Some time back zubbly (RIP) sent TomW, one of the moderators of this board, a conversion of his ans told him to 'run it to destruction'. That was several years ago. To my knowledge, the mill is still running.

If you are not looking for extreme output, I think a 1/4 or 1/3 HP 3 phase motor could be converted to a PMA unit with the 'Ungrounded Lightening Rod' method of magnet placement and a blade-set with too many blades for top efficiency could be carved. Thus converted this motor would be a mill that is reasonable in cost to build, could be mass-converted and even have a bit larger bearings put in.

If you would be interested in doing this I could be persuaded to help design and even build them.