The scope of this development encompasses the entire lifecycle of gear reducer development, from initial design conception to performance evaluation. The design process will involve computer-aided design (CAD) modeling and finite element analysis (FEA) to optimize the gear geometry for strength, efficiency, and reliability. The gear reducer will be fabricated using a three-dimensional (3D) printing process with acrylonitrile butadiene styrene (ABS) material, with careful consideration given to process parameters and post-processing techniques to ensure dimensional accuracy and surface finish. However, it’s important to recognize the inherent limitations of 3D printing technology, including material properties, dimensional accuracy, and surface finish. While ABS is chosen for its favorable mechanical properties, such as strength, durability, and thermal stability, it’s essential to acknowledge its limitations and potential impact on gear performance. Moreover, the development will focus on a specific type of 3D printing technology and material, limiting the generalization of results to other additive manufacturing methods or materials. The primary objective of this study is to leverage the capabilities of 3D printing technology to design, fabricate, and evaluate a single-stage gear reducer. Specifically, the project aims to explore the feasibility of using 3D printing with ABS material to produce functional gear reducers with efficient torque transmission, high-speed reduction, and satisfactory durability. By harnessing the advantages of additive manufacturing, the development seeks to demonstrate the potential of 3D-printed gear reducers to address the limitations of traditional manufacturing methods and unlock new opportunities for innovation in mechanical engineering.