Discrete Methods for Robotic Spatial Extrusion by Manuel Jiménez García and Gilles Retsin

Bartlett Design Research Folios

Manuel Jiménez García Gilles Retsin Discrete Methods for Robotic Spatial Extrusion

BARTLETT DESIGN RESEARCH FOLIOS

Manuel Jiménez García Gilles Retsin Discrete Methods for Robotic Spatial Extrusion

MANUEL JIMÉNEZ GARCÍA AND GILLES RETSIN

DISCRETE METHODS

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CONTENTS

1 (previous) Front view of VoxelChair v1.0. Designed using the Discrete Design v1.0 software and printed at Nagami Design for the exhibition Imprimir le monde, Centre Pompidou, Paris, 2017.

2 The Ogonori chaise longue, designed using Discrete Design v2.0 software and 3D printed using Nagami’s robotic plastic-extrusion technology. Off-the-shelf circular aluminium profiles were used for the legs.

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Project Details

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Statement about the Research Content and Process

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Introduction

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Aims and Objectives

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Questions

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Context

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Methodology

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Dissemination

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Project Highlights

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Bibliography

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Related Publications

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Project Details Author

Manuel Jiménez GarcÍa

Co-author

Gilles Retsin

Title

Discrete Methods for Robotic Spatial Extrusion

Output Type

Software design and built prototypes

Dates

2014 to 2020

Developed Software

Discrete Design v1.0 and v2.0

Prototypes

VoxelChair v1.0 and the Ogonori chaise longue

Material

Biodegradable Extruded Polylactic Acid (PLA)

Robotic Fabrication

Miguel Angel Jiménez GarcÍa, Ignacio Viguera Ochoa

Rationalisation

Ivo W. Tedbury

Consultants

Design Computation Lab

Fabrication

Nagami Design, Vicente Soler

Clients/Commissioning Bodies

ACADIA, Autodesk, Centre Pompidou

Acquisitions Centre Pompidou, Paris (2017), Philadelphia Museum of Art (2019) Funding

£21,600

Funders 2016 Autodesk ACADIA Emerging Research Award, Centre Pompidou, Philadelphia Design Museum

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PROJECT DETAILS

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3 VoxelChair v1.0.

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Statement about the Research Content and Process Description

Methodology

Discrete Design v1.0 and v2.0 is discrete aggregation software developed specifically for large-scale 3D printing. The software aggregates thousands of instantiated fragments into a continuous line. Two fullscale prototypes – VoxelChair v1.0 and the Ogonori chaise longue – were created to test the software and its various iterations.

1. Iterative coding and scriptwriting for new software development;

Questions

4. Reviews, lectures and seminars to ensure continuous peer feedback and knowledge exchange.

2. Iterative digital prototyping of line fragments; 3. Iterative physical testing using robotically 3D-printed prototypes to serialise and anticipate errors;

1. How can robotic 3D printing scale-up to produce architectural structures?

2. How can the 3D-printing process be accelerated and efficiently optimised to reduce the amount of material used?

How can possible errors be anticipated?

Dissemination

Discrete Design v1.0 and v2.0 and the 3D-printed prototypes have featured in four exhibitions and seven invited talks, lectures and conference presentations internationally.

The authors have written about the project in seven chapters and have published two related edited volumes, one for Detail and one for Architectural Design. VoxelChair v1.0 has been positively reviewed in print (Wired) and on numerous online platforms like 3D Printing.

3. How can a design method accommodate local variations of material density in the prefabrication of 3D-printed objects, while also ensure their structural stability?

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STATEMENT ABOUT THE RESEARCH CONTENT AND PROCESS

Project Highlights

VoxelChair v1.0 is now part of the permanent collection of the Centre Pompidou, Paris, and the Philadelphia Museum of Art. Ogonori won a ‘Special Mention’ in the 2018 3D Pioneers Challenge exhibition in Erfurt. Further to this, the authors won the ACADIA Autodesk Emerging Research Award in 2016 for their paper ‘Discrete Computational Methods for Robotic Additive Manufacturing: Combinatorial Toolpaths’.

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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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INTRODUCTION

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Prototypes

GarcÍa and Retsin made two 3D-printed prototypes in the development of the software, to test its possibilities and limitations and explore different principles in the digital design workflow. VoxelChair v1.0 (1) and the Ogonori chaise longue (2) are considered to be intermediate prototypes in scaling-up to structurally sound buildings.

