Abstract: A molding device is provided for molding a blower fan that has a center member embedded in a center portion of the fan. The molding device comprises a pair of molding dies which define therebetween a shaped cavity when properly coupled; and an insert die fixed to one of the pair of molding dies in such a manner that at least a part of the insert die is exposed to a shaped cavity that is produced when the molding dies are coupled. The insert die includes a base block secured to one of the pair of molding dies; a cylindrical holding bore defined by the base block; a plurality of cylindrical eccentric members having eccentric through bores whose eccentric degrees are different from one another, each eccentric member being sized to be intimately received in the cylindrical holding bore; a positioning structure that establishes angular positioning of the cylindrical eccentric members.