This study evaluates the mechanical performance of a composite beam designed for a hybrid CNC cutting system equipped with both laser and plasma heads. A parametric 3D CAD model was developed in Siemens NX 1899 and analysed using Simcenter 3D Structure 2020.1 with Simcenter Nastran. Static simulations were conducted. Six design variants were tested, varying in shell thickness (2.4–7.2 mm), beam width (170–200 mm), and reinforcement configuration (none, vertical, cross). The preferred configuration variant (Test 6: 4.8 mm shell, 200 mm width, cross stiffeners) achieved a maximum Z-axis displacement of 0.0209 mm and an average displacement of 0.0298 mm at a mass of 22.45, thereby satisfying the adopted stiffness and mass criteria. These findings suggest the suitability of composite as a structural material in hybrid CNC systems, offering enhanced precision, energy efficiency, and operational reliability.