You wanted to hear about a case study and I choosed: the impeller.
And I chose right because this was one of the most sensitive, technically demanding reverse engineering projects I’ve done so far.
Some projects challenge your skills.
Others challenge your judgment.
This one did both.
We were handed an industrial impeller that had been in operation for over 30 years, longer than I’ve been alive. The client had no CAD, no drawings, no specs, just the part.
And that part had stories. Erosion, fatigue, uneven wear… and not a single blade matched the next.
The Mission:
Rebuild a parametric, high-fidelity CAD model of the impeller for digital archiving, future manufacturing, and simulation. But there was a catch:
The curvature of the blades directly controls the flow rate and pressure performance. One small deviation? The entire system fails.
This wasn’t just modeling, it was a surgical operation in reverse.
The Workflow:
Scan Acquisition:
- Used high-resolution scanning (The FreeScan Trio) by SHINING 3D
- Multiple scan angles to capture blade geometry and trailing edge erosion
Blade Extraction:
- Manually isolated each blade
- Ran deviation analysis to identify the least-deformed one
- Chose a “golden blade” to rebuild and symmetrically replicate
Modeling:
- Used Geomagic Design X Pro
- Created surface patches, converted to parametric sketches
- Blades were lofted using curvature continuity constraints
- Hub and base reconstructed using axis alignment and rotational patterns
Engineering Judgment in Action:
This wasn’t just about modeling what the scan showed. It was about understanding what the impeller should have been, from a fluid dynamics perspective.
I referenced pump performance tables to validate curvature decisions. The goal: match the intended flow rate and head pressure.
I matched the curvature and blade profile to the 24° design point for optimal performance reconstruction.
Final Deliverables:
- Fully parametric CAD model
- Editable blade angle and profile
- CAM-ready geometry for CNC or casting
- Performance confirmed via engineering tables
Key Takeaways:
- Reverse engineering is not copying – it’s reconstructing intent
- Aging parts tell a story – but the real job is decoding it
- Engineering intuition + precision tools = reliable restoration
- The older the part, the more respect it deserves – both mechanically and historically.
