blutoy;
You do realize you get much more potential with bigger rotors over multiple rotors with same volume of magnet/etc?
At least that is the commonly accepted rule of thumb. I have no experience to substantiate that but just tossing it out there. I understand trying to avoid magnet rotors the size of manhole covers.
It looks like you are having fun so if you are happy so thats all good. Nice looking units, indeed. No intent to discourage you at all.
At some point your studs are going to get awfully long as you stack stators and rotors so curious how you feel about that bit?
Tom