14-11 stator update.

[Jerry]

I must say I'm very happy.  I asembled the 14-11 PMA today.

All but the coils. This was to test the effect of placing a mixture of powdered iron dust/residue from a brake drum/disc laithe in the coil centers.

I mixed about 25%? iron dust with fiberglass reson into stator disc set up for 11  coils.

I cut 11 openings of 1-7/8" X 7/8" X 1/2". The 2 steel discs I'm using are 12" dia. X 1/4" thic. There are 14 ceramic magnets of 1-7/8" X 7/8" X 3/8" on each disc.

I have not wound the coils yet. This is simply a test for cogging.

I'm very pleased to report the cogging is extreamly small. All most none existant.

The shaft in this unit is 3/4" and at the prop  end reduces to 5/8".

The stators spin very easy with just using my thumb and for finger on the 5/8" shaft.

I've stood below wind generators spinning up in the wind and have heared that distinctive growl from the magnets passing by the coils.

I hear the same but very faint sound when this unit is spun up at a high enough speed.

I can tell from this there is some atraction of the magnets to the iron.

I did a magnet test befor I assembled this unit.

Using this stator I placed a ceramic magnet on either side of the iron portion. They stuck.

I move'd the magnets away from the iron part and they fall off. NEOS would not fall off. There stringth would work and hold in a none iron gap much wider then this.

So I'm helping these weak magnets without introducing a detrementle amount of cogging.

Next I'll cut the test iron out of this stator form, wind the coils, cast the iron in the center of the coils and the reason over the top and outsides of the coils.

I'm wandering if there should be diferant wire ga. and turns count in the stator I'm building without the iron?

Here are a few picturs.

 

This is the front of the PMA. You can see the back side of the magnet disc and a magnet and the iron part in the staor just below.

Here is a closeup.

Here is a few veiws of the complete PMA.

Here is a picture of the stator unfinished. I'm test fittinf 4 of the 44 each 6 amp diodes the will be directly mounted to this stator .

More updates on the test #s soon I hope?

                          JK TAS Jerry

[hiker]

do you plan on using neos--after your test?

that is if every thing goes as planed........

[Jerry]

Hi hiker.

Not in this one. This will fly with ceramics. I'm building a 10" dual rotor with Eds wedge NEOS.

However I'll not use iron with NEOs. But it will be "Jerry Rigged" and maybe with the small diodes on the stator form as in the picture above.

One more thing about the cogging in the unit above. When I spin it up by hand it continues to spin for a while and gradualy slow down. When it finanly stops it jigles back and forth as it settles over a magnet. This also shows the iron is regestering and has a small influence.

                          JK TAS Jerry

[ncblue]

tis a thing of beauty. gives me some ideas for future construction.

got a couple questions.

coil to magnet gap?

size of wire and # of turns?

those look like 1x2x.5 ceramics, i got a ton of those and they are pretty strong for ceramic.

[Jerry]

Hi ncblue.

The space between the coil and magnet may end up around 1/16".

The first ceramic dual rotor alt I built using 24 ga. wire at 300 turns per coil.

Each coil had its own fullwave bridge rectifier. All the DC output of the bridges were wired perelell (Jerry Rigged).

I'm building 3 stators to try in this unit.

 1. as the original 300 turns 24 ga. no iron center, 1/2" thick startor.

 2. as many turns will fit 22 ga. iron in the center, 1/2" thick stator.

 3. is 3/8" thick no iron and not decided on ga. and turns count yet?

It won't make much power but I hope to see early cutin?

                        JK TAS Jerry

[ncblue]

thanks

knowledge is a wonderful thing