A 3D printer connects to a computer and, using stepper motors to move a print head that extrudes resin or plastic, 'prints' a three-dimensional object that is modelled on the computer.
3D printers make it possible to manufacture specialty parts in order to build and repair complex machinery at a local level.
Although 3D printers generally use commercial printer filament, there are some 3D printers that directly recycle and use plastic waste.