Model Engine Maker

Supporting => Engine Ancillaries => Topic started by: old-and-broken on September 15, 2013, 08:27:43 PM

Title: 16 pole 4 phase model generator.
Post by: old-and-broken on September 15, 2013, 08:27:43 PM
On your marks

Get set

Go!

The project started before I knew it had begun.  My grandson wanted something to do one weekend.  He's 6.  I pointed out an old box fan and asked him if he knew how it worked.  He shook his head, and said no.  I handed him a screwdriver and a set of wire cutters.  Then I found a chair and watched the wonderful acts of childhood discovery begin.  Here is what he started with

(http://picoolio.net/images/2013/09/15/PjBoxfan.jpg)

When the dust settled and the hand tools cooled off, this is what I had.

(http://picoolio.net/images/2013/09/15/PjDisassembled.jpg)

The sharp eyed reader will notice that there are two motors there, less one cover and one rotor.  The two stators will be mounted together as one and the rotor will be turned down a fraction to allow room for the magnets.  Speaking of magnets.  I needed some for this project.  So...

(http://picoolio.net/images/2013/09/15/Pjmagnets.jpg)

I tried winding some wire around one of the stator 'horns' and quickly determined hand winding the coils was not going to happen in my lifetime.  I remembered that I had machines which remove metal, and if I used those to remove the wings on the ends of the stator poles, I could wind the coils on an insulating form and then just 'slip' them on the poles.  I did some digging and found where I had stashed some 1/64 thick ABS plastic sheeting.

(http://picoolio.net/images/2013/08/24/Pjwinding_insulation.jpg)

 A little measuring and a few bending experiments later I came up with the method of making a rectangular shape on which to wind the coils, and then I should be able to slip these, pre-wound with wire, on the stator poles.

(http://picoolio.net/images/2013/08/24/Pjinsulation_closeup.jpg)


That brings me to today, and my little job for the X2 mill.  Some scrap aluminum to hold the stator up and some 5/16 bolts to hold it down.

(http://picoolio.net/images/2013/09/15/Setup_for_first_cut.jpg)

An MT3 collet holding a 3/16 four flute endmill, and expertly placed in position with the aid of an eyeball that was last calibrated in 1962.   :Lol:

(http://picoolio.net/images/2013/09/15/Setup_for_first_cut_closeup.jpg)

Now, unfortunately, I have to power down the computer, so I can power up the little mill.  We don't have a proper 'working' outlet in the shop room, which is also where the computer resides.  I'm scared to have the mill running on the same little power strip as the computer while both are on.  I  can't afford a repair on the computer if something should happen.

More to come,
Mark



Title: Re: 16 pole 4 phase model generator.
Post by: ths on September 16, 2013, 11:51:06 AM
Well, I'm interested...

Hugh.
Title: Re: 16 pole 4 phase model generator.
Post by: steamer on September 16, 2013, 12:12:58 PM
Yes!  Very Interesting!

Dave
Title: Re: 16 pole 4 phase model generator.
Post by: old-and-broken on September 16, 2013, 09:42:13 PM
Okay.  I'm off to a slow start but I foresee this little machining operation picking up speed.  I have 64 of those little 'bumps' to trim off.  Here I have 5 of them removed and a 6th one mostly off, just needing a final pass to bring it into alignment with the pole.

So, 58 more to go.   :cartwheel:

(http://picoolio.net/images/2013/09/16/First_cuts_on_stator.jpg)

This picture is from yesterdays evenings play session.  I'm just in from a long 12 hour day making the donuts and I'm gonna take a little nappy-poo, but I'm eager to remove about 8 to 10 more of the little tits later this evening.  :P

More to come,
Mark
Title: Re: 16 pole 4 phase model generator.
Post by: sshire on September 17, 2013, 01:39:29 AM
Really watching this, Mark. My electrical theory is somewhere south of zero. Very curious how this is going to play out. Keep going.
Title: Re: 16 pole 4 phase model generator.
Post by: old-and-broken on September 24, 2013, 04:52:27 AM
About 12 completed cuts on the stator and my CHEAP chinese endmill stopped cutting and started rolling up thin sheets of swarf.  At first I thought I might have been feeding to fast.  I finished the cut and started another.  It was a complete wash.  I stopped before the rolled up metal shavings, which never detached, deformed the work piece too much.  The tool is now as dull as mono-toned psycho-analyst.

