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Forum Index : Windmills : DIY Generator
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MacGyver Guru  Joined: 12/05/2009 Location: United StatesPosts: 1329 |
Has anyone built their own generator or alternator from scratch? I did it 35 years ago and am about to embark on another try. This go-round, I intend to spin a wheel containing permanent magnets past a "C" coil pick-up. It will generate single-phase alternating current, which I will flatten out with a dual-bridge rectifier. The last time I did this, I remember having frequency problems. Anyone else been down this road? Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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| Janne Senior Member  Joined: 20/06/2008 Location: FinlandPosts: 121 |
Hi, doing a search for "axial flux generator" might be worthwhile, if you're making an alternator from scratch.. The "C" coil pickups sound like a manufacturing nightmare. If at first you don't succeed, try again. My projects |
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oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686 |
Thousands of people are building their own from scratch. It makes sense as the commercial ones are really not suitable for decent power at low rpm... so you have to make your own if your after serious KWH in mild winds and low rpms. Any one/any thing can make some power in strong winds. It also depends on what magnets you wish to use. If Neo's are available, then the axial flux three phase alternator will be nearly impossible to beat for simplicity, and efficiency and ease of construction. It does not use the available magnets efficiently (smaller magnets with steel in the coils makes more efficient use), but makes the best alternator for direct drive wind power that has been devised yet. There are few alternators direct drive that can come anywhere near the low rpm power that these things put out. The added advantage is that they are usually three phase, (less vibration, and better efficiencies) and have only 1 rotating part. Motor conversions make better use of magnets, but are far less effective than the axials, and suffer all the problems that armature reactance in steel cored machines bestows in the project... including runaway, and higher running speed. It is unusual to run these in stall limited operation.... which makes them more exciting than an axial running stall limited. ( very sedate and unexciting.... just how I like it). Doing single phase and using C coils pickups will work, but will be a poor cousin of the dual axial .... power generation wise. It would be a nice curiosity though. A shabby version of mine is here. http://www.fieldlines.com/story/2008/8/18/83321/8140 ...........oztules Edit: I can't seem to get the link to work, so you will have to cut and paste it. Village idiot...or... just another hack out of his depth |
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niall1 Senior Member Joined: 20/11/2008 Location: IrelandPosts: 331 |
hi Mcgyver over here (europe kind of ) Hugh piggotts designs seem to be the diy approach ...his older brake drum type is interesting too...good luck with the build........35 years ,. naughty boy ps...oz whats the gap between rotor and stator on that beast ?....i like the extra mounting points on the stator... if one loosens ( mine did on one machine ....  .. )........it dosent necessarly mean rubbing problems ...  niall |
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| oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686 |
Niall, It is about 20mm gap 16mm stator, 2mm per side gap. The excessive number of mounting points allows for very robust torque abilities. It can stop in a gale with no sound at all in the braking, or shudder in the stator. All the arms are 1/4" thick steel. ......oztules Village idiot...or... just another hack out of his depth |
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| MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329 |
Janne: The C-coil pick-up is a cake walk. I'll post pictures on a Web site in due time. I'll also put up a set of plans and a tutorial for the rest of this crew. The reason I'm doing single-phase AC is because I make the electricity in my shop -- down on the ground. That way I can control it better. All the windmill does is pump air to a receiver and I reclaim the power with a little air engine I design and build. That'll be on the Web page too. I like to keep as little as possible up there whizzing around atop the tower! All my windmills do is pump a little gulp of air with each spin of the turbine. One of my sons is a PhD Aeronautica Engineer and has told me for years "That won't work, dad." Too late. Not only does it work; it's fun to watch. I'll try to post a video of the air engine pulling the generator when the time comes. Nothing difficult is ever easy! Perhaps better stated in the words of Morgan Freeman, "Where there is no struggle, there is no progress!" Copeville, Texas |
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marcwolf Senior Member Joined: 08/06/2009 Location: AustraliaPosts: 119 |
I have a very interesting book circa late 1890's re building your own generator. It has such gems in it like talking to your local friendly blacksmith about making the armature and frame. And including the observation that if you made 2 of them then you can use the second to drive your wife's pedal powered sewing machine. One of those books that are handy should civilisation goes up in smoke (Like my sliderule and book of Log's) Dave Coding Coding Coding.. Keep those keyboards coding.. RAW CODE!!!!! |
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