DELTA 3D PRINTER v1.2 most of popular, optimized geometry. Download step or stl and build your own printer, buy electronics components and thats it. Yes its useful to have 3d printer nowadays, you can print toys, print repair parts for everything around you, case for iphone or smartphone, vase, cup, glases, studs and etc.
Messege me if you`re looking for drawings or detail parts for plasmacutting machine to build some parts from sheet metal, I can give it for free.