Comparison of 3-axis and 5-axis CNC machining capabilities: Differences in complex surface scenes

In the processing of simple planar parts, the difference between the two is not significant; However, when facing complex surfaces, polyhedra, and irregular structures, the advantage of 5-axis capability increases by an order of magnitude.

1. Processing complexity: 3-axis has blind spots, 5-axis has almost no blind spots

3-axis machining: Due to the limitation of the fixed posture of the cutting tool, it is impossible to machine complex structures such as steep inclined surfaces, inverted curved surfaces, deep cavity inner walls, impeller blades, etc; Forced machining can result in tool interference, deterioration of cutting conditions, and even inability to form at all.

5-axis machining: The cutting tool can adjust the spatial angle arbitrarily, and can machine parts that cannot be machined in 3-axis, such as impellers, blades, complex mold cavities, medical implants, and aerospace irregular structural parts; For features such as deep cavities, narrow slots, and inverted buckles, one can avoid interference from the handle by adjusting the angle, achieving one-time molding.

2. Clamping times and positional accuracy: one clamping vs multiple cumulative errors

This is one of the most core values of 5-axis and a must-have for high-precision complex parts.

3-axis machining: Multi sided and multi curved parts require multiple flips for clamping, resulting in positioning errors each time. Accumulated form and position tolerances can easily exceed the tolerance limit; The positional accuracy, coaxiality, and symmetry of different surfaces are difficult to guarantee, and manual repair is required in the future.

5-axis machining: All machining features can be completed in one clamping, completely eliminating the accumulated errors of multiple clamping, and ensuring the shape and position tolerances and accuracy of the parts; Especially for precision parts with multiple holes and benchmarks, the consistency of accuracy is much higher than that of 3-axis split machining.

3. Surface quality and processing efficiency: There is a significant difference in the quality of curved surface forming

Surface smoothness: During 3-axis machining of curved surfaces, the contact angle between the tool and the surface constantly changes, and the cutting conditions are unstable, which can easily lead to tool marks and step patterns. Subsequently, a large amount of manual polishing and grinding is required; During 5-axis machining, the cutting tool always maintains the optimal cutting posture, with high surface smoothness and almost no obvious cutting marks, greatly reducing post-processing workload.

Processing efficiency: Single clamping eliminates the need for multiple fixture changes and auxiliary time for table alignment; At the same time, the cutting conditions of the tool are better, and higher cutting parameters can be used, resulting in a significant improvement in overall machining efficiency. The more complex the structure, the more obvious the efficiency advantage of 5-axis.

4. Tool life and process stability

When machining large angle curved surfaces with 3-axis machining, the tool is eccentric in cutting, subjected to uneven forces, the cutting edge wears quickly, and the dimensional stability is poor; 5-axis machining tools always maintain the optimal cutting angle, with uniform cutting force, slower tool wear, more stable machining process, and better consistency of batch parts.