Mackay Dual Homo Polar Dynamo
I have put together a design for counter rotating magnets that work as two homopolar generators put in series. The problems I am encountering are the drive motors required to run it. The efficiency of today's motors is appalling to say the least. Also I have yet to do the transformers.
Tesla's patent https://www.google.com.au/patents/US406968 shows coupling 2 disks with an outer belt. Here I have coupled two disks with charge carrier type insulated wheel bearings that allow for improved construction features, easily obtainable parts as follows.

Coupeling / Asembelly allowing for increased modular configeration.
1. Compact vertical design allows for more stacked systems.
2. Limited increased cost for higher volatge output amps remain limited to conductor thickness.
3. Common use affordable stereo speaker magnets.
4. Low cost/ readily obtainable Aluminium conductor disks.
5. Insulated PVC pipe housing.
6. Recycled (rechargable drills as) drive motors.

After reading all of teslas available works I found two special mentions. One was for the Dynamo as he described "a curious machine he would come back to". The other phenomenon was Back EMF. I have banged together this first generator as a test model and thought it would be worth putting on the forum to see if anyone else is interested in the design. I am making mistakes with my lathe work and have excess friction etc that I need to overcome. I am also very dissapointed with the drive motors as they are an obsene waste of power to turn the disks. If I can draw the energy out anything like Bruce Depalma claims, it will be interesting to see and I will need all of it to pay for the drive motors.
I would definitely be using this as a central hub to make a large Whimshurst style generator if my wife lets me.
I still have a lot of testing to do but am surprised at it's simplicity and why no one else has attempted the same.
I could do with some advice on transformer coils to convert to a higher voltage for battery recharge.

The inner wheel / bearings that keep the disks apart and are used to turn the disks probably should be bigger. Mine are 50mm and I should have checked the magnets first to see how strong they would be pulling together at that distance. 80- 100 mm wheels may have been a better choice. I may try putting smaller magnets inside the existing ring magnets to try to increase the voltage that way. The suppliers largest ring magnets, currently using 2 of 145mm OD - 70mm ID x 20mmT. I started with 4 magnets and was double current voltage at same rpm. I reduced to 2 magnets because of close proximity only 10 mm apart should have been 50 mm apart. Gripping the wheels to much and slowing down.

Posted a short youtube video here https://youtu.be/Pgm9cvPPRIU
Red Collies post on Crop Circles and Homopolar Dynamos http://www.cropcircleconnector.com/anasazi/fringe2014s.html

I'll update this post as I complete testing and or the transformers etc.