VoxelChair v1.0 was developed using the first Beta version of the Discrete Design software, written in Java and using functionality from Processing 3.0 by Casey Reas and Ben Fry. The software analyses a given volume, in this case the Vitra Panton Chair (1967), and distributes two types of line fragments with different densities that respond to the structural requirements throughout the object (5).

The Ogonori chaise longue is a demonstration of the extended capability of Discrete Design v2.0, which was completely rewritten in C#. This version includes the possibility to adapt the boundary line fragments to the original surface, avoiding a stepped voxel morphology, in this case for a chaise longue. Another key functionality is the printability checker, this means that any created geometry can be simulated as if it would be robotically extruded. Fabricators can add the constraints of the biodegradable plastic extruder nozzle – Nagami’s extruder was simulated for Ogonori – and check for any printing problems before exporting the geometry to be 3D printed.

5 Visualisation of 24 variations of VoxelChair v1.0, developed following different structural conditions within the volume of a Vitra Panton Chair, 1967.

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INTRODUCTION

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Aims and Objectives

Questions

The long-term intention of this research project is to integrate computational design and fabrication process, and to develop software and a digital design strategy for large-scale 3D printing in architecture.

The Discrete Design software is specifically concerned with scale, structural stability and efficiency. The main objectives include accelerating the 3D-printing process, reducing material used and anticipating possible errors in the final print, thereby facilitating the transition from small object to large-scale architecture. More broadly, the research aims to establish a universal approach for discrete design methods.

1. How can robotic 3D printing scale-up to produce architectural structures?

3D printing has demonstrated its small-scale efficiency, and is the ultimate distributed manufacturing tool for objects that can be made using desktop 3D printers, such as Ultimaker, Makerbot or Formlabs Form 2.

Robotic 3D printing offers a considerable shift in scale, allowing for the creation of larger products, such as furniture, with commercial accessibility, e.g. Nagami or Dirk Van der Kooij. These examples help to envision the next jump in scale: to architecture. This requires rethinking our tools to adapt to the technology in a robust manner, thus creating design and computational methods specific to largescale robotic 3D printing.

2. How can the 3D-printing process be accelerated and efficiently optimised to reduce the amount of material used?

How can possible errors be anticipated?

When 3D printing at large scale, constraints are much more prominent and show the necessity of a design method that considers them from early on. One possible approach, followed in this project, is to adopt a discrete design method. This allows errors to be serialised, meaning that if we can prototype a line fragment in all possible directions, and we create the entire structure based on a repetition of that fragment, we can ensure that every part of the object will be printable without unexpected problems.

This is especially important in large-scale 3D printing, as the manufacture of larger volumes is more time consuming.

6-8 (previous) VoxelChair v1.0, details showing the mass discrete gradient generated by the combination of flat and 3D line fragments, leading to a gradual change in material and structural organisation from porous to dense.

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AIMS AND OBJECTIVES / QUESTIONS

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9–10 Discrete Design v2.0 screenshots showing the material extrusion simulation. This feature allows any possible errors or collisions to be detected before printing.

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3. How can a design method accommodate local variations of material density in the prefabrication of 3D-printed objects, while also ensuring their structural stability?

By conceiving the object as a volume rather than a composition of surfaces, we can assign different properties to each particle, including porosity, aspect and strength.

When working at large scale, the use of voxels as elemental particles seems appropriate as they can vary in size according to the desired resolution (in most cases, rather low in comparison with small-scale objects). The Discrete Design software allows for a finite element analysis to be performed for a given object, linking voxels of different mass and density in response to the clarification of stress values (11). Thus, more porous voxels – in this case lighter line fragments – will be located in those areas with low-stress values, whereas denser line fragments will substitute voxels in areas under higher stress (12). This produces not only a volumetric structural differentiation but also a high degree of heterogeneity within the object.

11 Diagram depicting the distribution of line fragments in relation to structural requirements for VoxelChair v1.0. Air-printed cells (3D types) are used in areas with lower stress values, corresponding to the basic voxelization.

A combination of 2D and 3D types are used in intermediate areas (Division 01), while 2D types fill those under higher stress (Division 02).

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QUESTIONS

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12 Diagram depicting the front, side and top of the VoxelChair. The gradient of stress levels is shown within the object.

