That reminded me-I stripped out a big industrial exhast fan out of the building I'm working on, thinking I could make something cool out of the fan. Its about 30" wide with 6 big heavy aluminum blades on a shaft with 2 bearings. Well, the thing sat in the garage for awhile then one day it was fairly windy, so I grabbed the thing by those 2 bearings just to see if it would spin. It started out slow, but after just a few seconds the thing was doing about a thousand RPM and I figured I'd better step back out of the wind. As soon as I moved, gyroscopic or centrifugal or whatever took over and spun the fool thing around and into my leg. It cut thru my carhart bibs and put a fair sized gash in my leg before I could turn it loose. Now I think I'll hook it up to a generator instead of a wind chime!