This is my Epilog Laser Cutter entry so please Vote if you think the idea is unique and worth supporting.
Composting is the easiest thing one can do to help your community. With a wealth of good soil you, your neighbors, and everyone else is stuck with the predictament of what to grow. Imagine such a world.
The problem is that the standard composter doesn't turn itself, and the average human is too everwhelmed with life's callings to take the time to turn the composter once a week.
Hence the self turning composter, wind powered so no additional power is needed.
I just added a laundry basket to the inside to help churn the soil. It was turning a 3/4 full load with no problems at all. I had to empty it out to paint it black, but once the winds pick up I will post a video of it turning soil.
The gear drive supplies more torque than it would ever require, I used vise grips and tried to stop it turning but could not. I estimate that I applied about 150 lbs with a moment arm of 8 inches and still it didn't stop! The gear ratio is 1255:1.
You will need:
A drum, or other round item that will server such a purpose. Note that I did not have a drum but I did have a large bucket I bought for 3 bucks at walmart.
Plywood-depending on how big you want to go will determine how much scrap you need. I used about a half a sheet of 1/2 inch ply for the turbine but I think twice as many layers would be better.
2x4's or 2x6's-The frame and upright uses about 2-8ft lengths of one or the other.
Screws-get a box of 3in deck screws, they last forever and are very strong.
A junk gear motor with a high gear ratio is also needed.
Tools-I used a drill press, angle grinder, hammer, screw driver and jig saw. My advice, you can never have too many tools.
Time: It took about a day to make this. I actually did it over the weekend but actual time was about 12 hours.