18 a 18 b 18 b shown include a conical internal surface 40 this surface mates with a protrusion on the plastic material 11 such that the cutting die is properly aligned to make a cut in an exact location during the operation of the cutting cycle the plastic material 11 is moved on the striker plate under the cutting die 10 the cutting die 10 is then lowered onto the sheet to perform the cut as the die is lowered the conical protrusion on the sheet aligns with the conical internal wall 40 as described the die board 20 is loosely connected to the buildup plates therefore the die board 10 can easily move into alignment with the protrusion on the plastic material 11 by aligning with the internal conical wall 40 of the stopper 18 b in an alternative embodiment the alignment can take place by having the die board securely mounted to the buildup plates while the plastic material 11 is moved into alignment with the die board in the present embodiment the stopper 18 b extends from the buildup plate 24 to a point just below the top of the cutting blade 12 the bottom of the die board 20 includes a chamfer which allows the bottom of the stopper 18 b to sit flush on the buildup plate 24 the stopper is prevented from dislodging from the die board 20 by a retaining ring 42 the retaining ring is larger in diameter than the bore in the die board 24 that houses the stopper 18 b thus preventing the stopper from dislodging the stopper 18 b contacts the buildup plate at a.