First and foremost, you will need to invest a lot of effort reading, scrounging and building to do this. So far you have failed on the first 2.
There is no cookie cutter solution for using "junk" and the reason is the "junk" varies from place to place as do the skills of the builder.
Sorry you got took buying a car alt from someone who told you it would work [to make a sale].
Forget this kind of question until you have at least some clue of what you can do, what you can get in your trash stream, and what you need.
There you go, straight from the hip! Cheap is doable, free is unlikely. Both require a major commitment of time and energy. Thats just the turbine. Then you need cable, tower, batteries, controllers and inverter. None of those will be "easy" and certainly not "free".
If you cannot read and comprehend well, get someone to read it to you or find a text to speech software so the reading part is not an issue. Or, attend a workshop but that eliminates "free" as they all require money to attend.
This stuff is not rocket science but it is a bit involved. Not trying to discourage you just stating facts.
Reality strikes.
However, at the basic level many DC motors just need a prop to be wind generators. The prop could be anything from wood strips to plastic pipe. The mounting hardware could be anything almost. Depends.
Some of these guys here are true McGivers and could probably create a mill from a tube of toothpaste, a shoestring and a candle wick. I am not one of them.
Cheers.
TomW
