This wind generator uses 3D printed blades that could scaled down using a program that can resize STL files. Each is printed upright, really the only way to do it, then attached to a hub. You will have to redesign the hub. The cost to print the parts is negligible so you could experiment with different sizes and pitch. You could also experiment with different prop shapes. Includes STL and G-Code files:

https://www.instructables.com/WINTUR...ger-Wind-Turb/