2 section centre pivot irragator
This is a project I made for homework. It is geared down 6-1 from the motor, one problem is that I couldn't work out how to attach the battery box to it so you have to carry it while the iragator is rotating. It has a bit of play in the axles, but it looks the part. The outside axle is driven via an overhead shaft from the motor. The other problem is that the platform isn't quite big enough and can topple over if you're not careful.