Patent ID: 8641337

Claim:
A method of forming at least one part of a selected profile from a workpiece mountable on a porous spoil board disposed on the worktable of a CNC router machine having means for applying a negative pressure on the underside of said workpiece mounted on said spoil board, providing a pressure differential across said mounted workpiece, and a cutting tool displaceable along x, y and z axes to form said selected profile, comprising: programming the controller of said machine to generate a cutting pattern to provide said part profile, compute the area of said part, map the cut path of said part, compote and store the value of said cut path area, compare the computed area value of said part with a predetermined area value and position said cutting tool along the z-axis to provide less than a through cut of said workpiece where said computed area value is less than said predetermined area value and provide a through cut where said computed area value exceeds said predetermined area value; mounting said workpiece on said worktable; actuating said negative pressure applying means; and operating said machine to execute said program.