Homopolar Generators (N-Machine) by Bruce de Palma

[keithturtle]

Thanks for that link.  I tried to maximize the magnetic surface area with my layout, but I fear the dissimilar sizes will create uneven field; kinda like flux in one spot reaching farther than flux in another.   Maybe it'll work "a little bit".

I dunno; it's gonna take a lot of turtlehours to machine out that base, and that's the one thing I have little of... time.

My base is that brown thick plastic you find in HV panel components; I chose it because the flux would not be compromised by a steel backing plate, and the mags will all be epoxied in their little slots.  Gotta read and see what these blokes used for a backing

Turtle, slow

[keithturtle]

I am still working with this as time allows; right now I am assembling the copper-aluminum-copper sandwich that will make up the actual rotor.  I bought some really stout 3x3x1/4" neos to create a field over just a section of the disk, rather than the full-area multi-magnet assembly, in the interest of time.

Turtle, working on it a few minutes a week

[keithturtle]

I've also given some consideration to the possibility of using thick pink foam, the 2" foundation insulation variety as the sandwich material.  If the flux reaction in the copper disk is all we are concerned with, why would it matter?   I have a couple brass flange collars to use as hubs.

With a greater separation of the N and S fields due to the greater gap (multiples of 2"), might that be an advantage?

The copper I am working with is 22 gauge, or about  0.030" thick.  It's all I could afford

Turtle, still at it

[tim123]

Does anyone know what happened to Keith and his research? It looked like an interesting and promising line of experimentation.

I have wondered about re-arranging the machine so the current runs axially instead of radially... I think it would make it easier to build. I can do a diagram if anyone's interested...

[mscoffman]

One problem these things have is that the individual magnet fields need to merge into a single
pole face field. If one simply sticks neodymium magnets to a metal disk the pole face is not unitary
and the face becomes a complex N/S pole mixture, with one pole squeezing through the other.
There is a youtube.com video where a person puts a plastic magnetic field diagnostic sheet
against a pole face configured in this way and the optical pattern shows that this occurs.
This simply means that a very low magnetic impedence return path (lower than free-space)
needs to be constructed so that only one pole transitions the gap between disks. Like a gaint
iron lamenent C. Experimenter's are loathe to create such a structure - hence their experiment's
homopolar don't work. You can see that a polar face mixture simply create an area on the
metal disk where the electrons spin in an eddy current loop contributing to lenz heating but not to
collective electron flow from center of the disk to the edges. Be ready to create a high magnetic flux
return path in homopolar instruments.