3D scanning services for inspection and reverse engineering

Industrial 3D scanning measures surface geometry without touching the part. A scanner projects laser lines or light patterns, cameras record how they fall on the surface, and software turns that into a dense point cloud and then a mesh. The result is a full digital copy of the outside of the part. It does not show internal features you cannot see, such as hidden channels or porosity; for those, industrial CT scanning measures outside and inside in one pass.

• Handheld laser scanners: fast and portable, good for medium and large parts and on site work
• Structured light (blue or white light) scanners: high point density on small and medium parts, common for castings and molded parts
• Laser trackers and long range scanners: large assemblies, tooling, frames and plant equipment
• CT based metrology: when internal geometry matters as much as the outside

A coordinate measuring machine (CMM) touches discrete points with a probe and is still the reference for tight tolerance features such as bore positions, datums and GD&T callouts on machined parts. A scanner captures the whole surface, which makes it the better tool for freeform shapes, castings, forgings, sheet metal, worn parts and anything where you want to see where the part deviates, not only whether a few points pass. Many shops combine both: CMM for the critical features and a scan for the overall form.

• Form deviation against CAD, shown as a color map across the whole surface
• Warpage, twist and springback on castings, moldings and sheet metal
• Wall and flange positions, hole locations and profile tolerances to the scanner's capability
• Wear, erosion and damage on used parts and tooling
• Missing or extra material compared with the nominal model

What it does not show

• Internal porosity, cracks or inclusions, which need radiographic testing or CT
• Hidden internal channels unless they are open and reachable by the light
• Surface roughness at fine levels, which needs a profilometer
• Reliable data on very shiny, transparent or deep black surfaces without preparation such as a thin scanning spray

When a part has no drawing, a supplier has gone away or a legacy machine needs a spare, the shop scans the part, cleans the mesh and rebuilds it as a parametric CAD model with design intent: true planes, cylinders and fillets instead of a lumpy surface copy. Ask whether you get a mesh only (STL), a surface model or a fully parametric, editable model in your CAD format such as STEP or native files, because the work and the price differ a lot. Worn parts need judgment about what the original nominal was, so say if you can supply a less worn part or known dimensions.

There is no single number. Accuracy depends on the scanner, the size of the part, the setup and the environment. Good structured light systems on small parts reach a few hundredths of a millimeter, roughly 0.001 to 0.002 in, while handheld scanners on large parts commonly sit near 0.05 mm plus a size dependent term, and long range scanning of plant equipment works at the millimeter level. Ask the shop for the stated accuracy of the specific scanner, how it is verified (for example against a calibrated artifact under ISO 10360 style checks) and whether the measurement uncertainty is small enough for your tolerance. A common rule is that the measuring system should be several times better than the tolerance it checks.

1. You send the part description, CAD model if any, tolerances and what decision the result supports.
2. The shop picks scanner and fixturing, and agrees the alignment method (best fit or datum based).
3. Parts are scanned in the lab or on site, with targets or spray where the surface needs it.
4. Data is aligned to CAD or rebuilt into a model.
5. You receive the report, the mesh and any model files.

Deliverables to ask for

For inspection, ask for a color map deviation report with the alignment method stated, tolerance bands that match your drawing, cross sections at critical locations and a pass or fail summary per feature. For first article inspection, ask whether the report can follow your FAI format, such as AS9102 forms in aerospace. Raw files usually come as STL or PLY meshes and point clouds, models as STEP.

Price depends on part size and complexity, surface finish, number of parts, whether CAD comparison or full reverse engineering is needed, on site travel and the report depth.