This Lego Technic MOC has over a billion to 1 gearing ratio. It is designed to resemble an architectural tower structure. I measured the input speed of over 3000 RPM using a digital tachometer and calculate the rate of rotation of the tower top to be about 222 days per rotation. This design has no purpose what so ever other than to look good and make a lot of noise. This idea was suggested and inspired by one of the eurobricks contributors.