"Strange how things come in cycles, i mentioned the torus many times in the past but no interest ever happened, now everyone is looking at it."
Yes, talking about them and seeing pictures so we can fully understand it are two different things.
Flux (magnetic) was cheap, but now it's not, so easy alternators with cheap flux are no longer a cheap easy alternative. This means to get a decent unit, we need to do less of the easy, an more of the cheap.....
Chris has stimulated the ferrite idea, as he has shown that real power is a possibility. ( I can't stand the thought of rpm increasing devices 24/7) Now this torus type of alt promises sensible flux usage, and the possibility of decent power in a direct drive.... it has to inspire something.
I'm currently eyeing off a stack of microwave transformers. The "I" parts may lend themselves to messy, but useful stator plates. The short spans will create lots of reluctance, but even with myriads of end to end gaps (very tiny ones)... it may still be worth it.
Fixing the stator may not be that difficult if we use the fibreglass to protrude out the ends of the "triangular lands".... we could have 36 fixing points if we desire.
For folks in the states (USA) then south of the border is this
http://www.villaindustrias.com/catalogos/siliconsteel.htmlFor rule of thumb, what is the thickness of the steel stator. If I try this it will be 12mm or so (transformer lamination dependent) I assume the magnet covers three coils....
.................oztules