I designed this customizable propeller file for my Mini Underwater ROV project but these propellers can be used for anything from RC boats to fan blades.
You can customize everything from size to shape to your liking using the customizer app.
I also uploaded 2 stl files designed for a 2mm motor shaft. The first propeller has a 40mm total diameter and the second is 50mm.
I printed my propellers in white PETG filament.