13 Octree subdivision of the voxelised space, depicting levels from left to right, to be used as guidance for the use of different line fragments throughout the volume.

14 (overleaf) Image of the Ogonori chaise longue taken with a backlight to show the levels of transparency in relation to the differentiated density of the line fragments.

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Context

volumes. Assembling the mass-customised parts also proves comparatively inefficient compared to the assembly of identical elements, since they require sorting, with specific parts needing to be located much like a giant puzzle. An example of this is Zaha Hadid Architects’ Heydar Aliyev Center in Azerbaijan (2012). The continuous surface wrapping the building is a result of the assembly of around 15,000 panels, each with an individually curved geometry, in various sizes up to a maximum of 1.5 m wide and 7 m long. This extensive panel differentiation is common in continuous double-curved surfaces. The software company Gehry Technologies used machine-learning algorithms to rationalise the façade of Fernando Romero’s Soumaya Museum in Mexico (2011).

Developments in large-scale 3D printing are usually associated with the mechanical and material side of the fabrication process.

These include Behrokh Khoshnevis’ Contour Crafting method, in which concrete is extruded from a nozzle mounted on a large gantry-like structure. In recent years, Shanghai-based practice WinSun has advanced a similar 3D-printing process that has produced various full-scale prototypes.

Architects like Ronald Rael and Virginia San Fratello use commercially available 3D printers, such as Z Corp, to develop various printable materials, including ceramics. Their company, Emerging Objects, has also produced a series of large-scale architectural prototypes. In other cases, robots have been used as large 3D printers. Pioneering research

by Marta Malé-Alemany at the Institute for Advanced Architecture of Catalonia (IAAC) focused on robotic processes for additive manufacturing in an architectural context.

Of equal significance is Gramazio Kohler’s research at the Future Cities Laboratory (FCL) in Singapore, which introduced the process of spatial plastic extrusion with

The research for the project stemmed from a wider interest in architecture’s relationship with the digital condition. In the late 1990s and early 2000s, Western European and North American architects, such as Greg Lynn, UNStudio and Zaha Hadid, based their digital designs on the premise of continuous space, as described by Mario Carpo: Designers using spline modelers 'model' reality by converting it into a strippeddown mathematical script, and the continuous lines and uniform surfaces they draw or make are ultimately only a material approximation of the mathematical functions that computers have calculated for them (Carpo 2014).

The first use of 3D-modelling software in the design of architecture pursued the generation of a fluid space with floors that transition into walls and ceilings. Early examples of this concept include Fresh Water Pavilion by NOX Architecture (1997) and Foreign Office Architects’ Yokohama International Passenger Terminal (2002), which adopts fluidity between spaces on multiple levels.

Using digital design software such as Form-Z and, more recently, Autodesk Maya, 3DS Max and Rhinoceros, these architects have generated complex structures and have then tried to post-rationalise their construction to realise them in physical space. In doing so, the continuous surfaces of the digital model are broken down into highly differentiated panels and custom-made structural elements. Digital fabrication tools are brought in as a second stage in the design process but prove more costly than traditional manufacturing methods when applied to the scale of large architectural

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CONTEXT

a robotic arm. The aerospace industry has also been conducting research on robotic metal-sintering processes. Researchers such as Benjamin Dillenburger, Michael Hansmeyer and Softkill Design often use Voxeljet sand printers and other commercially available options to propose large-scale 3D-printed architectures without addressing the actual printing process. Alongside the above, the research references the history of architectural experimentation with novel structures and methods that goes back to Marcel Breuer’s Wassily Chair (1925–6) and Cesca Chair (1928).

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15 Robotic extrusion process for the Ogonori chaise longue at Nagami Design in Avila, Spain.

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Methodology

extrusion equipment. The software executes a basic finite element analysis that abstracts structural data from the imported mesh to determine the type of cell to be used in each voxel. Cells are then instantiated along the voxel space and allocated in response to local compression and tension levels. Two types of cells were used for the first prototype generated using Discrete Design v1.0: a flat cell that generates high-density areas of the material and a 3D cell that supports the flat cells in areas with low density. The former is used in those areas with higher stress, while the latter is used where the stress values are low and a more fragile line fragment is sufficient.

Voxels are grouped by their vertical coordinates into layers of a given height (17).

Flat-cell areas are grouped in sublayers and indexed from bottom up to fill the total voxel height. Each layer and sublayer are represented as an undirected graph.

