The print bed is a mirror, on top of the aluminium plate, headed by a large silicone heat pad. The extruder is the new E3D Hemera with a 0.8 mm nozzle. To move all the weight, all 3 axes are driven by double NEMA17 steppers, via a DUET3D board with an expansion board for the extra motors. The frame of the new machine is built using 20×20 and 20×40 aluminium V-slot extrusions with some square tubing for reinforcement. needed a big printer for his big projects (videos below), so he built his own i3 style printer with a 800 mm × 500 mm usable print bed and about 500 mm vertical print height. Established FDM 3D printers designs generally lead themselves well to being scaled up, as long as you keep frame stiffness, alignment and movement in mind.