Difference between 3-axis CNC machining and 5-axis CNC machining

1. 3-axis CNC machining: Three directional linear feed, fixed posture cutting

A 3-axis machining center is the basic form of CNC machining, with three linear motion axes of X, Y, and Z. The tool always maintains a fixed posture perpendicular to the worktable, and cutting is achieved through the movement of the worktable plane and the up and down feed of the tool.

Movement mode: The workpiece is fixed on the worktable and only moves in the X/Y plane. The tool is fed up and down along the Z-axis, and the orientation of the tool tip remains unchanged throughout the entire process;

Processing scope: Only the top and simple side surfaces of the parts can be processed, and complex inclination angles, inverted curved surfaces, and polyhedral features cannot be clamped in one go;

Advantage scenarios: 2.5D and shallow surface parts such as flat surfaces, cavities, grooves, and simple contours are the main machining solutions for the vast majority of conventional structural components.

For complex curved parts, 3-axis machining can only process different surfaces step by step by flipping and changing fixtures multiple times, which is not only inefficient but also introduces positioning errors caused by multiple clamping.

2. 5-axis CNC machining: multi axis linkage, tool posture changes according to the shape

On the basis of the X, Y, and Z linear axes, a 5-axis machining center adds two rotation axes (usually two of the A/B/C axes), which can achieve real-time changes in the relative spatial posture between the tool and the workpiece, and the tool tip point is always fed along the normal direction of the surface.

According to the structural form, it can be mainly divided into three categories:

Dual turntable structure: The workpiece swings in conjunction with two rotating tables, suitable for small and medium-sized precision parts;

Swing head+turntable structure: tool swing+workpiece rotation, strong universality, considering both large and small parts;

Double swing head structure: The tool swings at both ends and the workpiece is fixed, suitable for large and heavy workpieces.

The core advantage lies in the five axis linkage: during the machining process, the tool posture is adjusted in real-time with the surface, ensuring optimal contact between the blade and the surface while avoiding interference, and completing the machining of all surfaces of the part in one clamping.