Questions on generator home build

Discussion in 'Windtura Generators' started by dlmcbm, Oct 19, 2010.

  1. dlmcbm

    dlmcbm WindyNation Engineer

    Hey all,
    I am thinking of playing around with building a generator. The big questions I have are wire size, how many wraps and strength of magnets? I know they all have something to do with volts and watts but what does what? I am thinking that this is not one of those cases were bigger is better. I am sure that I don't want 44 wraps of 6 gauge wire with the strongest magnets I can find or do I? I would love to hear the insites on this or even some pages that I could read up on it.

    Thanks all,
  2. windyguru

    windyguru WindyNation Expert

    If you want to do it yourself, check this page from

    Scroll down on the page to the section that has these links (this will clarify just about everything you need to know to get started):

    Metal Work Part 1: On this page we build the main chassis for the machine.

    Metal Work Part 2: On this page we fabricate the tail boom.

    Coil Winder: This page details construction of the coil winder.

    Stator mold: Details of the mold in which we cast the stator.

    Stator: Detail of winding the coils and casting the stator.

    Magnet Rotors: Building the magnet rotors.

    Alternator Assembly: Assembling the alternator

    Wind turbine blades: How to carve the blades

    Blade assembly: How to assemble the blades

    rectifier: How to build the 3 phase rectifier

    Towers: An older page with thoughts about towers and some ideas
  3. dlmcbm

    dlmcbm WindyNation Engineer

    hanks for tat Guru.I have seen that site. The guy goes into good detail of his prosses. From what I et from it is the number of windings has to do with voltage but what wuld you do to increase the amps? would it be bigger wire? Stronger magnets? or just more rpms? I guess I am more trying to understand how they work the way they do.
  4. bluejay

    bluejay WindyNation Engineer

    Thicker wire for sure and i am assuming more magnet power.For lower rpms..Thats why the different stators that you can buy for the delcos tell show you thicker wire needs more rpms to hit the voltage wanted but more amps will go out..
  5. windyguru

    windyguru WindyNation Expert

    Yes, thicker wire is needed for more amps. Thicker wire has less resistance which will allow it to more efficiently carry more amps. Not to mention, too many amps through a thin wire will overheat the wire/stator .... and the end result is a burnt out stator.

    As you said, the voltage of the generator depends on the number turns in the windings. So, if you keep the windings the same to maintain the needed voltage and make the wire thicker (to allow it to carry more amps), the copper stator obviously is going to occupy more space. Thus, the generator gets bigger in size.

    Additionally, it is the magnetic flux from the magnets that force the electrons to move through the copper stator. Obviously, this is what makes the electricity. So, now that you got bigger wire you need more magnets (or bigger magnets) to "push" more electrons through the copper wire.... so you can get more amps.

    But now you need longer blades because more torque is required to push more electrons. But longer blades spin slower than shorter blades! So now you got to increase the windings in the stator so you can make more volts at slower rpms to compensate for the slower/longer blades. Thus, the stator gets even bigger and the generator gets even bigger.

    The moral of the story is that wind turbines that make a lot of power have HUGE generators and HUGE blades! It is what it is.
  6. tunielooney

    tunielooney WindyNation Engineer

    Hi dlmcbm. What kind of renewable energy generator you want to build? If you have pics. of it, could you post it? I'll wait for your further respond.
  7. TomT

    TomT WindyNation Engineer

    Correct me if I am wrong but I have read that once you get above 6 ft to 7 ft the rpms really start dropping off. So to me if you are going to build one I would start with blades first and build a generator to use the blades most efficiently as possible for your wind conditions. It also depends on what voltage you want too. I am finding that 12v for low wind may not be a good idea. Might be better with 3 phase MPPT grid tie. Or 24v battery bank and switch using the 12v from both parts of the battery bank.
  8. dlmcbm

    dlmcbm WindyNation Engineer

    I have kinda dropped the idea of making one. The cost of wire and magnets is a lot to "test" something that may get thrown in the trash. I think I will leave it up to windnation to make good generators.

    Tom I agree with you on 12v in low wind. I bought a 12v delco generator because I wanted to charge 12v batteries. I did not fully understand how things worked when I bought it. If you want to charge 12v batteries I would still get one that is 24v and up. mine takes to many RPMs to even get to 12v that I am loosing a lot of usefull wind.
  9. Theo

    Theo WindyNation Engineer

    Hello all, anyone experimented with a treadmill dc motor?
  10. murray2paddles

    murray2paddles WindyNation Engineer

    Hi Theo,
    You probably just said the dirty word "treadmill". There have been so many posts disclaiming he use of car type alternators, treadmill motors etc. !
    Not that they don't work, it is the lack of efficiency.
  11. Minnesota

    Minnesota WindyNation Engineer

    Right ... the power out of a treadmill motor is very low, plus they are not designed for outdoor conditions and thus don't last.
  12. Theo

    Theo WindyNation Engineer

    Thanks for all the good feedback guys, I’ll make sure to keep away from these motors then. ;)
  13. dog

    dog WindyNation Engineer

    Why can't a DIY'er put a magnetic rotor , then the a stator , then a two sided magnetic rotor , then a stator , and then another magnetic rotor sandwiched ,? you might have to add two feet to the blades . Why Not ? :mrgreen: posting.php?mode=reply&f=27&t=432#

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