Abstract: The device for forming a variable-shape mold surface includes a plurality of cylindrical and helically threaded rods each having a mold surface defining end. These rods are assembled into a bundle of laterally adjacent rods in which (a) the helical thread of each rod is engaged with the helical threads of the adjacent rods, (b) each rod is rotatable about its longitudinal axis, and (c) the mold surface defining ends of the rods define the variable-shape mold surface. Upon rotation, the thread of one helically threaded rod slides on the threads of the adjacent rods to impart longitudinal movement to this rod relative to the adjacent rods and therefore axial movement of the mold surface defining end of this rod, to thereby modify the configuration of the variable-shape mold surface. Each rod has a second end shaped for engagement thereof with a digitally controlled rod rotating tool.