What happened with the minigen that you ordered??
Let me take your questions in the order you asked them---
coil inside diameter--as you were told in previous postings, the same as your
magnets or smaller
coil outside diameter--depends on the gauge of wire and number of wraps
coil thickness--generally the same thickness as your magnets
wire gauge--depends on what you want to get out of the generator
number of turns--depends on what you want to get out of the generator
etc.---
As you can see, you haven't given enough information for anyone to help you.
I really suggest that you read and reread everything you can find on wind
generators. You said in your initial posting that you had downloaded Hugh's
booklet on PMA's. Read it. Also get Hugh's other books and study them (Windpower
Workshop and/or How to Build a Wind Turbine). At approx. $20 each (US), they
will be the best investment you can make if you are to continue with this
disease/madness of building wind generators. BTW, they are not his only books!
The best path for people just starting this madness is to follow someone
else's plans (step by step) for the first 1 or 2 generators. It really helps
get a better understanding of what is going on and how things interact with
each other. Going off on your own and experimenting is to be applauded---
once you have the basic knowledge and understanding of electricity and
generation.
I'm not trying to "chew you out" or embarrass you. If I have offended you,
that was not my intention. I just think you're trying to move too fast,
and you are not "listening"/understanding what people are telling you.
Russ just told you yesterday--
"Here are some of the factors that go into making a generator with wire and moving magnets.
You want the magnet path to be perpendicular to the wire
You want to avoid cancellation by ensuring that the two "legs" of the coil never see the same magnet pole at the same time
You want to maximize voltage by ensuring that the two legs DO see opposite poles at the same time (one leg seeing a north pole while the other sees a south)
You want as many turns as needed to achieve the desired voltage/rpm.
You want the thickest wire you can fit to minimize resistance.
You want the thickness of the stator (for air core axials) to be as thin as possible to have maximum flux between the rotors.
When you add these to the various shapes of available magnets, you end up with a variety of coil shapes each with its own set of compromises."
Look at the 4th "You Want" from the top. And today you're asking the same question
again. 
??
Ralph
