Sammy, am I correct in that you are thinking of a single magnet rotor with coils on top of laminates versus the same with coils in a slotted laminate? If so, a while back there were numbers posted with a great increase in amps out with the slotted design. I thought it was either Ed at windstuff or Rob D. that provided us with the numbers. I checked back, but unfortunately couldn't find the posts. Perhaps someone else gave the info. Hopefully someone with a better memory can find the link to the numbers given. Most think of "air core" being a two magnet rotor with a stator between them... Gary D.