“The Hangprinter is one of the most unusual 3D printer concepts yet seen, and it actually works. The Hangprinter is a project by Torbjørn Ludvigsen, based in the city of Umeå in the northern end of Sweden. Ludvigsen, who goes by the handle “Tobben”. It’s a RepRap variant designed by Ludvigsen apparently in 2014, but is now something a lot more than just an idea. The Hangprinter’s name isn’t just for fun: this machine indeed has no frame at all, unless you count floors, walls and ceilings as such. It operates by simply hanging by cables from the ceiling and three anchor points on the floor. The central extrusion device is stabilizing in space by tight, controllable cable lengths on the three floor attachment points, as well as gravity pulling down along the z-axis hanger strings. The extrusion unit can raise itself by pulling on the z-axis cable, and move laterally by appropriate manipulations of the three floor anchor cables. The installation of the anchor points is more or less arbitrary, and apparently you simply set their locations in firmware so that the system can compute the movements accurately. “