Affine transformation-based path generation method for supportless rotary 3D printing

Purpose Rotary 3D printing has emerged as a promising alternative to conventional planar-based 3D printing, it offers solutions to inherent limitations, such as the need for support structures in overhanging geometries. Traditional approaches necessitate complex cylindrical slicing and curved path planning processes, which not only impose high computational demands but also lack compatible with existing planar-based 3D printing algorithms and software. To address this limitation, the purpose of this study is to develop innovative approaches for rotary 3D printing that streamline path generation and improve compatibility, thereby enabling the full utilization of the extensive resources of planar-based 3D printing algorithms and software. Design/methodology/approach First, a mesh model affine transformation method is proposed to adapt the geometric shape according to the mechanical structure of a rotary 3D printer. This enhances the maximum self-supporting angle of the original model. Subsequently, conventional planar-based 3D printing software can then be performed directly on the affine-transformed model. Finally, an automated inverse transformation procedure is conducted on the rotary 3D printing system configured with Cartesian kinematics. The generated planar paths – incorporating material compensation – can accurately fabricate the original models. Findings Experimental results demonstrate that the proposed affine transformation-based path generation method can effectively mitigate or eliminate the need for mandatory support structures typically required in conventional planar 3D printing, while demonstrating improved performance in both printing efficiency and material utilization compared to planar 3D printing techniques. Practical implications The proposed affine transformation-based method generates support-free planar paths for rotary 3D printing. It establishes a simplified data processing pipeline and maintains compatibility with existing tools, thereby enhancing both practicality and scalability. Originality/value The proposed affine transformation-based method opens new avenues for applying existing planar-based printing algorithms and software to rotary 3D printing. It serves as a powerful supplement to current data processing technologies in this field.