cutting face 90 of cutter 74 is properly oriented for cutting along the path indicated by arrow 94 cutting face 90 is generally oriented perpendicular to the direction of travel of the cutter 74 in this operating mode which is parallel to dashed line 98 passing through about the drilling center of rotation 30 in a similar manner when the drillout bi center drill bit 10 is rotating about the passthrough center of rotation 34 cutting face 92 of cutter 74 is properly oriented for cutting along the path indicated by arrow 96 cutting face 92 is generally oriented perpendicular to the direction of travel of the cutter 74 in this operating mode which is parallel to dashed line 100 passing through about the passthrough center of rotation 34 in order to survive severe abrasive drilling conditions the cutting face 90 of cutter 74 is quite different from that of cutter 72 a pdc cutting element 102 is mounted on cutting face 90 a small distance 104 from the end 106 of cutter 74 exposed at the drilling face 17 of the drillout bi center drill bit 10 during the drillout phase a small amount of wear will occur on end 106 after drillout the bit will then start drilling a full diameter hole in the earth however in abrasive drilling conditions even cutters near the center will wear rapidly therefore the end 106 of cutter 74 will wear rapidly exposing the pdc element 102 once this happens the cutter.