On youtube we can find a interesting manual to make yourself a vertical axis turbine with plastic barrels. The author has been so successful that he even now runs a Online business where he sells a kit to install a turbine of this type, as well as a horizontal axis wind turbine and accessories for this type of project.
The project is based on 2 plastic drums of 200 liters. The kit for this vertical axis turbine includes the gear train necessary for its construction, as well as the Instructions in English or in Spanish.
If you are interested in this type of turbines, the tutorial videos and the kit it sells may be useful for your project.