Occasionally I have to scale a shape beyond the usefulness of the original master rocker template. At this point a new scaled master rocker is needed for a different blank size. To maintain the integrity of the shape the rocker is isolated from the program and a new master rocker is created from the scaled file and cut on the CNC with the exact rocker of the new scaled version.
There are many different methods of measuring and making rockers templates. Most outside of the shaping arena (and a lot of shapers) have a difficult understanding how critical it is to maintaining and utilizing master rocker templates for maintaining accuracy and consistency. I feel it is one of the most critical aspects of the designing and shaping process.
Most shapers rely on the blank manufactures to deliver the blanks with the correct rockers. Most don’t bother to check before they start the shaping process. I just recently had a shaper show up at my door with a blank with the incorrect rockers and wanted me to shape the blank. I could tell immediately the blank was off and it would be impossible to shape his “model”. This after he just sent me two blanks previously from another shaper that was marked as the same two rockers that should have been identical but both were completely different from each other and the master shape. Much to his chagrin, he didn’t appreciate it when I asked him if he bothered to double check his rockers.
Contrary to many shapers I am mainly a "deck rocker" centric shaper. I prefer to design and shape the deck rocker as the foundation to my shaping methods and the process begins with an accurate deck rocker. All of my designs originate from hand shapes that are digitized by 3D scans. I do not use any of the surfboard rendering software.