Author Topic: Active Pitchcontrol  (Read 331754 times)

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mbouwer

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Re: Active Pitchcontrol
« Reply #627 on: April 16, 2017, 05:40:20 AM »
It would be nice to meet someone on this forum who also is interested in making the generator.
 
« Last Edit: April 16, 2017, 05:45:47 AM by mbouwer »

mbouwer

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Re: Active Pitchcontrol
« Reply #628 on: April 17, 2017, 08:04:52 AM »
On the circumference of this generator rotor-ring I can glue 64 neodymium magnets ( 20 x10 x 2 )
What then is the best arrangement for the coils?
« Last Edit: April 17, 2017, 11:42:20 AM by mbouwer »

mbouwer

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Re: Active Pitchcontrol
« Reply #629 on: April 18, 2017, 01:21:09 PM »
In this coil configuration. Do I also take the ratio 4 magnets on 3 coils?

hiker

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Re: Active Pitchcontrol
« Reply #630 on: April 18, 2017, 02:03:36 PM »
WILD in ALASKA

joestue

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Re: Active Pitchcontrol
« Reply #631 on: April 18, 2017, 03:18:59 PM »
In this coil configuration. Do I also take the ratio 4 magnets on 3 coils?

The blue coils would be positioned over the north pole of the magnets, with the south poles in between them.

As shown, each of the coils would be wound in the same direction. O O O O

If you wind the coils like this OOOO then every other coil is reversed (you will also have twice as many of them), and you also have two coils in each slot. usually they are wound this way because the end turns are slightly shorter, but it may be harder to get the wires into the slot.

I suggest you try a 66 slot machine. the wiring diagram can be found here:
https://www.emetor.com/edit/windings/

you may be able to wind the coils over the top of a laminated metal backing plate without using any slots cut in the metal. the frequency you get out of this thing is going to be very high. you may need to use fine wire due to eddy currents in the wire. (you will have to anyway because the coils will hardly be 1cm in width)

In my opinion a more reasonable option is to make a 32 pole machine, which might get you more torque due to less leakage flux. the magnet poles would be square in cross section which is more ideal, you just arrange the 64 magnets like this: nnssnnssnnss.

a 32 pole machine can't use a 33 slot stator unless its a two layer winding which is more complicated to make, but a 30 tooth stator is a good fit and the least common multiple is still rather high at 480, much better than a 96 slot stator which would have an lcm of.. 96. but not nearly as good as the lcm of 2112 for the 64 pole, 66 slot machine. higher LCM= less cogging torque.

« Last Edit: April 18, 2017, 03:38:47 PM by joestue »
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mbouwer

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Re: Active Pitchcontrol
« Reply #632 on: April 19, 2017, 03:56:38 AM »
Can we say that working further with this ring and these magnets is not going to bring a nice generator?
The metal work is no problem for me.
How to make a new start?

hiker

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Re: Active Pitchcontrol
« Reply #633 on: April 19, 2017, 12:39:34 PM »
whats the problem ? 
WILD in ALASKA

joestue

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Re: Active Pitchcontrol
« Reply #634 on: April 19, 2017, 03:36:24 PM »
Its just a challenge of how to build the stator.

If you can take steel pallet banding strap and anneal it in a furnace, you maybe able to wind it edge wise around a cylinder, then use it as a backing plate to glue the coils to. 
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CraigM

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Re: Active Pitchcontrol
« Reply #635 on: April 19, 2017, 04:32:00 PM »
Remember seeing this posted by oztules

"Yes, I was going to suggest the iron wire technique. I did a story on the Seeley conversion here."  http://www.otherpower.com/images/scimages/5171/seely.html, and one of the photo's clearly shows the iron wire backing like this:
  .... may help?

CM - Use a soft, very low carbon wire.
Brain engaged in Absorption Charge Mode... please wait, this may take awhile.

CraigM

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Re: Active Pitchcontrol
« Reply #636 on: April 19, 2017, 05:02:54 PM »
Another option if you can find it is to use the "I" section of an E transformer, tape them end to end and wind a toroid core. Your flux lines will enter the flat side of the laminate instead of the edge... not sure how much loss this will incur.

I was able to find packages of silicon steel "I" sections at the local scrapyard. Have a bunch of this stuff and not sure what to do with it.
Brain engaged in Absorption Charge Mode... please wait, this may take awhile.

joestue

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Re: Active Pitchcontrol
« Reply #637 on: April 19, 2017, 05:41:12 PM »
how thin are those laminations?
if they are .010" or less i can use them to make inductors for sine wave filters for vfds, but i'm not sure i'll use them either..

