Case of a RepRap-Based, Lego-Built 3D Printing-Milling Machine

From P2P Foundation
Jump to navigation Jump to search

Full reference: Kostakis, V. & Papachristou, M. (2013). Commons-based peer production and digital fabrication: The case of a RepRap-based, Lego-built 3D printing-milling machine. Telematics & Informatics.


This essay set out to show, through the case of the RepRap-based, Lego-built 3D printing-milling machine, two points: First, on a theoretical level, that modularity, not only in terms of development process but also of hardware components, can catalyze CBPP’s replication for tangible products enabling social experimentation, learning and innovation. Second, that the synergy of a globally accessible knowledge Commons as well as of the CBPP practices with digital fabrication technologies, which are advancing and becoming more and more accessible, can arguably offer the ability to think globally and produce locally. Of course, there are several 3D printers as well as CNC machines on the market; however, through our case study, it became obvious how the synergy of CBPP practices and tools with modular hardware components can offer innovative, novel products, such as a hybrid 3D printing-milling machine. When hardware becomes modular, we saw and discussed how individuals – no matter their age, level of expertise and initial skills – could engage in stigmergically collaborative productive processes of designing, programming and manufacturing. The parts and components of modular objects could be re-used for their own improvement or for the design of other products, enabling collaborative (and thus incremental) innovation within hardware construction. Taking into consideration the trends and trajectories of the current information-based societies, the fact that a non-expert can take advantage of a peer produced knowledge Commons and of very elementary digital fabrication capabilities and become capable of developing such a sophisticated machine, in collaboration with others, can be considered a positive message indeed.

Commons-based peer production and modularity (excerpts):

CBPP projects produce use value, i.e. an informational good (e.g. software, design, cultural content) free to use, modify and redistribute, part of the knowledge or cultural Commons. In addition, CBPP’s development processes are based on the self-selection of tasks by the participants, who cooperate voluntarily on an equal footing (as peers) in order to reach a common goal. It has been claimed (see only Benkler, 2006; Bauwens, 2005; Tapscott and Williams, 2006; Dafermos and Söderberg, 2009) that modularity is a key condition for CBPP to emerge: ‘Described in technical terms, modularity is a form of task decomposition. It is used to separate the work of different groups of developers, creating, in effect, related yet separate sub-projects’ (Dafermos and Söderberg, 2009: 61). Torvalds (1999), the instigator of the Linux project, maintains that the Linux kernel development model requires modularity, because in that way people can work in parallel. Empirical research (see only MacCormack et al., 2007; Dafermos, 2013) shows that modular design is characteristic not just of Linux but of the FOSS development model in general. ‘The Unix philosophy of providing lots of small specialized tools that can be combined in versatile ways’, Carson (2010: 208) writes, ‘is probably the oldest expression in software of this modular style’. We also observe the same approach in the development of one of the most prominent CBPP projects, that of the free encyclopedia Wikipedia. Articles (i.e., modules), which are consisted of sections (i.e., sub-modules), are built upon other articles and entries produced and, thus, can be used individually as well as in combination.

Desktop manufacturing and digital fabrication (excerpts):

Neil Gershenfeld (2007, 2012), who is the head of MIT’s Center for Bits and Atoms, notices that the real revolution will be in the programmability of fabrication to the physical world. An interesting comparison, which Gershenfeld (2012) points out, is the performance of a child assembling Lego and a typical 3D printer. In 3D printing a certain object is created by the building up of multiple patterned layers based on a 3D model (Hiller et al., 2011). There are many types of 3D printing, for example laser sintering, stereolithography, electron beam melting and fused deposition modeling (Hiller et al., 2011). Gershenfeld (2012) argues that the child’s assembly of Lego can be more accurate than the child’s motor skills would allow, because the pieces fit together intuitively since they are designed to snap in alignment: the bricks enforce constraint and, thus, accuracy. For Gershenfeld (2012), Lego exemplifies the digitization of material celebrating modular design, while conventional 3D printing represents just an analogue process, which often accumulates errors, based on digital files. ‘In comparison to traditional (analog) 3D printing in which material is deposited or solidified in an inherent continuum’, Hiller and Lipson state (2009:137), the digitization of material imposes finite resolution: ‘the size of a single unit’.

Therefore, Gershenfeld (2007, 2012) proposes a different approach to 3D printing, viewing fabrication as a digital rather than a continuous process. An adjunct to the idea of 3D printing is investigated and tested based on the concept of ‘‘voxel’’ (Hiller and Lipson, 2009; Hiller et al., 2011; Lipson and Kurman, 2013). According to Lipson and Kurman (2013: 16):

A voxel is the physical equivalent of a pixel. Voxels could be tiny, discrete pieces of a solid material. Or voxels could be tiny containers that hold whatever you put into them. (. . .) Objects made of voxels offer an alternative to the analog materials that comprise most physical things. If you can make something from voxels, you’re one step closer to making it behave more like a programmable object, to controlling its behavior. Control over material composition of physical objects opens the door to the next stage, control over the behavior of physical objects.

Hence, any object (module) that has modularity and repeatability in its use to render a larger unit can be considered a voxel. The modularity enabled by voxels can help us create objects with completely different material properties such as strength, flexibility and/or functionality (Hiller and Lipson, 2009).


To sum up, we see that the voxel-based approach introduces modularity in hardware components digitizing desktop manufacturing and arguably enhancing its capabilities. Through our case study we will try to show how it can assist individuals to engage in production processes of collaborative designing and manufacturing. According to all the bibliographical resources cited above, Lego represents a typical, illustrative case of the voxel-based approach to physical manufacturing. Of course, one of the biggest challenges of digital fabrication concerns the processing of large numbers of voxels fast and accurately (Hiller and Lipson, 2009; Lipson and Kurman, 2013). In that way, eventually, it will be possible to print conductors within nonconductors, or in other words to move from ‘printing passive single-material parts to printing active, multimaterial integrated systems’ (Lipson and Kurman, 2013:272). It is evident that since we will have the ability to print in voxel- based 3D printers physical things that contain the intelligence of digital things (Lipson and Kurman, 2013; Gershenfeld, 2007, 2012), the role of knowledge and design becomes even more important. And therefore, the conjunction of CBPP with digital fabrication arguably reaches a new plateau concerning the ability, in Gershenfeld’s words (2007, 2012), ‘to think global and produce local’.

More Information