Axial Flux HELP!

[Karly]

I am making a small axial flux generator. I am having a really difficult time trying to get even one volt out of it...
If anyone could help me I would be eternally thankful!
I need a minimum of 12 volts produced

Here is what I have so far:

6 coils of 24 AWG magnetic wire
8 42 neodymium magnets, circular
Saw blade for rotor, 8" in diameter
Large screw as a dowell
plywood for stator base
nuts on either end of the saw blade

Each coil is wrapped by hand 150 times around a 1 inch thick piece of pvc pipe
The coils are NOT in a 3 phase, as I couldn't find a great explanation of how to do all of the connections
the Magnets are 3/4 in, and placed on the saw blade so that they pass through the 1 inch inside of the coils

So far, I have only been able to produce up to 0.05 Volts. I can't figure out what the problem is? Please help!

[electrondady1]

a photo or drawing of you layout would really help
it should do better than .05 volts .
I'm thinking things aren't laid out properly.
what is the thickness of the magnets?
the coils should be about the same thickness.
 have you checked the polarity of the mags ?
as in, north south north south etc?
what is the space between magnets ?
the space between the mags should be about the same as the width of the mag or slightly smaller.
the hole in your coils should be the same size as the mags or a little less.

you have turned 6 coils and have 8 poles that's the ratio of 3 phase
coil 1 in series with coil 4 . coil 2 with 5, and 3 with 6
if you want single phase you need to turn 2 more coils.

what sort of rpm are you turning this thing ?

[tanner0441]

Hi

You you have a saw blade for the rotor.  You don't mention anything on the other side of the stator for the magnet return flux path. A wiring diagram of the coil connections would be helpful and as mentioned are the magnets alternate N/S.

Brian
 

[Flux]

Check that your meter is set to read ac volts ( not dc)

There is a fundamental problem that may be causing most of the problem, 8 magnet 6 coil is basically a 3 phase configuration, if you are connecting everything in series to try to get single phase it should sum to zero. You can only effectively use the equivalent of two phases of a star winding ( 4 correctly placed coils).

Try measuring one coil, it should produce far more than you have at the moment.

Flux

[Karly]

Thank y'all so much for replying! I have made a few changes to the design...

I connected the 6 coils in a 3 phase star connection
I have added more magnets to more closely match the thickness of each coil
I have added rectifiers to accurately measure on the DC setting of the DMM

I am still only getting 0.40 volts. I am getting very frustrated because the setup follows others that I've seen, yet isn't producing any voltage.

I'm attaching photos of the current design I have, which isn't even producing one volt. Any help is welcomed and I appreciate the suggestions!!

[Flux]

Difficult to tell from your picture but you look to have a negligible amount of magnet. The other factor you don't mention is speed, how fast are you turning it.

With a single rotor with tiny magnets you will have to spin it fast to see much in the way of output.

Electricity doesn't come for free, you have to invest in a fair bit of magnet and make decent mechanical arrangements to really do much good. Your little set up looks ok as a first step learning experience but you need to take it way beyond that for a practical machine.

The other unknown factor is the distance from your magnets to the face of the coils, without some decent bearing arrangement you are unlikely to be able to keep that distance small.

Your coils look to be fine, as long as you have connected thenm correctly and in phase I think you are on the right lines ( you have a ten fold improvement over the first attempt)

The coil geometry doesn't look to be a good match for the magnet rotor as far as I can see from the picture.

Flux

[electrondady1]

don't get frustrated.
this stuff is tricky until you get on to it and then you will see it makes perfect sense.
you didn't tell us what  the purpose of your alternator is.
are you just curious or is this a school project.?
the reason i ask is you need to jig up a bit even to experiment.
you need a stable platform for your mag rotor to rotate .
use something like these
those coils need to be supported something like 2mm or 1/16th away from the surface of the mags.

i think the centre hole of your coils is too large
i wonder if the two coils you are using per phase are turned in the same direction, if they are perhaps cancelling each other out
you need to experiment with just one coil to get the maximum from each coil.

[tecker]

 Dad has some good advise ,hang in there . I don't see a good magnet spacing with this round large hole coils . Measure the Phases individually and see if you have a potential if so. Reset with a diagram from the Archives . 

[hiker]

place your mags farther out and your coils as well...heres one i did a few years back..