He could wind a toroidal core with those strips of metal, but... he has a radial machine, not an axial one, the laminations need to be oriented 90 degrees to the induced voltage.
My wife says I'm not just a different colored rubik's cube, i am a rubik's knot in a cage.

mbouwer

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Re: Active Pitchcontrol
« Reply #638 on: April 19, 2017, 05:51:36 PM »
The metal work is no problem for me.
But I think that does not mean that I am capable to make a generator on my own.
Can we start to talk about a design that others also want to make. Perhaps cooperation is possible.
« Last Edit: April 19, 2017, 05:59:29 PM by mbouwer »

joestue

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Re: Active Pitchcontrol
« Reply #639 on: April 19, 2017, 05:57:03 PM »
if you re-orient the magnets so you have two of them facing each other, an inside and outside cylinder, you can make a radial air core design.

another alternative is use the outside of a large motor core as a slotless core.
there is a photo here of the method.
http://www.fieldlines.com/index.php?topic=143518.0
My wife says I'm not just a different colored rubik's cube, i am a rubik's knot in a cage.

mbouwer

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Re: Active Pitchcontrol
« Reply #640 on: April 20, 2017, 05:45:04 AM »
It's a pleasure to read all your comments.
Only with your support I'm going to manage to make a radial generator

electrondady1

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Re: Active Pitchcontrol
« Reply #641 on: April 20, 2017, 08:26:26 AM »
you seem to do very nice metal fabrication.
 i don't understand if you have 64 mags with mounting holes and another 64 mags without mounting holes .
why would you not build a dual rotor radial alternator with an air core stator and avoid all the coggeing?

« Last Edit: April 20, 2017, 08:39:40 AM by electrondady1 »

mbouwer

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Re: Active Pitchcontrol
« Reply #642 on: April 20, 2017, 03:13:10 PM »
That's what I will do. Air core stator with 1 layer of coils.
36 magnets and 27 coils.

mbouwer

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Re: Active Pitchcontrol
« Reply #643 on: April 21, 2017, 05:47:52 AM »
The coil winder for the coils with inside measure 20 x 10 mm

« Last Edit: April 21, 2017, 05:54:17 AM by mbouwer »

mbouwer

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Re: Active Pitchcontrol
« Reply #644 on: April 22, 2017, 05:11:29 AM »
Coils 100 and 50 windings / wire 0,5 mm
Mounted with the rotor at 100 rounds per minute the biggest coil shows 0,05 volt.

Bigger magnets and coils, thinner wire.....?

« Last Edit: April 22, 2017, 05:26:10 AM by mbouwer »

Adriaan Kragten

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Re: Active Pitchcontrol
« Reply #645 on: April 22, 2017, 08:50:05 AM »
If you use a stator without steel lamination in it, you should use rather thick magnets other wise the magnetic resistance of the air loop wil be rather high with respect to the magnetic resistance of the magnet itself. This will result in a rather low magnet flux flowing through the coils. In my recent report KD 631, I describe an axial flux PM-generator with no iron in the coils and even with 15 mm thick magnets there is a large reduction of the magnetic flux in the coils (see calculations in chapter 3). The same theory can also be used for a radial flux generator.

electrondady1

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Re: Active Pitchcontrol
« Reply #646 on: April 22, 2017, 09:05:16 AM »
dual rotor required
add another rotor on the outside of your present one  with another 32 magnets.
cast a 2 phase stator with overlapping coils
 a total of 64 coils and 64 magnets


electrondady1

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Re: Active Pitchcontrol
« Reply #647 on: April 22, 2017, 10:07:56 AM »
       ......
       :....==coils   
       :
 mag:rotor
       :
       :.....
       :.....==coils
« Last Edit: April 22, 2017, 10:26:43 AM by electrondady1 »

mbouwer

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Re: Active Pitchcontrol
« Reply #648 on: April 22, 2017, 02:56:29 PM »
Something like this?
« Last Edit: April 22, 2017, 03:01:13 PM by mbouwer »

joestue

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Re: Active Pitchcontrol
« Reply #649 on: April 22, 2017, 10:24:51 PM »
yes, just like that.
My wife says I'm not just a different colored rubik's cube, i am a rubik's knot in a cage.

mbouwer

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Re: Active Pitchcontrol
« Reply #650 on: April 23, 2017, 07:26:33 AM »
But then I would prefer to make an axial dual rotor type first.

electrondady1

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Re: Active Pitchcontrol
« Reply #651 on: April 23, 2017, 09:01:32 AM »
i always build dual rotor axial flux machines .

