applied at max." The break did over power the mill and finely bring it to a stop...but it burnt the break lineings up doing it. Thank you both for the suggestions. Mac46 I'm just a farmer |
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Rastus Guru Joined: 29/10/2010 Location: AustraliaPosts: 301 |
Hi Mac46, Thankyou for the helpfull hints.I feel an obligation to try the circular saw idea having proposed it in one of my earlier threads and although F&P's are not as current now,there was some interest in being able to exstend spline length with everyday type tools.Of course there where doubters to,so nothing ventured nothing gained.Cheers Rastus see Rastus graduate advise generously |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
Hello Rastus, I'm noy sure if a circular saw is the safest way to be doing this...you could be hurt, you can't see very well and can't control you'r cut. If you have one, a 4 1/2" right angle grinder would be a good choice, followed up with finishing by way of a hand file. These small grinders are fairly inexpensive and they also have different thickness wheels available, I think as thin as 0.080" ...just be sure to use safety glasses and be mindful as to where the sparks are going...don't want to start a fire or do damage to any thing. Regards, Mac46 I'm just a farmer |
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| Rastus Guru Joined: 29/10/2010 Location: AustraliaPosts: 301 |
Hi Mac46, My brother has just sms'd me with the news he's made the grinding wheel hub for the saw. So I'm getting closer to go.I might get it by post mid next week.The safety warnings are greatly apreciated.I'll resurrect the F&P spline thread with the results,with pics.It will be my first attemp to work that out.Cheers Rastus see Rastus graduate advise generously |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
Hello everyone, I finely got back to this project, I finished wireing up the 240 volt service and juced it up...everything checks out ok. Now I can run the welder and power equipment without haveing to drag out a 100 foot of heavy power cable. This will help make things alittle easer. Mac46 I'm just a farmer |
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| Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
Greetings Mac46 I agree, when you get urge to work on the Mill a few minutes you do not have to face the job of dragging out the 100 ft. 8 gage cord and putting it back. many times this would be a deterrent to even start, especially when tired. Now you can drop things where they are and continue later. Did your Magnets show up yet? and are you satisfied. what is the Gauss value, No that's not what I mean. I'm interested in the total field strength in pounds of lift, not the density of the field? Time has proven that I am blind to the Obvious, some of the above may be True? |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
Hello Greenbelt, Yes the power cord is a hassel to get out and put back away each time, but I do put it back and lock things up just the same...can't be to careful now a days. Yes, I believe its 4 gauge copper...a real temptation to a passer by, not that I have any passer buys out here. The magnets arrived the other day, I don't have the specks on them handy, but from memory they were a grade #5, 1"x2"x2"...times 60 pieces. They are a bugger to separate from one another for being ceramic. I have'nt started playing with them yet, still to much other stuff going on around here. I'll take the magnets to the shop and put one on a piece of heavy steel to try to get a estimate of pull strength and get back with the info. Regards, Mac46 I'm just a farmer |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
Hello Greenbelt. Ok, according to the scale ..."one magnet" will lift approx. 10 pounds and thats laying flat on a sheet of 1/4" steel plate with more lift to spare. the shipping info is as follows...part#cb1862n cers5 1.0 x2.0 x2.0 60,000 +/-.005; .04; .06 M 60,000 CA .04.A.01 I'm not sure if this is exactly what you'r asking or not. the weight lifted was just because I did'nt have additional weight handy...but I feel 10 pounds would be pretty close...plus alittle more, say a 1/4 pound or so. Regards, Mac46 I'm just a farmer |
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| philb Regular Member Joined: 05/07/2008 Location: United StatesPosts: 96 |
Mac46, I'm glad you got your magnets. It looks like ceramics are the way to go. I still have plenty of neos but I'm thinking about selling my neos and going with the ceramics. The neos will pay for a new complete ceramic turbine, maybe two. The corrosion factors on ceramics are much less. There was a ceramic magnet attached to my metal tin barn for years. It never did corrode. Bergey's 10 Kw turbine uses ceramics...a whole bunch of them. Some of the older units are now loosing their magnetism, but have lasted for about 20 years before that happened. I have one of the first ones made. It is resting in my pasture now, but I hope to rebuild it in a year or two. I'm glad to see other people here and on the Otherpower site resurrecting the older way of making turbines.  philb |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
