Design and Experimental Study of a 4-Axis CNC Laser Engraving Machine

Laser engraving technology is widely adopted in manufacturing due to its high precision, non contact operation, and ability to process a variety of materials. However, most low cost engravers are limited to planar or three axis operations, restricting their use to flat surfaces and simple applications. This study presents the design, fabrication, and experimental evaluation of a low cost 4 axis laser engraving machine capable of multi-surface and cylindrical engraving. The mechanical system features a lightweight modular aluminum frame, a rotary A-axis for circumferential operations, and a compact assembly optimized for small scale use. Finite element analysis (FEA) confirmed the structural stability of the A-axis and frame, with a maximum stress of 6.78 MPa, displacement of 0.087 mm, and strain of 8.84 × 10⁻⁴, all within safe limits for aluminum components. Experimental tests included both planar 3-axis and 4-axis cylindrical engraving, successfully producing uniform lotus and butterfly patterns on cylindrical workpieces with high repeatability and clear line quality. The results demonstrate that the proposed prototype achieves stable, accurate, and cost effective engraving, fulfilling the requirements for educational, research, and small-scale manufacturing applications