COMPUTING CRAFTManufacturing Cob Structures Using Robotically Controlled 3d PrintingConcluding remarks
Connected Everything: Industrial Systems in the Digital Age Conference - Nottingham - 25 June 2019
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Introduction
Material exploration
3D printing equipment
Material extrusion system
Geometry and performance explorations
Future work
Subsoil
Straw
Water
Cob
Cob house in Dartington village in England. (CobBauge, 2018)
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Regions with abundant clay in soil
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Where Can You Build with Cob?
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ODA Countries and Territories
The investigation was conducted in three stages:
• Investigate the current knowledge base of craft-
based cob-construction.
• Conduct initial geometrical and performance
exploration through small-scale modelling.
• Conduct a full-scale feasibility test for a cob
building element (building a wall/module).
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The scheme of large scale robotic 3D printing set up (Gosselin et al. 2016)
3D printing
Equipment
Design &
Performance
Material
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Material Exploration
Cob recipes are location-dependent.
Weismann, Adam and Katy Bryce. Building with Cob: A step-by-step guide, 40 – 65. Devon: Green Books Ltd, 2006.
On-site testing is always required.
Subsoil properties
80 % fine aggregate (sand, silt) + 20 % Clay
Subsoil 78% + water content 20 % + Straw 2 %
Cob recipe (by weight)
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3D printing Equipment
Material extrusion system
3D printing Equipment
A
Air-assisted Extrusion
system
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Material extrusion system
3D printing Equipment
B
Mechanical Extrusion system
(3D potter 7- Linear ram extruder)
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Challenges
3D printing Equipment
Constant extrusion
Continuous flow
Higher speeds
Larger scale
Freedom of movement
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Material extrusion system
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Material extrusion system
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Material extrusion system
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Geometry and performance explorations
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Small scale (1:4)
Simple geometries
Geometry exploration
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Small scale (1:4)
Complex geometry A
Geometry Exploration
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Small scale (1:4)
Complex geometry B
Geometry Exploration
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Performance Exploration
Thermal conductivity (W/mK)
• The heat flow rate through a material.
• Lower thermal conductivity is
normally desired. Good practice: 0.6
W/mK.
• The heat flow meter used is a
Netzsch HFM 446.
Prototype 2 (0.32)
Prototype 4 (0.37)
Prototype 3 (0.40)
Prototype 1 (0.48)
Manual cob block (0.84)
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1250.0 1350.0 1450.0 1550.0 1650.0 1750.0 1850.0C
onductivity W
/mK
Density Kg/m3
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Performance Exploration
Thermal conductivity
• Presence of air gap(s)
lowered the conductivity of
the solid 3D printed cob
samples.
• Straw filling in the air gap(s)
further lowered the thermal
conductivity 2
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Bigger scale (1:1)
Geometry Exploration
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Bigger scale (1:1)
Geometry Exploration
Publications
• Veliz Reyes, A., Jabi, W., Gomaa, M., Chatzivasileiadi, A., Ahmad, L. and Wardhana, N.M. 2019.
Negotiated matter: a robotic exploration of craft-driven innovation. In Press. Architectural Science
Review Journal.
• Gomaa, M., Carfrae, J., Goodhew, S., Jabi, W. and Veliz Reyez, A. 2019. Thermal performance
exploration of 3D printed cob. Architectural Science Review 62 (3).
• Veliz-Reyes, A., Gomaa, M., Chatzivasileiadi, A., Jabi, W. and Wardhana, N. 2018. Computing
craft: development of a robotically-supported 3D printing system for cob structures. Presented
at: 36th annual Education and research in Computer Aided Architectural Design in Europe
(eCAADe) 2018, Lodz, Poland, 17-21 September 2018.
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Future work
• Apply the technology in developing countries.
• Explore new material configurations.
• Explore new design and geometric opportunities.
• Conduct further performance testing (e.g. structural etc. on 1:1 scale).
Thank [email protected]
