wind turbine

Far too many unknowns...
Are you talking about the blades? the electromagnetic circuit? the tower? braking/feathering system... 500w, 5kw? Vertical or horizontal axis? Shoe size.

You need to be more specific about what bits you are making and what bits you are buying and what you want to know.

Out of the great beneficence of my catly heart I'll give you this link, which has loads of good stuff, no charge, although if you have a spare sardine...
Del

F=MA

All else can be derived from there - if you're good enough.