Application of rapid prototyping (RP) techniques such as stereolithography, fused deposition modelling and selective laser sintering in the development of complex engineering systems is on upsurge due to associated functional advantages such as time-compression, design-freedom and mass-customisation. This paper examines the feasibility of using various RP techniques for fabricating light-weight flapping wing mechanisms for subsequent use in bird-mimicking micro aerial vehicles called ornithopters. These mechanisms need to fulfil conflicting set of requirements related to compactness, low weight, high transmission efficiency and adequate structural integrity. In this work, the versatility of RP techniques is leveraged for fabricating transmission shaft, linkages and gearbox housing of dual crank mechanism that powers four-winged biplane ornithopters. The fabricated mechanisms are integrated into ornithopters and tested in customised rigs. Results on RP mechanisms are compared with those of conventionally manufactured mechanisms with focus on aerodynamic performance, strength and ease of assembly. Results indicate that RP mechanisms of biplane ornithopters that weigh about 4.50 gm can sustain the flight loads during take-off, climb and landing phases. Through integration of modern direct digital manufacturing techniques into design iteration and fabrication of flapping mechanisms, the reported work opens up new vistas in the development of new generation of ornithopters.
International Journal of Modern Manufacturing Technologies 9(2), p.18-22