Hi,
I cant help but agree that buying almost anything would be MUCH simpler and
faster than trying to build a practical generator at home unless you happen to
have a machine shop too.
There is much more to this than we might think at first, and part of that is
that this is a highly intricate mechanical problem as well as electrical.
Commercial generators have concave shape magnets, and convex shaped
armature laminations that match and mate to keep gap distance small. This
would be hard to do by hand.
For winding the turns you would have to use some kind of special bobbin or
else come up with something that would work like that so that the wire doesnt
contact the armature laminations directly.
The only reason people usually ever build their own generators is when they are
studying this stuff and just want something to act as a real life model to show
that it can be done, but these little things are definitely not practical in that
they are too inefficient as well as too small anyway.
I am not saying that it can not be done, just that it will be very hard to do and
unless you can get the shapes right there is a very good chance that it wont
be very efficient and you wont be happy with it for the money you have to
put out for the parts. Wire itself will run around 100 dollars if you are lucky.
The basic formula is the bigger the better. The strongest magnets you can find,
the biggest armature you can build.