Some 42 years ago, I did the CNC programming for a telephone mold. This was done by transforming the blueprints into a 3D wireframe which was then used to create a 3D surface model. The surface geometry was then used to generate the toolpaths needed to cut the core and cavity of the mold using a 3-axis CNC mill. Graphite electrodes were also cut to burn details with an EDM machine. This was all programmed using a Calma CAD/CAM system.
Today, I was watching a movie (“Chaos”) when I saw “my” phone and the details of that project came flooding back into my head.