This paper presents the design and development of a low-cost Computer Numerical Control (CNC) milling machine aimed at promoting sustainable digital manufacturing in resource-limited settings. The system incorporates readily available components including an Arduino Uno microcontroller, CNC shield, stepper motor drivers, and open-source control software (gSender). With a working area of 40 × 40 cm, the prototype is capable of processing wood, acrylic, and soft metals. Compared to commercial CNC systems, this model significantly reduces cost while maintaining acceptable levels of accuracy and functionality. The paper details the mechanical and electrical architecture, design considerations, implementation steps, and performance evaluations. Findings demonstrate the feasibility of building a reliable and affordable CNC platform with broad applications in education, prototyping, and small-scale production.