Fieldlines.com || Make your electricity from scratch!

Front Page - [Homebrewed Electricity-- (wind) (solar) (hydro) (steam) (controls) (storage) (mechanical)] - Classifieds - Site News
Everything - Newbies - [Remote Living-- (housing) (heat) (light) (water)] - Reviews - Diaries - Our Products

4pole radial...
By windstuffnow, Section Homebrewed Electricity Posted on Mon Oct 16, 2006 at 02:43:50 AM MST
similar to WXYZcience ....

Well Joseph... now you did it... the tube alternator definately has some potential. I changed the wire loom to become a part of the case to help speed things up on assembly. I started by making a pattern and taped it to the plastic which would become the front and rear covers...

Then simply drilled the plastic. This one I used some 1/4" bearings since it was going to have a rotor with a little weight. The magnets were mounted on a solid square 1 x 1 steel block with a 1/4" hole drilled through the center. Below is a shot of the parts cut and ready to assemble...

Below the magnet rotor and case is assembled...

Finally, it's all wired...

I used 40 turns of #19 wire, although, I wish I had used #22 instead to get more turns in the holes. The holes are 1/2" diameter and it was a pain in the fingers to get 80 wires in each hole.
I set it up in star and gave it a finger spin and ended up with around 11 volts at I'm guessing around 300-400 rpm. In star it measured 2.3 ohms between 2 output leads so I'm guessing it would do fairly well in the 700+ rpm range. A short circuit reading of close to 7 amps on the end of my drill.
I'm ready to build an 8 inch diameter radial now ! With what I learned from this little one a larger one will definately pack a punch. The 8" will have 24 poles and 72 coils. This should keep the turn per coil count low and close to the magnets.
Joseph is definately on to something here ! I had to put my other alternator projects aside to put this little one together today... now I have to build another one.
One other idea I had... thinking of making a mount for this one was to use a sheet metal case which would help draw the flux through the coils. It's far enough away from the magnets to help yet not cause to much drag or eddy currents. I'll finish up the mount tomorrow and see if it causes any problems...
.

4pole radial... | 28 comments (28 topical)

Re: 4pole radial... (3.00 / 0) (#1)
by ibedonc on Sun Oct 15, 2006 at 08:56:42 PM MST

wow that is nice , I want a big one , I am going to 96v or higher on my gens

and use a buck converter to batteries ( 96v bank ) you loose a lot of watts on low voltage systems

Re: 4pole radial... (3.00 / 0) (#2)
by WXYZCIENCE on Sun Oct 15, 2006 at 09:53:45 PM MST

Thanks Ed for the plug. Joined the RACA Air Core. I may have to change direction just a little, backtrack after seeing your answer to wires crossing.

Joseph.

Re: 4pole radial... (3.00 / 0) (#3)
by WXYZCIENCE on Sun Oct 15, 2006 at 10:00:29 PM MST

Ed, did you even get any sleep between building your 3 pole to this 4 pole one?

[ Parent ]

Re: 4pole radial... (3.00 / 0) (#4)
by windstuffnow on Sun Oct 15, 2006 at 10:32:13 PM MST

Joseph, I did get some sleep... This one only took a few hours to actually get the parts cut out. The winding probably took the longest.

I was quite surprised to see the average gauss in the air gap to be around 2000, I expected to see it a bit lower. With lots of coils and low turns for closer clearance's I think that could be raised to close to 4000 possibly higher. I'm reading 4900 at the surface. I've built some pretty good performers with ceramic magnets and they only pack around 1200. This has some potential to make a pretty powerful "no cog" alernator.

Another nice thing about it you can use lots of poles in a small area dramatically increasing the magnetic area exposed to the coils. What you don't have in gauss is more than made up for in area.

Poking some numbers into my spread sheet with the data I gathered from the small one I think I could do a 24 pole with 12 turns per coil for a cut in at 80 rpm. Haven't worked out the details for wire size yet... back to the drawing board for an 8 inch model...

.
Have Fun! Windstuff Ed
[ Parent ]

Re: 4pole radial... (3.00 / 0) (#5)
by Flux on Mon Oct 16, 2006 at 03:22:01 AM MST

As with axials, the main way to increase output is to increase diameter.

The simple form with no return path will likely suit small machines but to get reasonable output you need a flux return path.

This machine has a smooth iron stator outside the coils to complete the flux path, it was a motor core with the teeth removed. the rotor is a 16 pole and the coils are wound as an overlapped winding in the air gap between rotor and stator.

