@nomadicengi so I went to see if i could find some breakdown in energy costs of moving air directly versus moving the gears, and the web novel was different, in that he made two tools: the hair drier was the second, it was simpler (from google translate: "The parts are simple, only the case, the magic circle, the switch, the magic wire, and the magic output stone"), while the gears were used for a food processor (wind magic was supposed to move the blades directly, but it wasn't enough, so made the gears). i don't know why the manga combined both, and I don't know what the light novel did.