3D Printing of Nonplanar Layers for Smooth Surface Generation

Additive manufacturing processes are inherently subject to discretization effects. For most technologies, stair-stepping artifacts impair the surface quality of 3D printed objects, especially when the surface slope is close to horizontal. In this paper we propose a novel Fused Deposition Modeling (FDM) slicing approach that combines nonplanar and planar layers, increasing printing quality and resulting in smoother, stronger object surfaces. Our slicing algorithm automatically detects which parts of the object should be printed with nonplanar layers and uses a geometric model of the printhead and extruder to generate collision-free toolpaths. Our open source implementation is based on the popular Slic3r tool and can be used on all common three-axis 3D printers. We present typical printing results and compare surface quality as well as slicing and printing times with traditional and adaptive planar slicing.