3+2 positional machining and 5-axis simultaneous machining are suited to different applications;
5-axis simultaneous machining is ideal for complex curved surfaces, whereas 3+2 positional machining is better suited for planar surfaces.
Advantages of 3+2 positional machining:
1) Allows the use of shorter, more rigid cutting tools.
2) The tool can be oriented at an angle to the surface, allowing the spindle head to extend lower and closer to the workpiece.
3) Shorter tool travel distances and reduced program code.
Limitations of 3+2 positional machining:
3+2 positional machining typically involves setting a fixed spindle angle. Complex workpieces may require numerous tilted views to cover the entire part; this can lead to overlapping toolpaths, thereby increasing machining time.
Advantages of 5-axis simultaneous machining:
1) Eliminates the need for special fixtures during machining, reducing fixture costs and avoiding multiple setups, which improves mold machining accuracy.
2) Reduces the total number of fixtures required.
3) Eliminates the need for many specialized tools, thereby lowering tooling costs.
4) Increases the effective cutting edge length during machining, reduces cutting forces, extends tool life, and lowers costs.
Limitations of 5-axis simultaneous machining:
1) Spindle rigidity is generally lower compared to 3+2 positional machining.
2) Certain situations are unsuitable for 5-axis machining-such as when tools are too short or tool holders are too large-making it impossible to avoid vibration at any tilt angle.
3) Machining accuracy errors are greater compared to 3-axis machine tools.
