Toolpath Static Analysis Testing for Additive Manufacturing

Abstract

Fused Deposition Modelling (FDM) 3D printers are the most common 3D printers in the world. However, most of the world’s 3D printers have little-to-no security to prevent cyber-attacks. Most small businesses that employ 3D printing technology do so with minimal security. A possible approach to assuring 3D product and printer quality is static analysis testing. In reverse engineering, static analysis observes a file’s inner workings before execution to determine if malicious elements are present. This thesis investigates and proposes how static analysis testing can be applied to Additive Manufacturing (AM). This process executes a series of test cases on values derived from the toolpath file before the physical printing process takes place to ensure that the data will not negatively affect the printer. With this approach, defects can be detected at the 3D model, stereolithography (STL), and toolpath levels of the 3D printing process on G-code based and non-G-code based toolpath files. This research effort demonstrates test cases that can prevent attacks on five printing attributes (including extruder temperature, heat bed temperature, infill, layer thickness, and fan speed). An attack on one or more of these attributes can cause the part’s mechanical properties to change or damage the printer itself. These test cases determine appropriate slicer settings, and commands are within the printer’s capabilities. This study demonstrates that a toolpath testing driven approach can effectively defend against cyber-physical attacks on 3D printers and the 3D printing process.