We read with great interest the article 'Design and build' (AJ 15.3.01) on rapid prototyping and its possible uses for architecture. In the run up to the millennium, we used this process extensively for the production of cast steel nodes for Antony Gormley's Quantum Cloud sculpture adjacent to the Millennium Pier outside the Dome.
Due to the complex geometry of the primary structure, with differing angles and rotations at the node connections, all 364, four-way connecting nodes were unique. This, together with technical requirements for the joints, presented enormous difficulties as the sculptor was adamant that the nodes should not appear any different to the remainder of the structure.
This prevented the use of traditional space frame-type connections.
After much research, rapid prototyping was found to be the only cost- and time-effective way of producing the nodes.
As the whole structural model had been created digitally, the rotations and angles were predefined and therefore the nodes could be readily developed into solid three-dimensional computer models.
Considerable efforts were made to find resources to produce the rapid prototype models that could then be used in a 'lost wax' process to produce the final nodes. With the great help of Innovative Manufacturing Centre (IMC) at the University of Nottingham, the prototypes were produced on time and on budget using MultiJet Modelling (MJM) and Laminated Object Manufacture (LOM).
Due to the limited space and the time taken to create each model, the nodes were optimized so as many as possible could be developed within the model volume. This necessitated splitting the nodes into bodies and spigots. As the spigots were all identical they were made using standard tooling techniques, and then glued in place prior to 'lost wax' casting, thus speeding up the process.
We believe this was the first project in the UK to use rapid prototyping on a large scale for full production purposes.
Gary Elliott, Elliott Wood Partnership, London SW19