i recently got a small cnc mill, but it didnt come with a air assiat or any type of cooling.
i thus made a fan (Idea from Carbide3d) that easily fits om the endmill schaft and due to it spinning upto 24000rep produces enough wind to get rid of chips in the cutting area, this prevents recutting of chips, heat build ups and broken endmills, especially usefull in slots and pockets