Their centres are associated with vertices and their orthogonally adjacent cells with edges of the graph. The disconnected graphs connect through the discarded edges. Subsequently, a Hamiltonian path is used to create a sequence of connected cells where each vertex is visited only once (18–21). The cells rotate in two dimensions until an end point of the toolpath fragment connects to the open edge of the previous cell in the sequence. The principal direction of stress is abstracted from the finite element method (FEM) to be assigned as the preferred orientation of the cell when multiple rotations are possible.

Each toolpath fragment of the idealised path is further adjusted to avoid collisions and other possible issues when printing. When neighbouring cells contain overlapping edges they offset inwards by half of the extrusion thickness, which

1. Iterative coding and scriptwriting for new software development

First Version Discrete Design v1.0 was developed in Java programming language and used functionality from the ‘flexible software sketchbook’ Processing by Ben Fry and Casey Reas. Operating within a Cartesian grid, the software generates a voxel space from an imported volume and serialises these voxels according to different criteria, including structural requirements, porosity and transparency. Users can control both the overall mass of the object at the macro-scale and material organisation at micro-scale. Different line fragments inside one voxel can be imported as basic units. A combinatorial algorithm then substitutes each of the voxels in the 3D space for one unit or another and picks the one that best matches the local requirements. The rotation of the units is automated, ensuring connectivity between the end of one line fragment and the start of the next. This ensures the creation of a continuous line that can be printed by a robot equipped with a polymer extruder.

Discrete Design v1.0 (16) approximates the curvilinear morphology of the volume to be filled in an orthogonal manner. First, the Vitra Panton Chair (1967) was modelled in Autodesk Maya. It was then imported into the software as a manifold-mesh object with no self-intersections. A voxel space was generated from its bounding box, with voxels falling outside the mesh being removed. The size of the voxels is modifiable within the range of toolpathsegment lengths, printed with specific

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METHODOLOGY

prevents collisions with the extruded material; it also serves as a boundary between the described segments.

Overhanging fragments are extended towards the previous supported cells to compensate cantilevers. This implies overriding these cells and computing a reconnection with the remaining fragments in the toolpath.

Once the toolpath is computed, a vertex sequence is exported as a csv file.

Discrete Design v1.0 does not offer a bridge between this step and the code that the robot executes but exports this csv file, which will then be imported in Rhinoceros Grasshopper to generate a continuous poly-line. The robot program is generated through the Robots plugin created by Vicente Soler.

16 (overleaf) Discrete Design v1.0 screenshot showing line-fragment distribution in VoxelChair v1.0. The left side is dedicated to visualisation modes, allowing particular layers to be isolated (top), and shows information about the line fragments.

The right side depicts the object’s mass balance, computed layers and located line fragments (top to bottom).

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17 Sequence of layer-bylayer calculations for VoxelChair v1.0 in Discrete Design v1.0.

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18 Visualisation of the Hamiltonian path, which visits all vertices once, in one isolated layer found in the connected subgraphs.

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This is used to arrange the line fragments in the printing process and guarantees continuity in the extrusion.

METHODOLOGY

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19–21 The Hamiltonian path in Ogonori.

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Both prototypes were printed at Nagami Design, a robotic manufacturing company based in Avila, Spain, founded by Manuel and Miguel Angel Jiménez GarcÍa and Ignacio Viguera Ochoa. To accelerate the printing process, especially for line fragments printed in the air, the Nagami team added a vortex tube to the extruder’s cooling system that pours compressed air to the end of the nozzle. This helps lower the temperature and accelerates the cooling process. This system is only activated when material is extruded in the air. Higher-density cells can be extruded at the maximum speed when most of their segments are supported by lower layers with no need for cooling. The signal for when to activate/deactivate the cooling system is embedded in the code of each line fragment in Discrete Design v2.0, whereas v1.0 requires external actuation by a switch.

Second Version Discrete Design v2.0 was fully rewritten in C# using Unity as a framework, with the aim to streamline the generation of the robot program. Although this version does not yet create a full robot program requiring functionality from Robots for Grasshopper and the use of the plugin after the csv file is generated, it integrates 3D-printing constraints and information such as flow rate, speed and retraction points into the generated csv. This allows for a much more streamlined translation into the robot program, without needing to specify those values in the Grasshopper plugin.