Got a good paycheck Friday, and after groceries and a much needed haircut, decided I had enough to spare for a new, HERTEL double ended End mill.  Four flute, TiCN coating.  A real coating, not that yellow magic marker stuff on the cheap chinese endmill.   :Mad:    Harbor Freight has good deals, but end mills are apparently not one of them.  Looking forward to diving in again in just a couple more days.

Don't worry, the project is still a go, but I'm only slightly faster than continental drift.   :lolb:   

Sorry to have posted without any progress to report.

Mark
Title: Re: 16 pole 4 phase model generator.
Post by: swilliams on September 24, 2013, 10:08:07 AM
I'm just in from a long 12 hour day making the donuts and I'm gonna take a little nappy-poo ...

Are you realise how that reads for us non-Americans??   :lolb:


http://en.wikipedia.org/wiki/Diaper (http://en.wikipedia.org/wiki/Diaper)

but seriously - this is a cool thread, I'm following

Cheers
Steve
Title: Re: 16 pole 4 phase model generator.
Post by: b.lindsey on September 24, 2013, 11:45:42 AM
Its not a race Mark, so take all the time you need or want... I'm following along too but admittedly, all this electric and electronic stuff is more like black magic to me :)

Bill
Title: Re: 16 pole 4 phase model generator.
Post by: Tennessee Whiskey on September 24, 2013, 10:31:36 PM
As it was to Edison, but, I'm watching also

 Whiskey
Title: Re: 16 pole 4 phase model generator.
Post by: steamer on September 25, 2013, 10:39:30 AM
Your doing fine....and it's not a race...keep going.....I'll keep watching! :ThumbsUp:

Dave
Title: Re: 16 pole 4 phase model generator.
Post by: Ian S C on September 25, 2013, 01:52:42 PM
Good work Mark.  There is another way of making armatures, you may be familiar with the claw type used in automotive alternators,  I have made two of these type of armatures for little alternators, instead of a wound electo - magnet, I used donut shaped magnets, they either came from the Magnetron in a micro wave oven, or a loud speaker, I'm not sure but I used three or four magnets.    Ian S C
Title: Re: 16 pole 4 phase model generator.
Post by: jwcnc1911 on September 25, 2013, 02:03:52 PM
Ian,

I see all of your posts and wonder if there's anything you don't know.  I'm convinced you should write a book!

All this electronics stuff is just black magic to me.
Title: Re: 16 pole 4 phase model generator.
Post by: old-and-broken on September 29, 2013, 11:07:47 PM
Half-time folks.  One stator, cuts completed, is ready to receive windings.  Still one to go, but this one will go faster now that I have a better end-mill.  The steel is super soft and cuts like butter. 

(http://picoolio.net/images/2013/09/29/stator_complete.jpg)

The damaged area is small and although I made a big fuss about it, I doubt it will cause any problems.  I can put that side in the middle and when the two pieces are pressed together with bolts, the offending leaves will lay flat.

Slow and steady.  I won't win any races, but like you guys have said.  This isn't a race.  It's an adventure; wait, that was something else.  :insane:

Next update should be much quicker than this one.

(http://picoolio.net/images/2013/09/29/damaged_area.jpg)


Title: Re: 16 pole 4 phase model generator.
Post by: old-and-broken on January 05, 2014, 04:16:00 PM
I still intend to finish this project, but I was side railed by a rather severe medical problem.   Almost good as before now.  Medication working and strength returning, I foresee getting going on the finishing cuts on the stator sometime next week.  Whether the whole thing works as I desire is another thing.  I just want to finish this thing I've started.

