Social sustainability is a growing concern for supply chain management, but questionable practices endure due to insufficient stakeholder pressure on the market leading firms. Meanwhile small, socially oriented firms may have the will but lack the means to change dominant practices when entering a market. In this context 3D printing may offer a solution, by leveraging the voluntary effort of individuals through open design and distributed production. A system dynamics approach is applied to the case of a socially oriented mobile phone producer, whose fair supply chain practices may initially appeal only to a niche market. We examine how open design of 3D printed mobile phone accessories helps overcome size-related resource constraints, facilitate market growth and ultimately generate sufficient consumer demand to alter the market leaders’ supply chain practices, in favour of social sustainability. Our findings demonstrate the interaction between availability of 3D printers, consumer attitudes to social sustainability and the market entry. We discuss the implications for technology management, namely that 3D printing can help overcome resource constraints to support the diffusion of socially sustainable supply chain innovation.