Techniques and technologies for large-scale additive manufacturing

The work presented in thesis aims to address gaps in knowledge surrounding Large- Scale Additive Manufacturing technology, specifically for Fused Deposition Modelling. Chapter 2 introduces material extrusion Additive Manufacturing, outlining some of the important aspects of the technology as well as terminology specific to the technology used throughout the rest of the thesis. Chapter 3 presents a workflow solution to achieve out-of-plane printing. These outof- plane toolpaths are demonstrated in Chapter 4 as a novel approach for creating a true non-planar FDM printed parts. Chapter 5 presents work undertaken to develop an in-process, autonomous system consisting of a thermal camera and software to monitor a print during manufacture and modify key process parameters to ensure successful printing and reduce waste from failed parts. The chapter covers the initial development work, the building of heuristic understanding and initial implementation (e.g. detecting print defaults), leading to rectifying print defects on-the-fly. Chapter 6 presents work leveraging learning from the thermal monitoring system in Chapter 5 as well as establishing the relationship between thermal properties during manufacture and resultant mechanical properties. The work investigates the effects of printing multiple components in a single print job and the importance of toolpath planning, particularly for large-scale components where fit and form must be correctly balanced with mechanical properties. Finally, Chapter 7 discusses an application of LSAM for bridge manufacturing, specifically work conducted during the COVID-19 pandemic producing PPE using LSAM as a bridge manufacturing method to between desktop-scale AM and injection moulding. Overall, this thesis assembles together significant work that not only builds a deeper understanding of LSAM technology and the parts it produces but in addition offers new insights into the ways in which the technology can be used, developed and improved to overcome challenges to its widescale adoption across more industry sectors