Abstract: Injection molded plastic pulleys (10) reinforced with glass fibers (at least 15 weight percent) are provided which exhibit low levels of out-of-roundness. The low levels of out-of-roundness can be achieved without the need for machining through the use of disc gating and perimeter venting. The pulleys (10) have belt-engaging surfaces (15) whose out-of-roundness is less than or equal to 35 microns when measured at any location up to 1 millimeter from the outside edges (16) of the belt-engaging surface (15).

Abstract: A modular molding system having: an upper frame assembly configured for receiving a cavity module therein; a lower frame assembly configured for receiving a core module therein, the lower frame assembly including a two-stage master ejector system; a cavity module positioned within the upper frame assembly; and a core module positioned within the lower frame assembly, the core module including a two-stage ejector system having a plurality of ejection elements associated therewith; wherein the core and cavity modules together define a molding cavity for molding a workpiece therein, and wherein the master ejector system is operable to drive the ejection elements of the core module.