Optimised 3D Printed Structures (2019)

Optimised 3D Printed Structures (2019)

Hamish Morgan

Developing a six-axis robotic spatial printing system

Hamish Morgan saw the opportunity to combine two innovative technologies, freeform printing and topological optimisation, to produce a complete spatial printing system. The system he developed during his master’s thesis is capable of progressing from form design and optimisation through to object production.

Freeform printing is an advanced form of additive manufacturing where material is extruded directly into a 3D structure, unlike traditional layer-based printing. This method offers enhanced control over material placement, leading to lightweight lattice structures. Topological optimization, on the other hand, is a method of computationally generating forms from input data, to withstand real world forces while minimising material usage. The integration of these two technologies led to the development of a novel computational system for translating optimised forms into spatially printed structures.

Hamish employs a design science methodology, incorporating literature review, software evaluation, and experimental calibration of a six-axis robotic spatial printing system. The main stages include identifying opportunities for development through literature and precedents, performing extrusion experiments to determine optimal print settings, and the iterative development of multiple computational systems. One system is selected for continuous improvement, culminating in an application-based experiment to create an optimized chair design. The thesis evaluates different structural analysis and CAD/CAM software, ultimately selecting Millipede for its versatility in performing a wide range of analyses and optimizations. Rhinoceros 3D and Grasshopper are chosen for their seamless integration with Millipede and robust support networks. The hardware setup includes an ABB six-axis robotic arm and a custom-built extruder, optimized for PLA plastic due to its superior strength, low shrinkage, and biodegradability.