Toolpath Overhang Optimization for the Large-Format 3D Printing of Bespoke Shapes

Abstract

This paper presents a closed curve trimming algorithm for overhang optimization in large-format support-free 3D printing of bespoke manifold shapes. Large-format 3D printing enables efficient fabrication of complex, bespoke shapes. Because of the material properties and surface quality requirements, such shapes are typically printed without support structures and have to be designed as support-free. Most current methods of overhang optimization are limited to certain types of geometry and do not apply to bespoke shapes. Our method directly optimizes sliced toolpath curves with minimal geometric modification. Given an overhang limit, it ensures that all resulting toolpath curves are strictly within the overhang limit while preserving their orientation and preventing intersections. The algorithm is based on curve offsetting and trimming, and is applicable to closed toolpath curves that represent the boundaries of a solid volume.