1 · Basics: Axis Definitions
| Term | Definition | Motion Type | Alias |
|---|---|---|---|
| 3-Axis CNC Mill | Tool or table moves in X, Y, Z linear directions | 3-axis simultaneous | VMC (Vertical), HMC (Horizontal) |
| 5-Axis CNC Mill | Adds two rotary axes (A/B/C) to X-Y-Z | 5-axis simultaneous or 3+2 positioning | Swivel-head, Trunnion, Dual-Rotary |
- 3+2 machining: Fixed-position rotary tilting, followed by 3-axis milling
- True 5-axis: All five axes move simultaneously to cut complex surfaces
Tip: To visually demonstrate axis movement on your website, consider embedding an animated GIF or interactive 3D model.
2 · Mechanical Structure Comparison
2.1 3-Axis Machine Types
- VMC (Vertical Machining Center): Compact, efficient chip evacuation, ideal for small to medium production.
- HMC (Horizontal Machining Center): Horizontal spindle with rotary table, great for deep cavities and automation.
2.2 5-Axis Machine Types
- Swivel-Head (B+C): Spindle swivels in multiple directions. Compact layout, suitable for aerospace.
- Trunnion (A+C): Cradle-style rotary table, excellent rigidity, used in molds and impellers.
- Dual-Rotary Table (A+C): Fast multi-face machining for small complex parts.
- Gantry-Type 5-Axis: Gantry frame with swivel head, designed for large molds and composites.
3 · Performance Comparison Table
| Metric | 3-Axis | 5-Axis (3+2) | True 5-Axis |
| Faces Machined in One Setup | ≤ 2 | 5-position | Any complex surface |
| Surface Accuracy | ±0.015 mm | ±0.010 mm | ±0.005 mm |
| Tool Access | Limited | Good | Best |
| Setup Time | ★★★ | ★★ | ★ |
| Programming Difficulty | ★ | ★★ | ★★★★ |
| CAM Requirements | Standard | Requires 5-Axis module | Full 5-Axis software |
| Machine Cost* | ¥300k–800k | ¥600k–1600k | ¥1200k–4000k |
| ROI Period (Example) | 10–14 months | 18–24 months | 24–36 months |
* Based on 800 mm travel models in the China market, Q1 2025 average pricing.
4 · Sample ROI Calculation
Based on actual data from Mold Factory A
| Item | 3-Axis Setup | 5-Axis Setup |
| Equipment Investment | 2 × VMC = ¥1.6M | 1 × 5-Axis = ¥2.6M |
| CAM + Training | ¥50k/year | ¥150k/year |
| Fixtures & Tools | ¥200k | ¥350k (including centering jigs) |
| Annual Output | ¥5M | ¥8.5M |
| Gross Margin | 25% | 33% |
| Payback Period | 14 months | 26 months |
Conclusion: While 5-axis machines cost more upfront, their increased efficiency and margin potential result in higher profits starting from year 2.
5 · Industry Applications
✈️ Aerospace
Blades, turbine discs, and structural parts in a single setup for better strength.
🚗 Automotive & New Energy
Pump bodies, crankshafts, housings – processed with fewer jigs.
🛠️ Precision Molds
Large curved electrodes and mirror-finished injection molds with fewer electrodes.
6 · Upgrade Decision Workflow
- Analyze Part Complexity: If over 30% of past orders require 4+ faces, consider evaluating 5-axis.
- Diagnose Bottlenecks: Are multi-clamp setups causing scrap or rework?
- Assess Cost vs Benefit: Use the ROI model above to estimate NPV.
- Choose a Pilot Model: Start with a 500–650 mm 5-axis to supplement existing 3-axis capacity.
- Upgrade Processes: Create CAM templates, tool libraries, and probing standards.
7 · Implementation Tips
- Software: Invest in CAM software with customizable post-processors (NX, PowerMill, etc.)
- Machine Configuration: Include probing systems, mist collection, 40+ tool magazine, torque-compensated spindles
- Quality Control: Use Renishaw or Marposs probes, plus CMM for validation
- Tooling Strategy: Use coated ball-end mills, long-edge cutters, unified collets for less runout
- Trial Run: Conduct test cuts with CMM verification. Move to mass production after PPAP approval
8 · Final Thoughts
- 3-axis CNC mills are still very cost-effective for most 2.5D part production
- 5-axis CNC mills unlock higher-margin markets and enable faster lead times
- Yucheng offers complete CNC mill solutions – including 3-axis & 5-axis machines, jigs, tools, software, and training
