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.