with out a second rotor to draw out the magnetic flux you will need iron behind your coils. otherwise the magnetic flux is traveling sideways from one magnet to the next and not through the coils at 90 degrees.
from discussions here on other power i have come away with the understanding that the least cogging type metal backing can be created using mild steel wire wound in several layers behind the coils.
you have displayed good metal working skill so you could create a support bracket that could contain the coils and the wire backing . good luck
 

 
« Last Edit: April 23, 2017, 09:08:51 AM by electrondady1 »

mbouwer

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Re: Active Pitchcontrol
« Reply #652 on: April 24, 2017, 07:04:35 AM »
Your idea about using mild steel in several layers apeals to me.
I made these support rings for the magnets.(dual rotor) Perhaps next time I could use thinner layers.
« Last Edit: April 24, 2017, 07:14:08 AM by mbouwer »

electrondady1

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Re: Active Pitchcontrol
« Reply #653 on: April 24, 2017, 08:38:57 AM »
in the photo posted on reply no.365 you will see wire backing behind copper coils

mbouwer

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Re: Active Pitchcontrol
« Reply #654 on: April 24, 2017, 12:06:10 PM »
Reply 635 of Craig M.? But does'nt this steel wire become magnetic then?
How about a poured stator from one of the shops Mary B showed in Reply 554

CraigM

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Re: Active Pitchcontrol
« Reply #655 on: April 24, 2017, 01:14:26 PM »
Mbouwer,

I'm amazed how quickly you can fabricate something like your latest support rings. Maintaining concentricity from inner ring to outer ring doesn't look easy.

I believe a point you may be missing is the need for a closed loop magnetic circuit. In your original radial design you have a ring with magnets on the ring placed N-S-N-S. The metal ring allows the magnetic field to pass through the metal from N pole to S pole. This is one half of the magnetic circuit. The second half (to close the loop) is on the top of the magnet. With your design there isn't a closed loop. The best it can do is for the magnetic field to jump sideways to the adjacent magnet. If you place a coil over the magnet you will get very little flux passing through the coil.

To correct this you need to have a magnetic conductor directly above the magnets. You want to sandwich your coil between the magnet and the conductor with as little air gap as possible.

You can't simple attached your coils to a solid metal plate or ring. this would complete the magnetic circuit however the problem is as you sweep the magnetic field through a thick metal plate you'll induce eddy currents which result in heat. Others here can elaborate on eddy currents.

Electric motors use laminated steel cores. The laminations are very thin and the steel used is specialized to reduce eddy currents.

If you have access to silicon electrical steel you might be able to find someone to punch out a laminated core that fits the rotor you already made. You may be able to find a steel core from a motor but would then need to remake you rotor to match. Other option is to build your stator to match the rotor dimension and then wrap low carbon wire around the back side.

Think of the magnetic field needing to complete a looped circuit with the coils placed in the middle of the circuit.

Steel core (wire or lamination)
     |  Coil  |
Magnet N , Magnet S

Magnetic field loops from N to S or S to N. Flux jumps the air gap with coil and then travels through the steel core and returns to the opposite magnet.

Thanks CM
Brain engaged in Absorption Charge Mode... please wait, this may take awhile.

mbouwer

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Re: Active Pitchcontrol
« Reply #656 on: April 24, 2017, 05:08:41 PM »
Building small windmills is a worldwide activity and I enjoy making parts. Also for windmillfriends.
Until now the generator is a bit of a struggle for me. Mainly because I would like max. 100 rounds per minute and a high voltage.

Now, making a dual axial generator whith air core, what to say about the closed loop magnetic circuit?
« Last Edit: April 24, 2017, 05:14:46 PM by mbouwer »

electrondady1

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Re: Active Pitchcontrol
« Reply #657 on: April 24, 2017, 11:29:33 PM »

i would say yes .
 a dual rotor axial flux is very forgiving mechanism
with adjusting screws on one of the rotors you can make up for short comings in your construction abilities.
 with a radial layout (no adjustment)  clearances are set and must be perfect.

i don't recall anyone building a radial alternator on this site over the last 12 years


 
 

mbouwer

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Re: Active Pitchcontrol
« Reply #658 on: April 25, 2017, 05:52:48 AM »
Idea for making the shaft. I took 2 mm sandwich suspension plates for stiffeness.

joestue

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Re: Active Pitchcontrol
« Reply #659 on: April 26, 2017, 12:24:34 AM »
you only need laminated plates when the magnetic field is moving relative to the plate.
My wife says I'm not just a different colored rubik's cube, i am a rubik's knot in a cage.