In the early days of Fablabs and other digital fabrication spaces (e.g. hackerspaces, makerspaces), these community spaces that offer public, shared access to high-end manufacturing equipment (e.g. 3D-printers, laser cutters) were often described as having the democratizing potential to empower everyone as future makers. However, research showed that non-expert users are often impeded to engage in such spaces due to various challenges (among other things, the unfamiliarity of available tools and machines, a lack of skills and experience). By describing a case study in which we elucidate different strategies that were used to engage non-expert users in FabLab Genk, this paper focuses on the mediating role of the design researchers who become part of a non-expert user community. This allows the design researchers to negotiate between the existing practices of the community and the potential of a FabLab. Furthermore, the case-analysis stresses the importance of networks of peers for opening up FabLabs for non-expert users. We also emphasize the complementarity between different strategies that can be employed to engage non-expert users in a FabLab. By highlighting these findings, the papers shows how a FabLab's shift towards community building can change the focus on the technical and spatial infrastructure towards social infrastructures, which is essential for engaging non-expert users.