Design and Fabrication of a Stair Climbing Wheelchair
China, Japan and United State companies has designed and developed many types of stair climbing wheelchair, yet the prices are at average of RM40k, high enough to buy a low end car in Malaysia. The high price of the products mainly due to the complex mechanism and parts that implemented in the wheelchair. Therefore, the intention of this project is to help disable patients by research and design the stair climbing wheelchair with lower cost. This project aims to design, stress analysis and fabricate the wheelchair with only manual mechanical mechanism that used in climb up the staircase. Based on literature review on recent climbing mechanisms and research about the stair climbing wheelchair title, advantages and disadvantages of those concept was pointed out. With the investigation of the recent stair climbing related component and research, three conceptual design was developed by using conceptual solution listing table. By following the flow of engineering design, the conceptual screening helped in selection of initial design. The final design was consisted of clusters climbing mechanism, extendable front wheel and adjustable seat. The dimension of the cluster was set to be length of the cluster, 174.55 mm, radius of the outer curve, r, 70 mm, thickness of the bar, 70mm, with composited material of split aluminium and plywood. The consideration, testing and improvement was done in each stage of fabricating full scale prototype. For example adding limit block for extendable front wheel and optimising the plywood side panel. As the unexpected tip force presented on plywood side panel, the final test was focused on functionality, mechanism workability and dynamic stability of the prototype. The result was promising with smooth motion observed. The costing of the prototype also shows a lower value from expecting. The fetch ability of the wheelchair can be obtained with changing the material of the side panel in the future.