A mesh is not a model. Turning scan data into parametric CAD is where the value is — and where most reverse engineering projects stop too early.
Plenty of suppliers will scan a part and hand back an STL. That file will print, and it will visualise, but it cannot be revised, toleranced or manufactured from. The engineering work starts after the scan.
Decide what the part means before you model it
A worn casting scanned at 40 microns records the wear, the draft, the shrink and the damage as equal facts. Rebuilding it faithfully reproduces all four. The job is to recover design intent: which surfaces are functional, which radii were tooling artefacts, and what the nominal dimensions were before twenty years of service.
- .01Functional surfaces — rebuild as exact geometry, not fitted mesh
- .02Fastener positions — measure the pattern, then regularise it
- .03Draft and radii — infer the original tooling, do not trace the wear
- .04Nominal sizes — round to sensible stock and standard fits
- .05Damage and corrosion — explicitly excluded, and noted on the drawing
Two deliverables, not one
A reverse engineering job should return a parametric native model plus an as-built drawing pack showing what was measured and what was inferred. The second document is what protects you when the new part does not fit the old assembly.
SCANNING IS MEASUREMENT. MODELLING IS ENGINEERING. THE INVOICE SHOULD REFLECT BOTH.
Verify against the original
The finished model should be compared back to the point cloud with a deviation map, and the tolerances on the new drawing set from that comparison — not guessed. Anything outside the expected envelope gets explained before issue.