The bearing motor

[tinman]

Current is flowing on the top disk from the rim to the center (left to right), and the bottom disk the current is flowing from the center to the rim (once again it is still flowing from left to right in the same direction as the top disk).  The current is flowing in the same direction through the same pole of the magnet for both disks.  This means the force is in the same direction for both disks.  Apply a force on the left side of the center of motion and it will rotate in the opposite direction than a force applied in the same direction on the right side of the center of motion.

Gravock

You have confused yourself with the position of the wires touching the disc in the video. The fact is,the two wires could be vertical to each other,and the two disc would still rotate in the same directions. So now all you have to do is move one wire 180* around the disc ,so as the two wires are now in a vertical plane. This will help with your confusion about the current flowing in the same direction. Now current is flowing in from left to right on the top disc,and flowing out from right to left on the bottom disc. The position of the two wires on the disc makes no difference to the direction of the discs rotation,unless the polarities are switched.

[tinman]

The 'only' thing I find incredibly interesting is the fact that the magnet can spin with the disk and produce currents in the disk. This is the one thing that should be experimented with to see what, if any, advantages that could be had, like the possibility of zero drag/lenz. 

So there are 2 possibilities for adventure here.  Either there is no drag, of which I think we can all appreciate, or, if there is drag, 'what ever we are dragging against', can that idea be used to cause motion through space with a solid state device.  Like a small device mounted on a small car, where the car moves by pushing or pulling against, 'what ever it is'.

Mags

And if there is drag/lenz, then what are we dragging against if the magnet is moving with the disk?

As i stated before,when the magnet moves with the disc,the lorentz force is against the magnetic field and the brushes/brush holders. When the magnets are stationary,then the lorentz force is between the rotating disc and the fixed magnet. This is why we need a setup where both brushes are on the shaft of the generator,and not on the outer perimeter of the disc.

[Magluvin]

This is why we need a setup where both brushes are on the shaft of the generator,and not on the outer perimeter of the disc.

Some magnet companies make custom magnets.  So if a tube magnet could be made, say N on the outside of the tube and S on the inside, then just have a copper tube that slides onto the tube magnet. Then we could just put the brushes on the ends of the copper tube to pull current or run as a motor.

Mags

[tinman]

Some magnet companies make custom magnets.  So if a tube magnet could be made, say N on the outside of the tube and S on the inside, then just have a copper tube that slides onto the tube magnet. Then we could just put the brushes on the ends of the copper tube to pull current or run as a motor.

Mags

No Mag's.
The last thing you want a homopolar generator to do is to work as a motor as well. The reason being that the motoring effect it self is what causes the CEMF when being used as a generator.

But your drum style homopolar generator may just work if it is consructed correctly. Although not as strong in field strength,we could use a stack of ferrite donut magnets from microwave ovens. It would still have to be designed so as the pickup brushes were on the shaft,and not the outer rim. So our shaft would have to be two pieces,and we use a teflon bush to join the two shaft halves together. The shaft would be best made from bronze,as it would be kinder to the brushes.

I have thrown together a quick sketch,and i believe that this design should give us two homopolar generators in one,with a series conection between the two. As we know,if we keep the same rotation direction,but switch magnetic field polarities,we reverse the flow of current. With this setup,we should get current flowing from one half of the shaft to the outer edge of the first copper disk(depending on rotation direction of course),and on the other side(other copper disk)we should get current flowing from the outer edge to the shaft. The copper tube that is around our magnets is our series connection cable between the two copper plates on either side of our magnets.

You will see i have placed a brush test point at the outer rim of the copper tube. This is there so as we can see if the amount of available power is due to tip speed of the brush in relation to the disc,or if only the RPM speed of the disc within the magnetic field is what produces current. We can also use this test point to see if we managed to reduce or remove the CEMF from the system.

Im not sure weather the design below will work?,but only one way to find out. We wont get a lot of power from it,as we are only using weak magnets,and in my setup,i will only have around a 2 1/2" diameter. but i do have some 20 000 RPM 12 volt motors here,so at that RPM we should get enough to do some testing with.

[tinman]

@ Mags

Here is a video that shows a similar setup. Im not sure what language it is,but this little setup puts out 30+ amps-->for a brief time. You will also see the back torque is quite high.

But rather that have the brushes on the outer rim of the disc's,my setup would have those two disc's joined in series across the outer rim of the disc's,and the shaft would be two half shaft's,and our pickup brushes would be placed on the shaft's. As i stated above,we wont get that sort of current,as i will be using much weaker magnets,and he seems to have some beefy neo's on that setup. But even if we get 500mA,that will be enough to do some testing and experimenting.

https://www.youtube.com/watch?v=A3vV5T4x-FI