Hello,


For learning purposes, I have done a simple test with two doughnut magnets, polarized through thickness, and a long magnet as shown in the image "Equal and opposite torque".
The long magnet is forced to the right, but there are no sign of forces acting in the two doughnut magnets to make them turn around.
Reason is assumingly: When the force of the long magnet goes towards right, the long magnet also want to turn clockwise. This is an experiment I have done physically. Nothing happens to the round magnets. No spin, no torque. This is the only experiment I have done this far, on this particular setup.


So I think I will try to replace the long magnet with another smaller (approx half diameter of the larder ones) doughnut magnet that has one side polarized opposite, as shown in the image "What happens here 1".
The experiment will show me if that smaller doughnut magnet behave just as the long magnet, but if it will turn counterclockwise instead since it is on the inside of the larger doughnut magnets, AND wants to be forced to the right, just as the long magnet do - so the total forces points in the same, and not the opposite direction, to achieve torque. I want to learn why this possibly cannot work.


This is a test that will confirm what happens when we try to make a homopolar style motor with only permanent magnets.
A homo polar motor is basicly a conductive permanentmagnet attached to minus of a battery cell, and attach a wire between the plus and the magnet circumference (which is connected to minus via nickel plating on the magnet).
The magnetic field in the wire is circular and affect the field in the magnet so it will try to escape perpendicular to the circumference. This results in a rotary motion of the wire, or the magnet, depending on what style you make.


I will try to make a similar circular magnetic field between the two larger doughnut magnets, see image "What happens here 2". Since the small magnets curve away and inwards towards the hub, I want to check out how this will affect the forces, or possibly torque in the system.


Is it possible to achieve rotation with an all permanent magnet homopolar motor?
I think not. Possibly a waste of time, you might say, but I want to learn 

Green arrows are assumed forces if not specified otherwise.

Vidar

Here is a screen video taken from SketchUp Make. (I came across a function in Windows 10, which has the X-Box app. Pressing Win+G opens a recorder panel, and recorcds the active window :-))


https://youtu.be/wImS70Hqu0E


Vidar

I found the inventors website by google the name on one of the image-links.
http://mmmgroup2.altervista.org/e-magnet.html


Looks interesting. I have hundereds of neomagnets, and iron washers for the iron cores.
Forst an accurate simulation in FEMM. I suspect that the simulations made by the inventor are some what coarse. That will provide inaccurate data.


Vidar

Nice work, but please be careful.
There are closed rings in the schematic - you take a lot of single discs instead.
Maybe this could effect your draft.
Anyhow, good luck

Some progress

This experiment did not work. So I continued to research the reasons why a homopolar motor works.


I made a simple test with the traditional single wire. The magnet hangs in a screw.
I then went furter by making a coil with som 10-ish windings, and connected the wire ends like normal.


In the first part the magnet spins out of control as expected.
In the second part, with the coil, the magnet is so much more i fluenced by the electromagnetic field. So it starts to wobble heavily. Acts like a pendulum as the magnet tries to align with the much stronger electromagnetic field. It looses connection periodically and therfor swings back and forth.


I try to understand the magnetic connection the wire and the magnet has. I think I have figured it out.


South is pointing up, so the field goes ccw on right side and cw on the left side. The current throug the wire flows upwards and create a magnetic field ccw seen from above.


This will force the magnet to spin.


In my permanentmagnet experiment, this wire is replaced with magnets. Even if we would think it should work, and think a magnetic field is a magnetic field, they are not the same. Fields from an electromagnet is different. Because I cannot replace the electromagnet in a homopolar motor with a permanetmagnet that assumingly should do the same thing.


A video of the homopolar motor experiment:
https://youtu.be/Ca5KhC95owI


Vidar