Design and fabrication of specialized wrench for confined spaces application

Wrenches are essential tools in maintenance and assembly work, but conventional designs often prove ineffective in confined environments such as under sinks, where reach and flexibility are limited. This study aims to design and fabricate a specialised wrench that enhances usability in such restricted conditions. The research began with a user survey to identify key usability challenges experienced in real-life working environments. Design requirements were then derived using the Quality Function Deployment (QFD) method, which helped prioritise user needs and technical specifications. Conceptual designs were generated using the TRIZ methodology and a morphological chart to explore innovative solutions. Three conceptual wrench designs—A, B, and C—were developed and evaluated through a weighted decision matrix based on criteria such as grip, adjustability, manufacturability, and suitability for tight spaces. Among the three, Design A achieved the highest score and was selected for further development due to its potential to significantly improve grip, ease of adjustment, and accessibility in confined areas. The selected design was modeled using SolidWorks CAD software, prototyped using 3D printing, and then fabricated through the sandcasting method, utilising Aluminium 6063 due to its favorable strength and weight properties. Post-fabrication processes included surface finishing and visual inspection to assess porosity and ensure surface quality. Real-environment testing was conducted under a sink setup to evaluate the performance of the developed wrench compared to a conventional wrench. The results demonstrated that the newly developed wrench provided superior handling, better access, and increased efficiency. In conclusion, this study successfully developed a functional tool suitable for use in confined spaces.