This study presents the design and structural analysis of a cost-effective mini CNC milling machine developed to address the increasing demand for precision machining of small components in electrical, medical, and prototyping applications. Conventional CNC machines, though highly accurate, are often unsuitable for such tasks due to their high cost, large size, and excessive energy consumption. In response, this research focuses on developing a compact and affordable alternative within a constrained budget while maintaining acceptable performance standards. An open-frame vertical milling configuration was selected based on a comparative assessment of structural efficiency, material usage, accessibility, and stiffness considerations. The machine frame was fabricated using 6061 aluminium alloy, with critical load-bearing components reinforced using higher-strength aluminium. A three-dimensional model of the machine was developed in SolidWorks, and structural evaluation was conducted using finite element analysis to determine stress distribution, deformation characteristics, and dynamic behaviour. Modal analysis revealed that the vertical support frame, behaving as a cantilever beam, governs the overall dynamic response of the system. The corresponding natural frequency was used to define safe spindle operating conditions and to minimize the risk of resonance during operation. The prototype demonstrates a compact working envelope suitable for small-scale manufacturing, with significantly reduced power consumption compared to conventional systems. Despite achieving satisfactory structural performance, observed machining errors linked to leadscrew deflection indicate areas requiring further refinement. These findings collectively establish that, through careful integration of design simplicity, material selection, and structural analysis, a functional and economically viable mini-CNC milling machine can be developed for small-scale and educational applications.
A et al. (Mon,) studied this question.