You might even want to start with a list of simple machining operations, much the way you’d approach creating a part “off the cuff” and without drawings on a manual machine tool.
You may also need to start from images, vector art from a drawing program, or perhaps some other file types. Most of the time this is a function of a CAD program, but not always. When you’re starting out with CNC or 3D Printing, the first thing you’ll want to get your arms around is creating some sort of model, drawing, or representation of your part.
