So I want to try to create my polyphase using the Clemente Figuera resistor method, as it accomplishes everything I want. But I want to avoid the drastic steps between the resistors, that cause the stepped sine wave. So I have been thinking about it for a while, and I have an experiment to try.
If we could make a liquid resistor rig, the commutator could be a standard piece of copper that rotates through the liquid. Then the resistance will gradually change as the rotation occurs, as opposed to using jumping contacts which causes stair-like waves.
So I am going to try to print out a toroidal shaped container which shall contain a liquid resistor. I will be trying to use a slurry as a liquid to prevent splashing. My first attempt is I plan to use a conductive powder such as iron powder, mixed with mineral oil to create the slurry. Slurry. Mineral oil should allow conduction, and also prevent any oxidation or rust to form. It should also not evaporate.
The individual conductors that connect to electromagnets will be placed into the slurry on the outside perimeter. Then on the inside perimeter of the toroidal liquid resistor, I shall rotate positive direct current which will travel through a piece of copper and into the slurry.
This should create different resistance points, because of the variation of space at any moment between an individual contact and the power within the slurry. The slurry can be adjusted to attain proper resistance levels by altering the amount of conductive iron power that is used in the slurry.
I have not verified any of this, this is a brand new idea. But this may provide a way to replicate the Figuera resistor rig, but in a manner which does not wear down the brush, and hopefully operate in a manner which produces a smooth wave which eliminates the steps and jump in resistance that the regular resistance rig does.
It should be a rather easy test, so I will start printing tonight.