Complex 5-Axis Titanium Structural Bracket — Single-Setup Consolidation
Eliminating 6 of 7 setups on a complex aerospace structural bracket through 5-axis consolidation, tombstone fixturing, and in-process probing, reducing cycle time by 60%.
Case Facts
| Application | Aerospace structural bracket |
|---|---|
| Material | Ti-6Al-4V (Grade 5) |
| Processes | 5-axis-machining, cnc-machining, milling |
| Equipment | Mazak i700 5-Axis, Mazak Integrex i-200 |
| Surface Finish | Ra 0.4 µm |
| Standards | AS9100D, NADCAP, ISO 2768-f |
| Quantity | 1,200 units/year |
| Tolerance | ±0.05 mm |
| Lead Time | 5-6 weeks |
Challenge
A complex aerospace structural bracket with 27 features on 6 faces required seven separate setups on 3-axis machines, resulting in 12.5 hours cycle time per part. Stack-up tolerances from multiple setups caused 18% rejection rate due to feature-to-feature misalignment exceeding ±0.10 mm. Inspection required 2 hours per part on CMM.
Solution
Consolidated to a single 5-axis setup on a Mazak i700 using engineered tombstone fixturing with datums referencing all 6 faces. Developed custom CAM strategy: (1) Rough all features in single program using dynamic milling; (2) Semi-finish with 0.3mm stock remaining; (3) Full 5-axis simultaneous finishing with 0.1mm radial engagement. Implemented in-process probing for automatic datum shift compensation. Added RFID tracking for tool life management across the production run.
Result
Cycle time reduced from 12.5h to 5.0h (60% reduction). Setup count: 7 → 1. Rejection rate dropped from 18% to 1.2%. Inspection time reduced from 2h to 25 minutes (in-process probing). Feature-to-feature misalignment consistently below ±0.03 mm. Annual cost savings of $187,000. NADCAP certification maintained throughout.
Key Metrics
| Metric | Before | After |
|---|---|---|
| Cycle Time | 12.5 h | 5.0 h |
| Rejection Rate | 18% | 1.2% |
| Setups Required | 7 | 1 |
| Inspection Time | 2 h | 25 min |
| Annual Savings | - | $187,000 |
Lessons Learned
- Complex titanium brackets with features on 6 faces benefit enormously from 5-axis consolidation into a single setup
- Engineered tombstone fixturing with 6-face datum referencing eliminates stack-up tolerance accumulation
- In-process probing with automatic datum compensation is essential for holding ±0.05 mm across complex geometries
- RFID tool life management prevents unplanned tool changes during long 5-hour continuous machining cycles