Level-by-level 3D printing of multi-level structures using removable cable-support masts and a cable-guided nozzle

A method of building a multi-level structure at least partly by way of three-dimensional (3D) printing using a cable-guided nozzle, said method comprising gradually constructing said multi-level structure level-by-level in a plurality of stages, during which at least one stage comprises building an additional level of said structure atop one or more previously built levels of said structure by:

• (a) installing cable support masts in a manner supported on the one or more previously built levels of said structure, and in positions where cable-emergence points of the cable support masts reside outwardly of a two-dimensional footprint to be occupied by the additional level, wherein each one of the cable support masts is accompanied by a respective motorized cable winder having a respective positioning cable wound thereon by which said positioning cable is windable and unwindable to shorten and lengthen a reach of said respective positioning cable from the cable-emergence point of said one of the support masts, from which the respective positioning cable runs to the nozzle and is connected thereto for both cable-suspended support thereof and cable-controlled movement thereof via operation of said respective motorized cable winder;
• and
• (b) with said cable-guided nozzle both suspended by the respective positioning cables of the cable support masts and movingly controllable by operation of the respective motorized cable winders of the cable support masts, 3D printing at least part of said current level of the structure onto said one or more previously built levels using said cable-guided nozzle during cable-controlled movement thereof performed by operation of the respective motorized cable winders to reposition the cable-guided nozzle via said respective positioning cables.