How SEAM Reconstructed a High-Precision Mould Insert Using CT Scanning and CMM Inspection

Injection moulding relies on precision-engineered mould inserts that deliver accuracy, repeatability, and long service life. When these inserts become worn—or when original drawings are unavailable—manufacturers face significant challenges in maintaining product quality and production efficiency.
This case study outlines how SEAM combined industrial Computed Tomography (CT) scanning with Coordinate Measuring Machine (CMM) metrology to reverse engineer a worn mould insert, recreate its digital geometry, and assess the extent of material degradation.

Client Challenge

A manufacturer required an accurate reproduction of a worn injection mould insert but no longer had access to the original design drawings. The primary objectives were to:

• Recover internal and external features with high dimensional accuracy

• Evaluate wear and deformation across critical surfaces

• Characterise the material and surface treatment

• Produce a validated CAD model suitable for re-manufacturing

• Identify potential opportunities for design improvement

Traditional methods alone were insufficient—particularly for internal channels and hidden geometries—so SEAM implemented a hybrid CT–CMM methodology to ensure full coverage and high precision.

CT Scanning for Internal and External Geometries

The first stage involved scanning the insert using SEAM’s industrial CT system.
This non-destructive technique captured a complete volumetric dataset, including:

• Internal cooling channels

• Ejector pin housings

• Undercuts and enclosed cavities

• Small radii, chamfers, and hidden features

The scan achieved a voxel resolution of 10–20 microns, allowing fine geometric details to be resolved. CT provided the comprehensive view needed for accurate reverse engineering—something that would be extremely difficult or impossible using external metrology alone.

CMM Inspection of High-Precision Functional Surfaces

While CT captured full geometry, external functional features—such as parting surfaces, mating interfaces, and shut-off regions—required high-accuracy tactile measurement using SEAM’s CMM system.

The CMM was used to measure:

• Parting planes and critical sealing surfaces

• Locating features and alignment datums

• High-tolerance contact faces

• External profiles subject to tight dimensional requirements

Integrating both datasets ensured the final CAD reconstruction was both complete and dimensionally reliable.

Hybrid Dataset Alignment & CAD Reconstruction

The CT-derived polygonal mesh was reconstructed and then aligned with the high-precision CMM dataset. This hybrid dataset formed the foundation for a new parametric CAD model.

This stage included:

• Cleaning and smoothing the CT mesh

• Aligning functional datums to CMM measurements

• Rebuilding nominal geometry where wear was evident

• Reconstructing internal channels to exact tolerances

• Restoring deformed regions to original design intent

The result was a fully engineered digital twin of the mould insert.

Outcome & Recommendations

SEAM successfully delivered a validated digital twin of the mould insert, enabling:

• Accurate reproduction of the tool

• Identification of geometric wear and root-cause contributors

• Improvement proposals for channel design, surface treatments, and tolerance adjustment

• Reliable digital documentation for future maintenance and manufacturing

Conclusion: The Advantages of a CT–CMM Hybrid Approach

This project demonstrates how combining CT scanning with CMM inspection provides a powerful solution for reverse engineering complex tooling. CT offers a complete, non-destructive view of internal geometry, while CMM ensures accuracy for critical functional surfaces. Together, they produce a high-fidelity, production-ready digital model that not only enables replication but also supports design enhancement and extended mould life.

If your organisation requires precision reverse engineering, tooling assessment, or high-accuracy dimensional validation, SEAM’s metrology team can support projects from micrometre-scale analysis to full component reconstruction.

👉 Contact SEAM to discuss your next reverse engineering or metrology challenge