Appropriate design of human powered press for straw bale construction in poor contexts

The design of intermediate machines, aimed to improve the well being of poor, marginalized or under served communities, require a systemic approach. In the paper, this kind of methodology is applied to the design of a manually operated press for the production of straw bales for straw bale construction in developing countries. Starting from the analysis of the context, the design specifications of the press are discussed. Based on economic and social constraints, a closed compression chamber baler, with slider crank actuation mechanism, is proposed. The transmission mechanism is optimised, in order to reduce the peak of the operating force. Finally, the detailed design and the prototype of the baler, is presented. The field tests of the prototype proved that the solution is appropriate for the purpose.