How do I output a shortened crease slot in a dieboard for a design that will be produced with a steel counter?
A user can "shorten" a crease in a design when a steel counter is to be used for production. There are two values to consider: the Crease Channel End and the Crease Cutback.
The Crease Channel End is the amount the crease channel is offset from the panel edge. This ensures that the knife that cuts the perpendicular panels edge has a place to land and does not encroach into the crease channel.
The Crease Cutback is an additional value that the crease is shortened which allows a buffer to prevent cropping or cutting of the material as it compresses into the channel.
Using the above values, a crease channel would be created as follows:
The corresponding crease rule and its resulting slot can be modified according to the Different top and bridge setting used to create the steel counter. Internally, the the crease is still its original length. However the effective crease has been "shortened" by 0.16 (0.08 * 2 for each end ) to accommodate the channel ends and crease cutbacks.
Crease Rule Options
The user can decide to use creasing rule of the original length and have the top part of the rule cut back to match the total shortened crease. Use a Crease cutback bridge (B) of 0, that is no physical shortening of the rule.
The user can decide to shorten the crease rule so that it does not meet the perpendicular cut. This can be done when the dieboard base plate is rigid and strong enough to accommodate such rule. In this case, the total shortening of the rule and the top are the same. Use a Crease cutback bridge (B) equal to the total crease shortening.
The user can decide to shorten the crease rule so that it does not meet the perpendicular cut and the top is cutback. Use a Crease cutback bridge (B) equal to the crease channel end.
When the crease rule is physically shortened, that is, Crease cutback bridge > 0, ArtiosCAD keeps the original crease length intact and defines bridges on either end of the crease rule path.
Here is some DDES3 output. The red entry is the crease definition. The original length is 10. Note there are four custom bridges. The green entries are the end bridges which effectively shorten the rule. Note the length is 0.041 which is the Crease cutback value (B).
LINE MAIN 0 0 10 0 101 0 P2 2 0.1875 LINE MAIN 10 0 10 15 101 0 P2 3 0.1875 LINE MAIN 10 15 0 15 101 0 P2 2 0.1875 LINE MAIN 0 15 0 0 101 0 P2 3 0.1875 LINE MAIN 0 7.5 10 7.5 102 0 P2 -4 BRIDGE C 0.00205 0.041 BRIDGE C 0.25000 0.1875 BRIDGE C 0.75000 0.1875 BRIDGE C 0.99795 0.041
Here is a dieboard output. The area in green is the front bridge on the crease rule.
If the top part of the rule and the rule bridge are to differ, then the diemaker is responsible for cutting back the top part of the rule. ArtiosCAD does not allow nicks to be added to creases.