Dia. Mag. Alternator

[mscoffman]

So, now that I have the alternator plates deburred I can laminate the plates, and then start the assembly process.  I'm using a clear polyurethane paint for the "lamination".  I think I can build up several coats to get maybe 5 mils of space between the plates.  This is something that needs to be experimented with.  What is the optimum plate spacing?  Is there a maximum limit?  Could plate spacing make the difference between a normal alternator, and something exhibiting overunity?  Well, were gonna do about a thousand experiments to figure that out...

Here are the alternator plates in the laminating process...

@z.monkey

The optimal spacing is the minimum thickness coating of the insulation
that truly insulates the plates electrically. I would suggest that you
lightly deburr them and then rinse in a highly concentrated alcohol
solution. Then apply the coating. Stack two plates together and try
to measure the resistance between the plates from along their edges.
- no conduction means; all is well. Once you tighthen them into a
stack you may want to try the conductance test again but this time
with your utility voltage and a lamp. This will substitute for a HV
insulation test. If you get conductance simply take them apart
and reapply the coating. Since you are not currently doing RF
radio frequency work, the coating thickness is primarily to stop
conductance, while diluting magnetic characteristics of the core as
little as possible. No, It is not correct to look at the spacing as implying
a frequency of some type. It is to prevent spinning eddy currents
above a particular size. Yes, suppression of eddy currents contributes
to efficiency which is why it is used in LF AC motors. In HF AC, ferrite
binder materials insulate each particle of metal from the other, impling
3D eddy current suppression.

Your work is excellent mechanical work by the way.

:S:MarkSCoffman

[z.monkey]

Your work is excellent mechanical work by the way.

:S:MarkSCoffman

Thanks Mark,

I've been developing my machine skills over the summer, and its really starting to pay off.  Electric currents create magnetic fields, and we want to isolate the plates to prevent these stray currents from interfering with the intended flux pathways.  I do have a little problem there, there are 24 steel bolts that go all the way through the plates.  Uh, I guess I could use Nylon hardware.  And we have some more experimenting to do there...

The stray eddy current situation is somewhat analogous to trace impedance on a printed circuit board.  High speed digital design deals with signals on boards that run up into gigahertz frequencies these days.  To keep those signals clean your traces need to be tightly coupled to a reference plane, like 5 mils tight.  The problem with the eddy currents in the core material is similar in that these eddy currents can be considered to be noise, and we want to eliminate that noise, and isolation is the answer...

Testing the plate isolation is no problem.  I have the equipment already, and we can test it at various frequencies, both mechanically and electrically.  There will be an optimum operating frequency determined by the mechanical construct which, similar to audio resonant frequency, will result in the most efficient operation.  We have to figure out that frequency.  It will be somewhere from 50 to 400 Hertz.  We can use a variable speed motor and a tachometer to toy with the mechanical frequency.  50 Hertz would be 3000 RPM, and 400 Hertz would be 24000 RPM.  The bearings are rated up to 36000 RPM.

The next step is building the winding jig.  I have a tight space for the coils, and part of that space is open sided.  So I need to build a structure that can support the open sides.  I'll use a set of keepers, and glue the coil together so it will hold its form.  Then I need to modify the bearing plates to fit both the mounting plate, and the coils, and then we can assemble...

[z.monkey]

Cleaned everyone with Isopropanol...

Laminating now.  This stuff is stinky...

I'll be glad when this is done...

[z.monkey]

OK, now wrapping up the laminating process...

I am cutting the Winding Jig Blocks while I wait for the laminations to dry.
Then there is a pic of the cut Winding Jig Blocks.  The 4" trim saw was very
helpful in the process...

[z.monkey]

The finished stack thickness is 1.088 inches.  Before laminating the stack was 0.939 inches.  So, that works out to be about 9 mils isolation between each plate +/- 1 mils for inconsistencies.  The "lamination" paint that I picked first made very thin coatings, and I used the whole can on the top side.  The second can was a different source, and was a much thicker coating.  I only needed to apply two coats to the back side.  Then I shot the top side one more time.

Assembling the winding jig now...