The generator will be driven by a pulley mounted on the engine flange. I started off with a piece of 7075 T6 aluminum of 25mm thick and 200mm in diameter. Since the jaw chucks of my lathe cant't clamp 200mm in diameter I had to drill first a center hole big enough to clamp it inside out.
I centered the spindle with an edge finder together with my newly installed DRO system on the mill. Required was a hole of about 43 mm. I also used a boring head to increase the inner diameter to make it fit the lathe.
