Dear lookrent, I'm still fairly new, but from my research, the magnets should have a steel backing thick enough that a metal paperclip held to the back of it will not stick.
After completing an axial-flux wind-gen, it is also apparently useful to be able to adjust the air-gap to use the optimum setting for your particular type of wind.
Spacing the magnets farther away from the stator will allow it to start spinning in a lighter wind, but it will make less power once spinning.
Adjusting the gap closer (where the magnet field [flux?] is stronger), it will make more power once spinning, but will require a stronger wind to get it to start-up.
If you already have a heavy truck fan clutch and would like to try this, please take pictures and post the results, as even a weak wind-gen can be informative for other new enthusiasts.
The multi-bladed radiator fan has been tried, and even a modest and simple 3-blade with longer more slender blades will produce more power (or so I'm told)
