My dear friend and supporter Monty made a suggestion about my small rail gun prototype at http://maginvent.com/2016/04/13/rail-gun-magnetic-drive-possibility/
After his comments, I went back and considered the possibility even though I hadn’t even built the first one yet. Basically what he said was “You might want to place your drive magnets in a slight arc also.”
So I made the wheel about 12″ in diameter and arched each bar magnet at 10º. Just a beginning thought. I still need to build the first one, if not just for kicks and giggles.