Iron loss is low and there is no problem with thrust as in its axial equivalent.

I did this one to suit an available rotor. I prefer to spin the magnets outside and wind the coils on a smooth core inside. ( brake drum type design).

Large versions of the type you are playing with will be tricky to mount without cogging or inducing eddy currents into the mounting.

Nice work, keep experimenting and having fun .

Flux

[ Parent ]

Re: 4pole radial... (3.00 / 0) (#16)
by willib on Mon Oct 16, 2006 at 11:08:52 AM MST

Love the symetry of this one Ed, its beautiful.
What you and joe(wxyzscience) are doing is really exciting, is there any play in the shaft , if you were to push and pull on it ?
i have a rotor that i did a while back , just waiting for this to happen.
it was from a automotive fan/blower motor , what i did was i was only able to get two coils INSIDE the housing of the fan motor, between the housing and the rotor.
now i see the i dont even need the housing , just the bearings and two plastic end plates , with holes for coils.
i think it has six poles on the rotor .i still have to locate it..
i doubled up 12 ,1"x1/2"x1/8" mags ,
i cant wait to try this out ...

Carpe Ventum (seize the wind) One needs faith in the future
[ Parent ]

Re: 4pole radial... (3.00 / 0) (#6)
by nothing to lose on Mon Oct 16, 2006 at 04:13:46 AM MST

I like that, but isn't it kinda like a motor conversion without laminates (teeth).
Would arced magnets work better? I still have a few #29 and could get other sizes.
E-mail me if you want to try arcs.

Well you did it now, got me off into another round of project thinking for something else, raining hard here anyway again, no outdoor work today.
I wonder if I have motors to unwind with near correct sized wire?
What are you using for the plastic ends, would cast epoxy in a mold work as well,
.
nothing to lose

Spelin and tpying are my strong points, not electronics.

Re: 4pole radial... (3.00 / 0) (#8)
by Flux on Mon Oct 16, 2006 at 06:42:22 AM MST

Yes it is effectively a motor conversion without teeth.

The arc magnets would be excellent, especially if the curvature suited about 12" diameter.

Starting from scratch it is far easier to spin the magnets outside a smooth laminated core. No need to remove teeth and it is much easier to fix the coils on the outside of a cylinder rather than inside.

It's not a beginners project, you need to be able to make a drum for the magnets and it is not an easy thing to wind, but for those who can do it, I personally think it is an excellent way to go.

Iron loss is very low, cog doesn't exist, magnets are not thrown off and the windings are in direct contact with the core and cooling is excellent.
Flux

[ Parent ]

Re: 4pole radial... (3.00 / 0) (#7)
by DaveW on Mon Oct 16, 2006 at 05:28:50 AM MST

Darn it, people, I almost had caught up, and now this. Looks simple enough to play with, and I have small bearings in my junk box, and scrap Delrin, oh well, it is raining and the bench is almost clear.
DaveW

Re: 4pole radial... (3.00 / 0) (#9)
by tecker on Mon Oct 16, 2006 at 07:23:54 AM MST

The flux from this rotor would match somewhat with arcs sweeping from the flat face to
the ends and oposite face with the largest sweep comming from the center of each face to the edges maybe slide a steelcylinder over the outside and see if the output increases.

Re: 4pole radial... (3.00 / 0) (#10)
by wayne on Mon Oct 16, 2006 at 08:25:17 AM MST

You did it again and what great work. I really like this method vs the outside loops on outside on tube. I am using 4" PVC right now and hope to make end plates tonight. The rotor is done for now. A 8" should be even better. I think this could be a new future alternator's and so much to learn. Don't go to fast, just joking!

Wayne

Re: 4pole radial... (3.00 / 0) (#11)
by windstuffnow on Mon Oct 16, 2006 at 09:22:28 AM MST

I was playing around this morning and wired it to the three phase doubler and it's actually quite impressive. With my drill clamped to the shaft the open voltage was just over 40 volts around 750 rpm. Connected the outputs to my battery and it did a nice 2 amps while bogging the heck out of my drill... didn't get an rpm speed but I will sometime today.

If I had known it was going to perform this well I would have done a few things different. Since it's wired there is no way of getting inside it now without unwinding it. I should have made the shaft longer to protrude beyond the wires a bit and a larger shaft and bearings would have made it perfect. There is enough room to put a hub on the 1/4" shaft but doesn't offer a huge amount of strength. It actually makes to much power for my stirling project but I'll find a use for it.

