Section: New Results

Anti-aliasing for fused filament deposition

• Participants: Hai-Chuan Song, Nicolas Ray, Dmitry Sokolov, Sylvain Lefebvre

Layered manufacturing inherently suffers from staircase defects along surfaces that are gently sloped with respect to the build direction. Reducing the slice thickness improves the situation but never resolves it completely as flat layers remain a poor approximation of the true surface in these regions. In addition, reducing the slice thickness largely increases the print time. In this project we focus on a simple yet effective technique to improve the print accuracy for layered manufacturing by filament deposition. Our method [16] works with standard three-axis 3D filament printers (e.g. the typical, widely available 3D printers), using standard extrusion nozzles. It better reproduces the geometry of sloped surfaces without increasing the print time. Our key idea is to perform a local anti-aliasing, working at a sub-layer accuracy to produce slightly curved deposition paths and reduce approximation errors. We show that the necessary deviation in height compared to standard slicing is bounded by half the layer thickness. Therefore, the height changes remain small and plastic deposition remains reliable. We further split and order paths to minimize defects due to the extruder nozzle shape, avoiding any change in the existing hardware. We apply and analyze our approach on 3D printed examples, showing that our technique greatly improves surface accuracy and silhouette quality while keeping the print time nearly identical.

Figure 6. Printing a wedge model clearly reveals the staircase defects that plague 3D printing. (a) Input 3D model; the bottom edge length is 20mm and the angle of the incline plane is 10. (b) Global view and (c) side view of a standard, flat layer printed result. (d) Global view and (e) side view of our anti-aliased printed result, revealing the improvement in surface accuracy and silhouette smoothness