Hello philb, Thank you for the kind words, I have'nt built a single generator/alternator yet...so I've alot to learn. Cost is the major factor for me to choose ceramic magnets...that, and that they seem to last (like you say), for years. It will be alittle while before I get going on this generator...probably a few mounths. I'd really like to get some testing done on my mill first so I know about where the thing wants to run speed wise, and about how much power it has at that speed range. This will be a good thing to know before I build the generator. Regards, Mac46 I'm just a farmer |
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| philb Regular Member Joined: 05/07/2008 Location: United StatesPosts: 96 |
Hi, Mac46, Maybe you could rig up a prony brake to get a better idea. I just googled that and found a bunch of information, including pictures. That will give you a good idea of what you need. Building wind devices are addictive so be careful!  philb |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
Hello philb, Its to late, I'm hooked on these things. I've googled proney break myself awhile back, very interesting. I also rechecked the pull strength on my magnets...just to be certain that I had the scale set correctly, and I also checked several to see if they were consistant, which they are. plus or minus 1/10th. of a pound, I checked 10 out of the 60 magets, the average came to 10.4 pounds. (bugger to get apart from each other,)I can only just imagine what neos are like. Regards, Mac46 I'm just a farmer |
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| Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
Mac46 Hi Mac I've been busy. yes, the Tag info is good and the manual test is better. For the thing you plan to build these should work, I'm doing some research on the Gauss Maxwell, Orstead, Weber,Tesla, Henry and others to find a formula for inductance that i can make sense of. What I have discovered is that many of the values of units in magnetism are duplicated with someone's proper name attached, mostly to make it seem more difficult than it is. The Tesla seems to be the modern value of magnetic field strength. from the Tag info on yours they are (.6 Tesla), (6000 Gauss). 1 Tesla = 10,000 Gauss.100,000 Maxwells.>>> If you get a chance try the Magnet scale test with a piece of heavy cardboard or other substitute for a clearance gap between the steel plate an get an idea of the working force you have to work with. I ran on to some info on the net that suggests 1/2 of the Magnetic field is lost across the air gap so this is important to know what value exists to base the coil design. More Later -------------Cheers, Roe Time has proven that I am blind to the Obvious, some of the above may be True? |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
Hello Greenbelt, I have been doing some reading on this as well...very difficult to make any good sense off, finding it hard to relate the info to, or translate it to something I understand as a comparision. Also, I've been wondering if a thick plastic center placed inside of each coil would help to direct the magnetic field through the coil windings, and also elongated coils or different shapes other than round to possibly focuss the magnetic fields. I've got a few ideas to test out. I've got to tell you...I greatly appreciate you'r interest and input, as well as input from other members and builders. I'll try to set some time aside to check the pull strength of the magnets with heavy cardboad...both as a single magnet, and also as a maching set. Regards, Mac46 I'm just a farmer |
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| mac46 Guru Joined: 07/02/2008 Location: United StatesPosts: 412 |
Hello Greenbelt and everyone, Alright, With one magnet, layed flat as before, and with one layer of 1/8th. inch cardboard...the pull strength dropped from 10.4 ibs. to approx. 8.3 lbs. With the same set up as above, only with 2 layers of the same cardboard, (now 1/4") thick, the pull strength dropped below 5 pounds. I'm not sure how far it dropped because I did'nt have time to continue. I did'nt test any double magnets. So the strength does drop off dramaticly with increased air gap. I need to do more testing to gather some accurate figgures...Info such as what I just listed is useless. I'm buseyer than a one legged cat in a sand pit. Regards, Mac46 I'm just a farmer |
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| Greenbelt Guru Joined: 11/01/2009 Location: United StatesPosts: 566 |
Mac46 Hi This will not replace a test coil but will give an idea of what it's all about-------cheers, Roe Basic Inductance Time has proven that I am blind to the Obvious, some of the above may be True? |
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