My 3 phase doubler, I don't really know if that's what it would be called but I was looking at the doubler circuits and wondered if there was a way to connect all 3 AC output wires into it and it dawned on me to remove the diodes and use a rectifier in their place. Well, it worked and very well I might add. I've tried it on a couple projects and even connected it to my rooftop L2 turbine. My rooftop alternator cuts in normally at 100 rpm but with the doubler it starts chargine 12v at 30 rpm ( little more than double actually ). It gives me a cut in speed of around 4mph although the power is very low at that speed and is doing an amp by 7mph. I'm using 2 1800uf caps rated at 80 volts and a 35amp rectifier for my test circuit. I have 2 1F caps on my rooftop circuit rated at 24 volts so you don't want to disconnect it from the battery while connected to the turbine.

Ok, so here is a quickie drawing of the circuit and those that know more than I about electronics could explain it better please do!

.
Have Fun! Windstuff Ed

Re: 4pole radial... (3.00 / 0) (#12)
by Flux on Mon Oct 16, 2006 at 10:11:06 AM MST

That is where a limited electrical knowledge helps. I would never have tried that.

It behaves somewhat like the 3 unbalanced windings of the Air 303. At low speed the doubler on the bottom phase will start charging. At higher speed the phase connected to the bridge will produce most of the power but some will still come via the boost circuit.

Never a balanced load and perhaps not desperately high alternator efficiency but you may still come out better with the prop running at a better speed. Prop matching is as important as absolute electrical efficiency. I wouldn't scale it up to large machines but for low power it may be a good idea.
Flux

[ Parent ]

Re: 4pole radial... (3.00 / 0) (#13)
by windstuffnow on Mon Oct 16, 2006 at 10:34:48 AM MST

Thanks flux for clarifying it a bit better. On my roof top I have the turbine connected to the normal 2 rectifier circuit. I added this circuit as a separate circuit in parallel with the normal circuit. It seems to work fairly well, the highest I've ever seen from the turbine was 30 amps in storm conditions and most of the time it runs in the area of 0-10 amps. Summer winds are real low here and this thing is almost always adding something to the batteries with the doubler in place.

.
Have Fun! Windstuff Ed
[ Parent ]

Re: 4pole radial... (3.00 / 0) (#14)
by wayne on Mon Oct 16, 2006 at 10:50:49 AM MST

Thats really different and will have to test this out. On your plastic stator I wired it up as 2 phase, then had the seperate bridge for each phase. Then had caps on the D.C output, then wired the output like a battery. Seemed to work to raise the voltage. I don't know under load what would happen. I uploaded my latest stator in my files, it looks crazy! These are only test wires and not real yet.

Wayne

[ Parent ]

Re: 4pole radial... (3.00 / 0) (#22)
by vawtman on Mon Oct 16, 2006 at 05:40:18 PM MST

Hello Ed and nice job once again.
Wouldnt it be cool to have the stator stationary and the mags(arcs) on a motor rotor and against the housing?You would have to cut off the mounting.
Sorta like a radial axial flux.

With the lams removed from a stock motor you could put mags on the stock rotor(without turning}and mags on the inside of the frame you would need to customize the endbells somehow but could be done.The stator could mounted to additional bearings on the shaft.Maybe?

I know im way out there somewhere.

Could a pipe with inner mags somehow attach to your design ?

[ Parent ]

Re: 4pole radial... (3.00 / 0) (#15)
by powerbuoy on Mon Oct 16, 2006 at 11:04:27 AM MST

Ed:

Place it into a steel tube ... it should now work even better since the tube will provide a return path for the flux.

Powerbuoy

Re: 4pole radial... (3.00 / 0) (#17)
by hvirtane on Mon Oct 16, 2006 at 11:17:14 AM MST

Really nice.

Why not a steel tube outside turning
with magnet rotor?

- Hannu

Re: 4pole radial... (3.00 / 0) (#18)
by kitno455 on Mon Oct 16, 2006 at 01:24:48 PM MST

my thoughts exactly. a press fit plastic disk on one end of the shaft, a bit of iron pipe pressed onto that. you would likely then want another bearing on that end, or you have to cantelever the entire thing.

should be possible to do this with any induction motor rotor, without turning it down, just grind some flats on it.

are the coils going to vibrate if they are not potted?

allan

[ Parent ]

Re: 4pole radial... (3.00 / 0) (#19)
by powerbuoy on Mon Oct 16, 2006 at 02:07:36 PM MST

Another thought ... you'll need to find a way to fix the wires. Having them loose between the two plastic discs will not do you any good in the long run. There will be forces acting on the wires as soon as you start pulling some amps.

