I created this stack of pulleys to drive a generator with this small wind turbine: https://www.thingiverse.com/thing:2755208
I printed two of them, one for the generator and one for the turbine, so I can test different transmission ratios.
I also uploaded the file for fusion 360 so you can modify if for you own needs.
PulleyStack.f3d | 175.8KB | |
PulleyStack6.6mm.stl | 1.1MB | |
PulleyStack8mm.stl | 1.1MB |