A cutter assembly includes a rotatable cutting head carrying outwardly extending cutter blades, as well as a rotatable drive hub and interconnected spring housing. The drive hub has a bearing housing, whereas spring housing includes coil spring. The spring housing is operably coupled with the cutting head, in a manner such that the spring exerts an unrestrained force against the cutting head and blades so that there is unrestrained movement of these components toward the outlet face of an extruder die plate. Consequently, there is a substantially constant self-adjusting force exerted on the cutter and blades against the plate, which promotes cleaner cutting of extrudate, even in the event that there is a degree of misalignment between the cutting edges and the outer surface of die plate. This arrangement lengthens the service life of the blades and the die plate.