Paste Deposition Modelling (PDM): A hybrid ALM/craft process

Abstract

According to David Pye handwork can be understood as 2 aspects of workmanship: workmanship of certainty and workmanship of risk. Craft, he argues typically falls into workmanship of risk owing to the uncertainty of the outcome caused by lack of control over materials and processes.

The Aalto vase is an example of risk workmanship this design has evolved over several decades, It was originally made using wood moulds; this made each batch of vases unique due to the decay of the mould it brought unique parametric changes to each vase.

This is in sharp contrast to Additive Layer Manufacturing (ALM) where the materials and the process are developed to the point of certainty. So, how in such a controlled process can we add elements of risk and uncertainty akin to craft? would applying craft thinking give added value to the artefacts?

The development of an artefact through design software allows the designer-maker to attain a high degree of refinement, cultivating a design can take several days. Has the relationship between maker and artefact shifted to a virtual plane?

"'Contemporary craft is about making things. It is an intellectual and physical activity where the maker explores the infinite possibilities of materials and processes to produce unique objects."
(Greenlees.R)

Makers in the realm of digital craft such as Drummond Masterton (2007) have explored the idea of disrupting CNC machine code to add aesthetic qualities, using machining marks as a primary design feature.

Materiality is essential to craft thinking, what materials are selected and how they are treated is of great relevance. In some ways current ALM processes have inadvertently through delivering design freedom, limited this creative enquiry by reducing the palette of materials available to the designer-maker.

Paste Deposition Modelling aims to increase this palette and open ALM to experimentation, it relies on hacked together hardware and subverts software to explore syringe based 3D paste deposition. This approach enables designer-makers to 3D print with almost any material.

Craft materials like Precious Metal Clay (PMC) offer an opportunity to explore ALM in a context that is not normally associated with, uncertainty. PMC is known for its unpredictability; variables in size, and firing temperatures can influence the final outcome. PMC in clay form can be adapted for PDM using simple tools. Whilst a layered filament texture is evident from the process, it can be blended and made smooth, according to the designer’s intention, it can also be exaggerated and exploited in a similar way to Masterton's work leading to a more honest outcome of the process.

Silicones are easier to predict and when considering the final form offer very little uncertainty . However the materiality of the build is far less predictable, it has surprising optical, structural and tactile qualities. Subtle differences in the internal structure can deliver great changes to the overall feel of the artefacts.

The process is much more open to 'happy accidents' where the material can be led to behave in unpredictable ways leading to stochastic features not reflected in the virtual design stages.

PDM exists in three domains; digital, code craft, and traditional practice. This brings about a process that can be a hybrid in that it is ALM yet regains the nature of being ‘touched by hand’.

Greenlees. R. what is craft. Available: http://www.vam.ac.uk/content/articles/w/what-is-craft/. Last accessed 10th May 2013.
Masterton, D., H., (2007), ‘Deconstructing the digital’, Proceedings of the New Craft Future Voices Conference, pp. 7-24