Every scanner has a resolution spec. Ours is 0.2mm. That number gets thrown around in marketing materials without much explanation of what it actually means in practice — what it captures, what it misses, and when scanning is the right approach versus modeling from scratch.
Here’s the practical reality.
What “0.2mm Resolution” Actually Means
Resolution in structured light scanning refers to the minimum distance between measured points on the part’s surface. At 0.2mm resolution, the scanner captures a data point every 0.2mm across the surface — roughly 25 points per square millimeter.
This is not the same as accuracy. Resolution is point density. Accuracy is how close each point’s measured position is to its true position. Our scanner’s volumetric accuracy is ±0.05mm — meaning each measured point is within 50 microns of where it actually is in space.
In practical terms: we capture extremely dense surface data, and that data is dimensionally precise.
Point cloud density: A part with 100 square centimeters of surface area generates roughly 250,000 data points. That’s enough to capture every meaningful feature, curve, and edge on most engineering parts.
What Scanning Captures Well
Complex Curves and Organic Shapes
This is where scanning earns its keep. A part with compound curves, sculpted surfaces, or freeform geometry would take days to measure by hand and hours to model from scratch. Scanning captures the entire surface in minutes.
Examples: intake manifolds, ergonomic handles, legacy automotive body panels, prosthetic interfaces, artisan molds.
As-Built Geometry
Drawings lie. Or rather, drawings show design intent, not what was actually manufactured. Parts that have been machined, cast, or molded often differ from their original drawings due to manufacturing variations, tool wear, or intentional modifications.
Scanning captures the part as it actually exists — including deviations from the original design. This matters when you’re replacing a part in an existing assembly. The replacement needs to fit the real assembly, not the theoretical one.
Wear Patterns
A worn gear, an eroded nozzle, a bearing surface with a wear groove — scanning captures the current state of the part, including its wear. This data helps us understand where the part is stressed, which informs both the replacement design and material selection.
Features Down to 0.3-0.5mm
Embossed text, small fillets, thin ridges, knurling patterns — the scanner resolves features down to about 0.3-0.5mm reliably. Below that, the feature may blend into noise in the point cloud.
Where Scanning Falls Short
No scanning technology captures everything. Understanding the limitations saves time and sets the right expectations.
Deep Internal Features
Structured light scanning requires line-of-sight. If the scanner can’t see a surface, it can’t measure it. Deep holes, internal channels, undercuts, and enclosed cavities are invisible to the scanner.
Workaround: We can scan the part in pieces (if it can be disassembled), use measurement tools for internal features, or combine scanning with CMM probing for critical internal dimensions.
Very Dark or Reflective Surfaces
Black surfaces absorb the projected light. Mirror-finish or chrome surfaces scatter it. Both result in poor data capture.
Workaround: A light dusting of matte scanning spray (chalk-based, temporary, easily removed) makes any surface scannable. We apply this routinely — it adds 5 minutes to the process and washes off with water.
Sub-0.1mm Details
Thread profiles, micro-textures, fine engravings below 0.1mm — these are below the scanner’s practical resolution. We capture the overall geometry and add these features manually in CAD using standard specifications (thread callouts, texture designations).
Transparent or Translucent Parts
Clear plastics, glass, and translucent materials are largely invisible to structured light. The scanning spray workaround helps but may not be desirable on optical components.
Alternative: For transparent parts, we typically measure critical dimensions by hand and model from scratch, using the physical part as a reference rather than scan data.
Scan Output Formats
The scanner produces a mesh — a 3D surface made of triangles.
STL (Standard Triangle Language): The most common mesh format. Compatible with virtually all 3D printing and CAD software. This is our default output.
OBJ: Similar to STL but supports color and texture data. Used when surface appearance matters (archiving, visual models).
STEP (after CAD conversion): The scan mesh is not a STEP file. Converting scan data to a clean STEP file requires manual CAD work — rebuilding the geometry as parametric features with defined dimensions and tolerances. This is a separate deliverable from the scan itself.
Scan vs. Model From Scratch
This is the key decision point: when do you scan, and when do you model from scratch?
Scan When:
- You have an intact physical reference part
- The part has complex or organic geometry that would be time-consuming to model
- You need to match as-built dimensions (not drawing dimensions)
- The geometry is unique or custom (no standard part number to look up)
- You need digital archival of the part’s current state
Model From Scratch When:
- The part is too damaged to scan meaningfully (less than 60-70% of original geometry intact)
- The part is geometrically simple (rectangular housings, basic brackets) — modeling is faster than scanning
- You want to redesign the part, not replicate it
- No physical reference exists (you’re working from drawings, photos, or measurements)
- Internal features dominate the geometry
Do Both When:
- You need the exterior scanned and interior features modeled from measurements
- You want to scan the original part, then modify the CAD model for improved performance
- You’re creating a replacement that needs to match some dimensions exactly and change others
The Scan-to-CAD Gap
This is the most misunderstood part of reverse engineering. A raw scan mesh and a production-ready CAD model are fundamentally different things.
A scan mesh:
- Is geometrically accurate but contains millions of triangles
- Has no dimensional intelligence (no “this hole is 8.00mm ± 0.05mm”)
- Can’t be easily modified (changing a wall thickness means reshaping thousands of triangles)
- Is printable as-is for a visual replica but not for a precision production part
A parametric CAD model (rebuilt from scan data):
- Has defined features: holes, fillets, chamfers, bosses, walls with specific dimensions
- Includes tolerances on mating surfaces
- Can be modified easily (change a dimension, and the geometry updates)
- Is the basis for manufacturing — 3D printing, CNC machining, injection molding
The CAD rebuild is where we add engineering value. We don’t just trace the scan — we interpret it, clean up manufacturing artifacts, add proper tolerances, and deliver a model that’s ready for production.
How to Prepare Parts for Scanning
If you’re sending us a part for scanning:
- Clean it. Remove grease, oil, paint chips, and debris. The scanner captures the surface — contamination becomes geometry.
- Matte surface preferred. If the part is glossy or dark, we’ll apply scanning spray. If you’d prefer we don’t (delicate or coated surfaces), let us know and we’ll discuss alternatives.
- Stable positioning. The part needs to hold still during scanning. We have fixtures and clamps, but if the part has a natural flat face to sit on, that speeds up setup.
- Include mating parts if possible. If the scanned part interfaces with other components, sending those along helps us verify fit during the CAD rebuild phase.
Getting Started
Email us photos of the part and a brief description of what you need:
- Scan only (mesh file for your use)
- Scan + CAD (production-ready STEP file)
- Scan + CAD + printed replacement
We’ll tell you which approach fits your situation and provide a quote within 24 hours. For time-sensitive jobs, scanning typically happens same-day or next-day after receiving the part.