Rapid manufacturing of high reduction polymer gears by use of stereolithography

High reduction gears are used for small drives in a variety of applications in mechatronics. If the shape and the size of these actuators vary greatly, additive fabrication techniques can help to produce end-use parts directly from digital data to reduce the costs of special gears considerably. The focus of this study is to fabricate rapidly high reduction gears on demand, optimized to an automation task and at low cost. Generic models are applied to modify the sizes of a harmonic drive gear or a cycloid gear parametrically. Stereolithography is applied for the direct manufacturing of the gear components within hours. The accuracy of the stereolithography process is evaluated relating to a miniaturization of the gear. Different types and sizes of high reduction gears were fabricated and tested and the results are presented in this paper.