MANUEL JIMÉNEZ GARCÍA AND GILLES RETSIN
DISCRETE METHODS
Introduction
be serialised, meaning that different line fragments can be tested in all rotation possibilities prior to commencing the printing of the full object. When the prototyping phase is complete, the object can be printed with certainty that further errors will not appear in the process since it is made out of previously tested elements. Discrete Design v1.0 and v2.0 generate complex non-repetitive structures from the aggregation of linear elements. Instead of working with the whole object, the software enables designers to work with pieces that can later be brought together. It introduces structural optimisation as an intermediate step between design and toolpath generation, allowing users to test the ‘printability’ of 3D toolpath fragments aggregated into any given mass. Each element is then tested in all possible directions so that they can anticipate errors that may show up in print. According to co-author Gilles Retsin:
To date, research into robotic large-scale 3D printing in architecture and other industries has been one sided. Architects tend to stress the implications of digital design technologies in the production of novel architectural forms without seriously addressing the technical side of their fabrication process. As a result, digital processes are slower than traditional manufacturing methods, while the excessive complexity of architectural forms and their constitutive parts renders their eventual assembly on site inefficient. In contrast, engineers from construction and other industries have exclusively focused on the fabrication process. Although this has led to significant innovations in the development of robotic machines and materials, it has not sufficiently affected the architectural design process and its knowledge base. If 3D-printed buildings are to exist in the future, the approach and software must be rethought. This research pursues a broader holistic framework that considers these two separately developed research strands as intertwined and proposes a computational design method for large-scale 3D printing that focuses on the organisation of toolpaths for the continuous addition or layering of material.
It’s very interesting not only for architects and designers, but specifically for engineers in automobile and aerospace … . This basically allows them to really optimise and tailor large 3D-printed structures and therefore save lots of material … . This is a game changer and the first software that allows you to directly design and organise millions of toolpaths for 3D printing (Retsin 2017).
Software Development
Discrete design involves the use of a limited number of different pieces that make a whole using a limited number of connection possibilities. Applied to 3D printing, this method implies the use of a family of fragments that connect together to generate a continuous line of material to be extruded using a robot (4). This allows errors to
4 PLA robotic-extrusion process at Nagami Design in Avila, Spain. The image sequence features an ABB 4600 robot equipped with the first version of Nagami’s pellet extruder, developed primarily for VoxelChair v1.0.
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