This paper explores how the Engineering Design process might balance conflicting constraints of technical product design and the social demands of users. Building on a generic 2D map for innovation in design from the author's previous work, a prototype 3D Diamond Model is presented to help structure conversations between Designers and Users -or indeed any other group with apparently opposing aims. In theory, the model draws on the structure of Buddhism (in particular the Mandala of the Five Buddha Families) and managerial cybernetics (in particular Beer's Viable System Model and his Team Syntegrity protocol), to establish how one's worldview might evolve and how a common worldview for two teams can be determined. In practise, a Facilitator or Researcher helps Designers and Users achieve their respective aims, and develop a common one. When a common worldview is achieved, conversations and activities can become mutually informing, coevolving and emotionally satisfactory at both the individual and team levels.