A fully automatic non-planar slicing algorithm for the additive manufacturing of complex geometries
Gabriele Maria Fortunato, Matteo Nicoletta, Elisa Batoni, Giovanni Vozzi, Carmelo De Maria
Abstract
The aim of this work is the implementation of a novel non-planar slicing algorithm, capable of combining traditional planar layers with non-planar ones. The geometry to be reconstructed will consist of an inner volume made of planar layers, and an outer shell made of non-planar layers. Both planar and non-planar layers are in turn constituted by an outer region, the shell, and an inner region, the infill. The outer non-planar shell guarantees an enhancement in the aesthetic properties and electro-mechanical behaviour of the printed objects, as well as a better adhesion when directly built onto a complex geometry. The algorithm was tested on three different three-dimensional models usable for aerospace, electronics, and biomedical applications showing robust results. An experimental validation was carried out by using a 5-axis robotic printer equipped with an extrusion-based printing unit. Different structures combining planar and non-planar paths were printed onto complex substrates, as well as into a bone defect that was completely regenerated following the proposed approach. The comparison between our method and the existing non-planar slicing methods revealed several advantages such as the capacity to generate both top and bottom non-planar surfaces, the possibility to manage complex concave/undercut structures, as well as the option to directly register the planned printing path on the receiving substrate in the working environment. To ensure proper and easy use, a graphical user interface was also created.