I ordered my magnets from https://www.xump.com/Science/BarMagnet.cfm, 50 cents is really cheap, and i need a lot of them. I decided to go for the blue one in the details. I was going to drill a hole in the middle of 8 magnets, and bolt them to a piece of plastic in a circle. Cut the middle one in half, it won't affect the polarity. Countersink a hole for the rod, and attach it to the magnet. Hold the rod in place and leave it room to spin. I'm pretty certian it should work, now to research waterwheels..