Also referred to as: 3d printing, Fused Deposition Modeling (FDM), Fused Filament Fabrication (FFF), Stereo Lithography (SLA) and a slew of others that are developing technologies for hobbyists.
I personally have found this to be a waste of resources. Every time I have a part I would like to make, I can run out into the shop and make it on the lathe or mill faster than the time it takes to print. As an added benefit, the parts made on traditional machine tools are actually useful i.e they fit and don’t break as easily. Threads turn out particularly useless on the printer. Special thread shapes and allowances must be used in the design in order for them to print to fit.