The Challenge
A precision aerospace machining company in Bengaluru — a Tier 2 supplier to HAL, ISRO, and private aerospace integrators — produces complex profiled components including turbine shroud brackets, fuel system fittings, and aluminium structural sub-assemblies. These components carry stringent GD&T callouts: true position ±5 µm, profile tolerances of 0.008 mm, angularity to 10 arc-seconds, and full audit trails at every inspection stage.
Their sole inspection method was a CMM housed in a dedicated air-conditioned lab requiring a 4-hour thermal soak per batch. A 25-feature component inspection took 35–45 minutes. With monthly throughput of 600–800 machined components, the CMM became a critical production constraint — often running 24 hours a day, leaving no time for First Article Inspection (FAI) programmes.
Key Pain Points
- CMM lab bottleneck — 4-hour thermal soak, 35–45 min per part
- No shop-floor inspection capability near machining centres
- CMM probe crashes causing 2-day downtime per incident
- Backlog of 80–120 components waiting inspection at shift end
- Audit trail generated manually — time-consuming and error-prone
The Solution
Optomech installed the VPP-CNC 4030 Video Profile Projector — a fully motorised CNC measuring system with 400 × 300 mm stage travel, telecentric zoom optics (0.7× to 4.5×), and a 3D touch probe for side-surface features. The unit was positioned on a vibration-isolation table adjacent to a 5-axis machining centre.
The Optomech applications team programmed 10 CNC part programs in Learn Mode over four days — each measuring 18–32 GD&T features and generating a dimensioned PDF report with CAD overlay in under 9 minutes. AutoCAD DXF import aligns each program directly against the design drawing. Operators need zero metrology training to run CNC programs — they simply load the component, select the program, and press Run.
The VPP-CNC was cross-validated against the CMM for 5 critical components. Results aligned to within ±1.2 µm across all measurements — confirming full CMM-equivalent accuracy on the shop floor.
Results Achieved
| Metric | Result |
|---|---|
| CMM inspection time | 35–45 min per component → 8–9 min on VPP-CNC (75% reduction) |
| GD&T accuracy | ±2 µm achieved and confirmed against CMM cross-validation |
| Components per shift | Capacity increased from 18 to 72 per shift |
| CMM dependency | Routine 2D inspection fully removed from CMM — CMM reserved for FAI only |
| Part programs | 10 CNC programs covering 90% of active component drawings — loaded in 4 days |
| Touch probe | 5 components with 3D side-surface features inspected in-line |
| Audit trail | PDF report + CAD overlay auto-generated at end of each inspection run |
| Operator dependency | Reduced — CNC mode requires no metrology training to operate |
"We were completely dependent on our CMM lab. A single probe crash meant two days off the line. The VPP-CNC changed that entirely. It lives on the shop floor, the operators run it themselves, and the reports it produces are good enough for our NADCAP audit package. The Optomech team was excellent — they programmed 10 parts in four days."— Quality Assurance Director, Precision Aerospace Machining Firm, Bengaluru
Have a similar aerospace inspection challenge?
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