Study of Effective Hinge Thickness of Additive-manufactured Flexure Mechanisms

Additive manufacturing is providing great potential for developing complex flexure mechanisms and hence has become research focus recently. In the existing researches, various thickness correction factors were introduced to correct the thickness deviation of the 3D-printed flexure hinges. The reasons for the different correction factors between designs are not clarified and result in limited suggestions for future development and analysis. This paper focuses on clarifying how the variation of thickness correction factors happen in previous studies. The sample design, fabrication, measurement and tests are detailed where the manufacturing process conditions and the original thickness of design are mainly considered. The results suggest that the deviations of hinge thickness are mainly caused by an external layer on the surface formed by the melted particles during the manufacturing process. For the design and development of flexure parts intended for 3D-printing with customized process conditions, the effective hinge thickness could be described better by a stable thickness deviation than the effective thickness ratio.