Also the Title is incorrect now that I have had sufficient time to think about things.  Since I intend to use just 12 magnets, it should factually be titled a 12 pole 4 phase model generator, because the number of stator poles is not a proper way to identify multi-polar generators.  Still the math was correctly applied and it will generate 60Hz AC at a mere 600 RPM.  So, for those who still give a Hoot.  Owl be getting back to model making in a few days.


Mark
Title: Re: 16 pole 4 phase model generator.
Post by: Don1966 on January 05, 2014, 04:43:39 PM
Mark I have been following along with great interest. I am curious to see how you get four phases out of  12 pole. It takes two poles to produce a sine wave. If you divide 4 into 12 this gives you 3 poles per phase. Having an odd number of pole will give you 1 and a half sine wave per pole. Your orginal title had 16 poles which would give you equal poles for the 4 phases.
I might add that it is not the poles on the armature that will give you the 4 phases but the winding on the stator. Maybe this is what I am missing here to see just what you are trying to accomplish.
If you can clear this up for me, I might see it better.

Don
Title: Re: 16 pole 4 phase model generator.
Post by: old-and-broken on January 05, 2014, 04:52:44 PM
This was my idea of winding.  16 stator windings grouped 4 in a series with twelve magnet poles.

(http://picoolio.net/images/2014/01/05/Winding_layout.png)
Title: Re: 16 pole 4 phase model generator.
Post by: Don1966 on January 05, 2014, 05:06:54 PM
I can see it now and looks like you have done your homework also. The magnet oreitations are a nice touch. I need to study the magnet setup a little closer thought.
Are you just going to rectifier the AC to use?


Don
Title: Re: 16 pole 4 phase model generator.
Post by: Baron on January 05, 2014, 05:57:56 PM
Depending on the voltage generated and the power produced it could make a battery charger or with a suitable transformer step the voltage up to 110/120.  Stick the fan blade back on for a wind generator.  Now that's green ;-)

Title: Re: 16 pole 4 phase model generator.
Post by: old-and-broken on January 05, 2014, 06:22:04 PM
To be honest,  I did have the idea of putting the box fan back together and putting it all on the top of a tall pole in the back yard.   Should be able to produce enough current to charge some NiMH batteries and maybe use them for some outdoor cement pathway lighting.  When the wind blows that is. 
Title: Re: 16 pole 4 phase model generator.
Post by: airmodel on January 07, 2014, 11:46:56 PM
Very interesting project! I have made many model generators but have never rewound stators.
Title: Re: 16 pole 4 phase model generator.
Post by: PStechPaul on February 22, 2014, 09:48:55 PM
How is this project coming along? I think I see how the magnets and stator pole pairs work. At the point shown in your sketch, the N pole 1 is aligned with stator pole 1, S pole 4 with stator 5, N7 with stator 9, and S10 with stator 14, so you will get a voltage peak on the black winding (A) at this point (0 degrees).
 
Then there will be N3, S6, N9, S12 for a peak on the green winding (B).
 
Then S2, N5, S8, N11 for a peak on the blue winding (C).
 
Then N1, S4, N7, S10 for a peak on the red winding (D)
 
That would be 1/16 of a revolution, or 22.5 degrees. At this point the next sequence would be:
 
S12, N3, S6, N9 for a reverse peak on winding A. If I have understood this correctly, there will be four positive transitions followed by four negative transitions for each 1/4 turn, and four complete cycles per revolution.
 
I don't have much experience with generators, but with induction motors the winding pattern is much different, and usually there is overlap with belts that span at least three stator pole pieces, at least for three phase motors. The stators I have worked with have had 24 and 36 slots, and the maximum number of pole (pairs) would be 8 or 12. I rewound a couple of single phase motors for three phase, with much heavier wire, for a voltage of about 8 VAC, and then I used a VFD and step-down transformer to apply 240 Hz, at which point the 12 pole 600 RPM motor spun at 2400 RPM. It looked like this:
 
(http://pstech-inc.com/pictures/Motor_winding_320x240-01.jpg)
 
I actually made my own crude solid state three phase drive and was able to spin the motor using a 12V battery. But the MOSFETs were not properly rated and they released their "magic smoke".