B.C. That's because numbers are the language used by drafter designers, and everyone they work with, from engineers, machinists and suppliers. For instance, every part in a motor has to be designed and built. And every part in that motor has to fit with and work with all the other parts. Everyone has a different idea about how big an apple is. So, that's why numbers are used.
Numbers are precise and mean the same thing to everyone.
Once a mechanical drafter designer has calculated the numbers, the numbers must be interpreted. Once that judgement is made, the design and drafting process can continue. Mechanical drafter designers use computers to help them do many of their calculations. For instance, Gilbert uses the CAD system to check stress and strain, to calculate distances, and conduct other types of analyses. Still, it's very important for Gilbert to understand how the calculations were done and to work them out himself.