The limitations of the equipment can be readily imported as constraints in the second version of the software. As the extruder moves up and down, the geometry of the nozzle is imported to check for possible intersections with the printed segments.

To avoid sagging, segments extruded in a downward direction are printed at lower speeds. Extrusion speed is slightly higher in segments printed upwards, to keep them in tension. A waiting time is also introduced at the end of those segments, as well as a sucking motion effectuated by the extruder controller while the material is cooling down.

To test out the new functionalities of Discrete Design v2.0, a physical prototype was produced in the shape of a chaise longue, inspired by Charles and Ray Eames’ La Chaise for Vitra (1948). The prototype Ogonori evidenced the streamlined communication between the design generation and robotic 3D printing (14).

Discrete Design v2.0 approximates the line fragments in the voxels to the mesh face, achieving a smoother surface that increases comfort and mitigates the 'voxel look' of the object (22).

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22 Digital visualisation of Ogonori, generated with Discrete Design v2.0 and rendered in Keyshot.

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2. Iterative digital prototyping of line fragments

Line fragments were designed and iteratively tested using robotic 3D-printed prototypes. Initial iterations of the Discrete Design software focused on the creation of continuous toolpaths for robotic plastic extrusion. A limited number of discrete units are printed to test the process, which are then instantiated and connected to generate a ready-to-print continuous line.

Once a fragment’s printability has been confirmed in all possible directions, the piece is included in the software to be instantiated throughout the voxel space.

This way, all possible errors inherent in the constraints of spatial 3D printing are tested beforehand to preclude the possibility of unexpected deformations in later, more crucial, stages of the large-scale print.

Multiple toolpath variations can, therefore, be created to fill any given bounding box or volumetric object. This allows for differentiated material density in response to structural conditions, while a combinatorial algorithm allows for differentiated material distribution.

Material density and direction can be locally controlled by changing the scale and orientation of the fragments, producing a gradual differentiation of the strength of the object across its volume (23).

Although this software was initially created for 3D printing, its functionality could easily be used for other manufacturing methods within a Discrete Design methodology, such as the aggregation of bent metal bars or building blocks made out of timber sheets or cast in concrete. As long as a limited number of discrete units is used, and those units fit a voxelspace, later iterations of Discrete Design software could be developed to establish the syntax for their connectivity.

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23 Four line fragments from VoxelChair v1.0. From left to right, the first two show the air-printed lines alternatively distributed in subsequent layer groups where stress levels are low.

The next two fill those voxels in areas with higher stress levels to create a better structural integrity.

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24 Different modes of visualisation to be activated/deactivated in the Discrete Design software, showing the different properties of the line fragments. From left to right: Line fragment end points, directions, fragment vertices (large circles indicate upper vertices, while small circles indicate lower vertices).

METHODOLOGY

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25 Discrete Design v2.0 screenshot showing the line fragment distribution in Ogonori. Left, from top to bottom: File setup, allowing printing and geometrical factors to be changed; visualisation modes displaying different

features of the object and the computed toolpath; toolpath simulation timeline.

Information about the base model and the line fragment in use is depicted on the right.

26 Screenshot showing minimum spanning trees establishing a subgraph with the connectivity of the cells. The elements are ordered in the same direction (corner or straight).

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3. Iterative physical testing using robotically 3D-printed prototypes to serialise and anticipate errors

In its various iterative steps, the research involved both digital prototyping and physical testing. Discrete Design v1.0 was tested in the creation of VoxelChair v1.0, which was commissioned in 2016 by the Centre Pompidou in Paris. The chair uses two different fragment types that are assembled into a continuous 2.36-km toolpath. The Grasshopper plugin, Robots, converts the abstracted program into manufacturer-specific language and then outputs it to the robot controller.

Nagami’s ABB IRB 4600 robot was used to create the VoxelChair v1.0 prototype, and the pellet extruder – proprietary technology of Nagami – was specifically developed for this project. VoxelChair v1.0 established the computational principles necessary to aggregate linear elements in response to structural parameters.

Discrete Design v2.0 was first used for the creation of the Ogonori chaise longue.

The same two types of line fragments were used for this prototype, however, those in boundary voxels were deformed to better match the curvature of the object. This demonstrated the added functionality of the software. As most necessary printing information is already embedded in the output of Discrete Design v2.0, Robots for Grasshopper serves as a mere intermediary to translate the csv file into a robot program that can be imported into the controller of Nagami’s ABB robots.