Re: 4pole radial... (3.00 / 0) (#20)
by tecker on Mon Oct 16, 2006 at 03:53:33 PM MST

Yep they will have to be encapsulated they'll vibrate the insulation off .

Re: 4pole radial... (3.00 / 0) (#21)
by tecker on Mon Oct 16, 2006 at 04:10:03 PM MST

It looks really good but it's going to have problems . Might be a good device for a Zub style cage as the attraction plus movement will scamble the mags

[ Parent ]

Re: 4pole radial... (3.00 / 0) (#23)
by RP on Mon Oct 16, 2006 at 10:19:38 PM MST

Let's brainstorm a bit on a source for thin metal rings to act as a flux return path outside the stator.

Let's see, we need the equivalent of a stack of giant steel washers or soemthing like it.

Hey, what about making a spool of painted iron wire like they use for arts and crafts (and flower arranging)? If you spooled the wire about 1/4" thick in a big solenoid around the stator it should minimize the eddy currents but still assist with the flux path. I suppose you could even pot it onto the stator itself for additional support.

Say about 10 pounds of 18 guage iron wire turned right over the copper stator wires and then potted in resin. If the wire had mill scale on it then it probabaly wouldn't even need paint as an insulator. The disadvantage of direct potting would be difficulty of rewinding the stator if needed but you'd sure have the minimum possible flux path without cogging.

I wonder if the iron winding would also help to remove heat from the copper?

Re: 4pole radial... (3.00 / 0) (#24)
by willib on Mon Oct 16, 2006 at 10:50:24 PM MST

With my 6 pole rotor i can make 18 coils at 60 degrees apart.
with the coils 60 degrees apart it should save on resistance a little.

also i found 2 bearings that fit the shaft perfectly :-)

Carpe Ventum (seize the wind) One needs faith in the future

Re: 4pole radial... (3.00 / 0) (#25)
by jlt on Tue Oct 17, 2006 at 04:30:44 AM MST

these are some of my past experments. with a radial alt.i only have 2 photos of it left. it was made from a wheel from a chevy pu.i used a plywood core with some steel wire wownd on it and the coils glued to that .then i tryed it with a cast stator core made from resin and iron filings.i only had one test coil on that one.the iron core was acting like the windings were shorted out. i could hardly turn it.worked much better with the ply wood,wire stator.it was only single phaze. i couldnt figure out three phaze at that time.i wish that i had kept it around abd tryed some neo,s on it.i think it would have made a good alt .i got info on axiel. alt,s at that time so i junked.it and went to them.

Re: 4pole radial... (3.00 / 0) (#26)
by WXYZCIENCE on Tue Oct 17, 2006 at 10:15:38 AM MST

jtl, were the magnets on that one ceramic. I have some that look the same. They may be a dual magnet, split through the center. They would have canceled each other out and been real hard to turn.

Just an idea, Joseph.

[ Parent ]

Re: 4pole radial... (3.00 / 0) (#27)
by jlt on Tue Oct 17, 2006 at 01:15:17 PM MST

no they were lowes magnets they worked fine with the plywood wire stator core. it was the other core made from iron filings . that made it hard to turn.

[ Parent ]

Re: 4pole radial... (3.00 / 0) (#28)
by spinner on Fri Oct 27, 2006 at 08:13:45 AM MST

gotta love yer approach!
looks like something that someone like me, WITHOUT machine shop capability could experiment with;ain't that what this site is about?
spinner

[ Parent ]

4pole radial... | 28 comments (28 topical)

Menu

� create account
� How to use the board
� FAQs
� search the board
� Google search the board

Login

Make a new account

Username:

Password:

Total Views

��236 Scoop users have viewed this posting.

Related Links

� magnet
� Also by windstuffnow

You must be a registered user to post here. It's easy and free, and the link is on the upper right side of your page.
All trademarks and copyrights on this page are owned by their respective companies. Postings are owned by the poster, but may be deleted or moved at the ADMIN's sole discretion. The Rest � 2009 Forcefield.
You can Email the board ADMIN here. PLEASE include the username you signed up with!