US Patent 10513076 3D printing devices and methods

3D printers include a feed stepper motor coupled to an extruder, a platen positioned adjacent the extruder, a platen support coupled to a platen lifter, and directional stepper motors, wherein the extruder comprises an air scoop, extruder nozzle and heater, wherein the heater is positioned to heat the extruder nozzle and air to provide heated air and the air scoop is configured and positioned to route the heated air which is emitted adjacent the extruder nozzle directly onto the surface of a workpiece positioned on the platen. A feed stepper motor may include a hollow bore motor shaft. A substrate made of the same material being extruded may be provided. A method of 3D printing employs such a substrate.