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27 Robotically 3D-printed samples, realised at Nagami, with different types of PLA, colourant and tones.

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28–9 PLA robotic-extrusion process at Nagami. The chair is printed in two halves, rotated 90 degrees and assembled with the same PLA and colourant used in the printing process.

30–1 Robotically 3D-printed samples, realised at Nagami, with different types of PLA, colourant and tones.

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32 Detail of PLA roboticextrusion process at Nagami.

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33 Collection of robotically printed VoxelChair variations, configuring a landscape of different material organisations.

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4. Reviews, lectures and seminars to ensure continuous peer feedback and knowledge exchange

The project has formed a catalyst for cross-faculty knowledge sharing and discussion within UCL and other institutions. An informal dialogue with researchers from The Bartlett’s Architectural Design and Architectural Computation courses was initiated to explore how digital design and fabrication strategies can be further integrated and developed in a series of related IT and engineering disciplines. Discrete Design software has been especially relevant in the research that Design Computation Lab has developed within UCL, serving as inspiration for a large variety of projects focusing on robotic additive manufacturing using discrete methods.

The evolution of the software has been undoubtedly linked to the experience gained in such projects. Much of the functionality added to v2.0 collects technical requirements observed in the creation of robotically printed prototypes, which the lab has generated over the last five years of 3D-printing research.

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34–5 PLA robotic extrusion of VoxelChair v1.0, created for the Philadelphia Museum of Art. The same ABB 4600 robot was used, painted white, along with Nagami’s third-generation extruder for robotic plastic extrusion.

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Dissemination

Publications

VoxelChair v1.0 and Discrete Design v1.0 and 2.0 have been positively reviewed in Wired, as well as online on Digital Trends, Commercial Interior Design and 3D Printing. The authors have written about the research in Discrete: Reappraising the Digital in Architecture for Architectural Design and six other publications (included in the Appendix).

Exhibitions

VoxelChair v1.0 and Discrete Design v1.0 have been exhibited at: · Designs for Different Futures, Philadelphia Museum of Art (2019) · Digital Turn, Design Computation Lab, The Building Centre, London (2018) · KANAL Centre Pompidou, Brussels (2018) · Imprimir le monde, Centre Pompidou, Paris (2017)

Media Documentaries

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Ogonori was exhibited at: · 3D Pioneers Challenge, Messe Erfurt (2018)

Lectures

GarcÍa and Retsin have lectured on the subject at the following conferences, seminars, invited talks and lectures: · Global Grad Show, Dubai (2019) · Iconno, Madrid (2019) · Norman Foster Foundation, Madrid (2019) · Rebuild Congress, Madrid (2019) · American University of Sharjah (2018) · Audi Innovation Hub, Dubai Design Week (2018) · eCAADe, Rome (2017) · MIT, Cambridge, Mass. (2017) · The Bartlett School of Architecture, UCL (2017) · University of Michigan (2016) · University of Stuttgart (2017) · Universidad Politécnica de Madrid (2017)

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Robots can build entire cities almost for free. These architects are making it happen (2018). Produced by Mashable.

[Viewed 4 December 2020]. https://mashable.com/video/designcomputation-lab-gilles-ritsin-manuelgarcia-architecture-future-robotics/ ?europe=true VoxelChair v1.0 + Ogonori (2019). Produced

by Design Computation Lab and Nagami Design. [Viewed 4 December 2020]. https://vimeo.com/273004824 3D Printed Chair Voxel (2017). Produced

by UPHIGH Productions.

[Viewed 4 December 2020]. www.youtube.com/watch?v=oo0w PJKTOek

DISSEMINATION / PROJECT HIGHLIGHTS / BIBLIOGRAPHY

Project Highlights

Bibliography

VoxelChair v1.0 is now part of the permanent collections of the Centre Pompidou, Paris, and the Philadelphia Museum of Art. Ogonori won a ‘Special Mention’ in the 2018 3D Pioneers Challenge exhibition in Erfurt. Further to this, the authors won the ACADIA Autodesk Emerging Research Award in 2016 for their paper ‘Discrete Computational Methods for Robotic Additive Manufacturing: Combinatorial Toolpaths’.

Carpo, M. (2014). ‘Breaking the Curve: Big Data and Design’. Artforum. 52 (6). pp. 169–73.

Contour Crafting (2017). Contour Crafting.

