Collective activities such as crowdfunding, competitions, jams and hackathons are gaining more attention in innovation management. However, within the design domain such activities are often considered as a way for mass generation of ideas, rather than processes for developing proper design solutions. Information acquisition, gaining sufficient knowledge and generating feasible ideas are among the main challenges of collective design. In this study we applied three strategies of rapid design, informed participation, and knowledge sharing to overcome these challenges. During a one- week design hackathon, we conducted a collective design project in which three teams of participants conducted autoethnography research, shared their findings by an idea crowdsourcing platform, and tested their 3D printed prototypes with potential users. Although the tests showed efficiency of rapid design and informed participation strategy, we did not find knowledge sharing effective, mainly due to the absence of collaboration among teams.