Knife attachment for a sheet cutting system

A knife attachment for a sheet cutting system having a frame that supports a work piece, said knife attachment comprising:

• a base having a top surface and a bottom surface, said base having a hole extending therethrough between said top and bottom surfaces;
• an elongated blade holder having a length dimension and having a distal end, said blade holder extending through said hole and being disposed in a plane that is substantially perpendicular to said base, said blade holder having a first slot extending therethrough and extending along said length dimension of said blade holder;
• a mounting plate mounted on said top surface;
• sliding means situated in said first slot to allow said blade holder to slide along said length dimension, said sliding means being mounted on said mounting plate in a manner to define a depth penetration path along said length dimension of said blade holder, said sliding means including a post and an adjusting member, and wherein said adjusting member and said mounting plate cooperate to lock said blade holder to said mounting plate to define a desired penetration depth;
• and
• wherein said mounting plate includes a second slot having a length and extending therethrough, said adjusting member being slidably positioned in said second slot and adjustable to lock said blade holder to said mounting plate to define (a) said desired penetration depth and (b) a desired angle in a plane substantially perpendicular to said base, said angle being within a range defined by said length of said second slot.