[Viewed 12 August 2020]. https:// contourcrafting.com/ Retsin, G. (2017). ‘A Robot Built the Utterly Unique VoxelChair from a Single Strand of Plastic’. Digitaltrends. 22 May. [Viewed 19 August 2020]. www.digitaltrends.com/cool-tech/robotprinting-chair-continous-plastic/

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36

37 VoxelChair v1.0 exhibited at the opening show of KANAL – Centre Pompidou in Brussels, 2018.

36 Second print of the VoxelChair v1.0 for Designs for Different Futures at Philadelphia Museum of Art, 2019. The photo shows the 'New Materials' section, where the chair was displayed.

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38 VoxelChair v1.0 exhibited at Imprimir le monde, Centre Pompidou, Paris, 2017. The piece subsequently became part of the museum’s permanent collection.

DISSEMINATION / PROJECT HIGHLIGHTS / BIBLIOGRAPHY

37

38

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Related Publications by the Researchers Jiménez GarcÍa, M. (2019). ‘Discrete Flexibility: Computing Lightness in Architecture.’ Retsin, G. ed. Discrete: Reappraising the Digital in Architecture (Architectural Design). 258. Hoboken: John Wiley & Sons. pp. 70–7.

Jiménez GarcÍa, M. and Retsin, G. (2015). ‘Design Methods for Large Scale Printing.’ Real Time: Extending the Reach of Computation. 2. eCAADe and Faculty of Architecture and Regional planning, TU Wien. pp. 331–9.

Jiménez GarcÍa, M. and Retsin, G. (2016). ‘Discrete Computational Methods for Robotic Additive Manufacturing.’

Velikov, K. ed. Acadia 2016 Posthuman Frontiers: Data, Designers and Cognitive Machines: Projects Catalog of the 36th Annual Conference of the Association for Computer Aided Design in Architecture. Acadia Publishing Company. pp. 332–41.

Jiménez GarcÍa, M., Retsin, G., Soler, V. (2016). ‘From Continuous to Discrete Fabrication.’ Clark, B. and Spaven, R. eds. AAE 2016: Research-Based Education. The Bartlett School of Architecture, UCL. pp. 231–42.

Jiménez GarcÍa, M., Retsin, G., Soler, V. (2017). ‘A Generalized Approach to Non-Layered Fused Filament Fabrication.’ Lamere, J., Parreno Alonso, C. eds. Acadia 2017 Disciplines and Disruption: Projects Catalog of the 37th Annual Conference of the Association for Computer Aided Design in Architecture. Acadia Publishing Company. pp. 2–11.

Jiménez GarcÍa, M., Retsin, G., Soler, V. (2017). ‘Robotic Spatial Printing.’ Shock! Sharing of Computable Knowledge!. 2. eCAADe and Faculty of Architecture and Regional planning, TU Wien. pp. 143–50.

Jiménez GarcÍa, M., Retsin, G., Soler, V. (2019). ‘Voxel Chair 1.0’.

Claypool, M., Jiménez GarcÍa, M., Retsin, G., Soler, V. eds. Robotic Building: Architecture in the Age of Automation. Munich: Detail. pp. 66–7.

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RELATED PUBLICATIONS

Related Writings by Others Ahmed, R. (2017). ‘Designers at UCL 3D Print Voxel Chair From Single Strand of Plastic’. 3D Printing.

Cambridge Network (2017). ‘Built by Robots, Printed in Air’.

Cambridge Network. 9 November.

Dormehl , L. (2017). ‘A Robot Built the Utterly Unique VoxelChair from a Single Strand of Plastic’. Digitaltrends. 22 May. Lasoutdp1719 (2018). ‘Voxel Chair v1.0, Manuel Jiménez GarcÍa et Gilles Retsin, 2016’. Lasoutdp1719. 13 January.

Saunders, S. (2017). ‘DCL Researchers’ New 3D Printing Software Used to Design Voxel Chair 3D Printed with a Continuous Line of Material’. 3D Print. 23 May. Wired (2017). ‘Software Furnishings’. Wired. October. p. 70.

3D-Druck (2017). ‘Bartletts 3D-Design-Software schafft “Voxel Chair” au seiner durchgehenden Linie’. 3D-Druck. 19 May. 3D Natives (2018). 'Nagami, Exploring the Design of the Future with New Technologies'. 3D Natives. 13 July.

Printed article

Online article (clickable link)

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