the cutter hub alters the axial spacing between the first cutter ring and the second cutter ring resulting in alteration of the spacing of the cutters located thereon reorientation of the first cutter ring and or the second cutter ring is accomplished by reversing the orientation of the one cutter ring with respect to the other varying the number of spacers which locate and brace the first cutter ring and second cutter ring on the cutter hub and or varying the relative widths of the spacers application_number US 84825992 A description referring to fig1 through 9 the illustrated cutter assemblies typical of this invention consist of a shaft 10 on which is mounted a hub 12 shaft 10 and hub 12 are fixedly secured to the face of a rotatable cutterhead not shown of a tunnel boring or raise boring machine in a manner known in the art seal carrier 14 is located between shaft 10 and hub 12 and supports bearing seal ring 16 bearings 18 are typically tapered roller bearings and the bearing chamber typically is lubricated and sealed by bearing seal rings 16 in a known manner inner bearing races 20 support bearings 18 on shaft 10 and outer bearing races 22 support hub 12 on bearings 18 such that outer bearing races 22 and hub 12 roll on bearings 18 bearing cages 24 retain bearings during relative rotation of hub 12 about axis 25 hub 12 is circumferentially disposed over shaft 10 such that the rotation of hub 12 on bearings 18 relative to shaft 10 is in a manner conventional per se hub 12 being substantially wheel shaped has a peripheral surface 26 of a given width shoulder 28 of hub 12 is located on one side and.