The most widely used 3D printing software is Autodesk Fusion. It Is a great tool aimed at professionals for designing and manufacturing products. Inexperienced designers can start out with Tinkercad (another software from Autodesk) before transitioning to Fusion.

You have to 3D print each part of the 3D printer individually, and then assemble them yourself. Also, there are still a few parts of a 3D printer that can't be 3D printed as electronic components. So you can 3D print a 3D printer, but not totally for now. This also stands for plastic 3D printing only.

The process consists in sorting and cleaning plastic pieces taken from defective household appliances, grinding them to small granules, and feed those granules to a home made small extrusion line. After a quick post-processing step, the output filament can be used by a 3D printer to print new objects.