This is my Three blade windmill design but with a gear end and gear-train. I also trimmed the blades to clear each other better. Don't print the gears from the file "windmill geartrain" it's just to show you how to mount them properly. The gear plates are the same but one has the mounting points labeled. There is no back plate yet. This is just the power unit. The blade pinion gear is available in two orientations. If your machine can't handle overhang but can do bridging use the upright one.