Together with the ZHAW Institute of Applied Mathematics and Physics, the researchers were able to develop a special print-data preparation method so as to be able to print using their new process at all. “It is not based on parallel layers to the print bed, as is usually the case, but rather on cone-shaped ones,” explains ZHAW researcher Michael Wüthrich. The researchers have designed two new algorithms to this end. A first algorithm transforms the geometric data so that the operating commands for the printer can be generated using conventional software. A second algorithm then has to transform these operating commands back again so that the part is finally printed on the RotBot according to the initial geometry. “The time-consuming part of the data preparation is thus still handled using commercially available software and the geometries can be printed fully automatically,” says Wüthrich.

A 3D printer which was able to print overhangs without support material thanks to its six axes and moveable printing plate had already been presented by the ZHAW School of Engineering as far back as four years ago. The creation of the print data was, however, time-consuming as it required coordination between the printhead, the printing plate and the printed part. In contrast to the prototype presented at that time, the technology used in the RotBot is simpler. “RotBot can be built relatively easily on the basis of a conventional printer with Cartesian kinematics,” says Wilfried J. Elspass. The ZHAW researchers in Winterthur say that certain manufacturers could soon be offering their solution as an upgrade kit for their 3D printers.