An underwater pelletizer for extruding and cutting a process melt into pellets, comprising a pelletizer shaft (300) rotationally driven by a motor (390), a die plate (359) with a plurality of extrusion orifices formed therein, a rotary cutter blade assembly in opposed relation to said cutting face, said rotary cutter blade assembly having a cutter hub (350) with at least one blade (335) mounted thereon, a cutter hub drive mechanism, a cutting chamber (355) enclosing said cutting face and cutter blade assembly. A quick disconnect hub (320) is configured to removably couple the pelletizer shaft to the cutter hub holder (315), wherein a separable connection between said quick disconnect hub (320) and the pelletizer shaft (300) is configured to allow for separating the pelletizer shaft from the cutter hub holder.