Hello all,

beginning with learning to create 3D printable models, I am at the very start and therefore I would like to ask you a few more questions if I may. Let's say, I want to recreate a knob of a device, that I do not have at hand, but just see from pictures. How do all the pros on different forums and libraries, recreate the buttons in a CAD model? is there any source where one can get the exact dimensions being used? Or is there any other way, how to recreate that? I just want to start with a simple example like a knob, but what would be a proper way to re-engineer this?