Domenico.cc - A digitally fabricated geodesic construction system

Description

Fab Lab Limerick from the School of Architecture at UL in collaboration with the Spanish-Irish design agency Colaborativa.eu is researching about the potential of digital fabrication and open source methodologies to generate low-cost construction systems. These systems are adequate for distributed manufacturing methods and can be used by the communities to self-build temporary collective spaces. We want anybody to be able to build strong, affordable and locally made geodesic buildings.

In the summer of 2013, it was developed a first prototype for temporary structures based on low-cost components and digital fabrication. This first geodesic dome was based in bamboo struts and 3d printed bio-plastic connectors. The assembly was carried out by three people in less than two hours and the prototype had an approximate cost of 4€ per square meter.

In August 2014, Colaborativa.eu partnered with Fab Lab Limerick to develop a second iteration of the design, following the same principles of low-cost and digitally fabricated but using cardboard tubes and digitally fabricated plywood connectors instead. This change of materials allowed bigger domes with a span of up to 14 meters and 150 square meters covered area. This year Colaborativa.eu and Fab Lab Limerick are developing a deck and an inflatable cover for the dome.

Paper tubes have great mechanical properties if they are kept with low moisture content –an increase of just 1% of moisture content produces a loss of strength of around 10%– therefore finding a viable method for waterproofing the paper tubes is crucial. A two-step method has been found: first a moisture barrier ply is included below the first few paper layers, this waxy layer prevents moisture from penetrating deeper into the the paper tube. The second step is to apply an external waterproofing layer of a low volatile organic compound polyurethane. A more environmentally friendly solution is being considered for the next iteration of the prototype.

A plywood hub detail is based on two principles. First, it had to be able to be rapid prototyped using laser cutting so each design iteration could be cut and tested at 1:1 scale as quickly as possible. Second, the hub needed to support the position of the paper tubes rigidly during the assembly process as the whole system was meant to be assembled without the need of auxiliary structures such as cranes, scaffoldings or additional supports.

The design offers a great resistance to wind and snow loads and can span up to 14 meters using very small and light elements. The system consists in a continuous tension, discontinuous compression structure of cardboard tubes connected by CNC cut plywood hubs which were developed in a fast iterative design process using laser cutting.

We believe that full-scale structural systems using Fab Labs for both rapid prototyping and manufacturing could open up innovation in building technology to communities all around the world

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Scope

This project explores the possibility of self-build collective and temporary spaces in the public space. This type of system can expand the type of activities citizens perform in the public space and, for example, test the success of public facilities in an experimental way before using more permanents building systems.

Frequently, years will go by before communities can take care of their collective space necessities. Usually, the goal of community self-build projects is a permanent building which requires a considerable amount of planning and financial resources. By self-building a temporary collective structure the community could enjoy all the benefits of a collective self-build project which can be started in a very early stage of the community development and ensure a healthy development for the community.

This could represent a more organic and decentralized approach to city equipment design in which physical infrastructures not only represent existing communities but help to create and strengthen those communities at an early stage.

Discuss this Project on discuss.fablabs.io