Frequently Asked Questions

We can provide scanned data as-is in an STL format.

Models that are reverse engineered can be provided in a STEP, IGES, or Parasolid format. In some cases, we can also provide files in a native SolidWorks format. However, this is determined on a case-by-case basis.

Dimensional accuracy depends on the method used to capture the data. Each measurement tool has its own accuracy.

Generally speaking, our CMM’s provide data that is accurate to ± 15 µm.

Our structured light scanner provides an accuracy of ± 16 µm for parts up to 300 mm.
For parts that are 300 - 900 mm, our structured light accuracy is ± 37 µm.

For items CT scanned in our Zeiss Metrotom 800, our accuracy is ± 9.7 µm.
For items CT scanned in our Zeiss Metrotom 1500, our accuracy is ± 11 µm.

For items that are reverse-engineered and modeled using our scan data as a template, the results can be somewhat variable depending on the material of the original part and the condition of the original surfaces that we are interpolating.

Typically, models that are created from steel parts usually have a surface accuracy of ± .001” or less to the original scanned surface.

The accuracy of models that are produced from plastic injection molding usually has a surface accuracy of ± .001” to .005”. For large parts like auto body panels or bumpers, the surface deviation of the final model may be much larger, depending on part condition and customer needs.

Yes. We have the ability to provide accurate external geometry for items like these.

Yes. However, it is easiest to provide scan data on these types of objects if they can be brought in or sent to our laboratory.

Our ability to blue light scan on location is somewhat limited due to our current restriction of scanning objects up to a maximum of 4 feet.

Yes, we can provide CAD drawings in a 2D DXF format.

We can usually quote most items from detailed photographs that have a size reference with them.

For specialized parts like manifolds or assemblies, we may require that the parts be sent to us for evaluation prior to quoting the project.

3D files or drawings are also helpful if they are available. The more information, the better.

An STL file is already sufficient to 3D print parts. If the customer requires a custom CAD model be produced from parts that have already been scanned by a 3rd party, we have the ability to do so. However, we cannot guarantee the accuracy of the original scan method.

Industrial 3D scanning is a non-contact measurement process that captures the geometry of a physical part and converts it into highly detailed digital data. Technologies such as blue light scanning and laser scanning create millions of measurement points across a surface to evaluate dimensions, form, and manufacturing accuracy.

Models that are reverse engineered can be provided in a STEP, IGES, or Parasolid format. In some cases, we can also provide files in a native SolidWorks format. However, this is determined on a case-by-case basis.

3D scanning can be used on a wide range of components, including:

● Injection molded plastics
● Castings
● Aerospace and turbine components
● Medical devices
● Automotive parts
● Additively manufactured components
● Consumer products
● Rubber and elastomer parts
● Tooling and fixtures

Both simple and highly complex geometries can be scanned.

Accuracy depends on the scanner, part size, material, and inspection requirements. Metrology-grade systems can achieve extremely high precision suitable for dimensional inspection, GD&T analysis, and quality verification.

At Nel PreTech, scanning workflows are designed to support demanding industrial and manufacturing applications where repeatability and measurement confidence matter.

A Coordinate Measuring Machine (CMM) collects discrete measurement points using a touch probe, while 3D scanning captures millions of data points across an entire surface.

3D scanning is often beneficial for:

● Complex freeform geometry
● Organic surfaces
● Rapid inspection workflows
● Full-surface deviation analysis
● Large data collection requirements

CMM inspection and 3D scanning are frequently complementary technologies rather than direct replacements.

Industrial 3D scanning is widely used in:

● Aerospace
● Automotive
● Medical device manufacturing
● Defense
● Consumer products
● Energy and power generation
● Plastics and injection molding
● Additive manufacturing

Manufacturers use scanning to improve quality, validate tooling, reduce scrap, and accelerate product development.

Yes. Depending on the application, 3D scanning can help identify:

● Warpage
● Flash
● Sink
● Surface deformation
● Assembly fit issues
● Wear patterns
● Dimensional nonconformance
● Tool wear or damage

When paired with advanced inspection software, scan data can reveal deviations that may be difficult to identify using traditional measurement methods alone.

Scan times vary depending on part size, complexity, accuracy requirements, and inspection scope. Some scans can be completed in minutes, while larger or more detailed inspection projects may require additional setup and analysis time.

Modern optical scanning systems are significantly faster than many traditional point-by-point inspection methods.

Yes, although highly reflective, transparent, or very dark surfaces can present challenges for optical systems. In some cases, a removable scanning spray or surface preparation may be used to improve data capture quality.

Experienced scanning technicians select the appropriate workflow based on the material and inspection objectives.

A color deviation map visually compares a scanned part against CAD data or nominal geometry. Different colors indicate where the material is above or below tolerance, making dimensional variation easy to interpret.

These reports are commonly used for quality control, tooling validation, and first article inspection.

Yes. 3D scanning is commonly used to support first article inspection by rapidly collecting dimensional data across an entire part surface.

This approach can help manufacturers:

● Accelerate inspection timelines
● Validate tooling and production processes
● Document dimensional compliance
● Identify trends early in production

Yes. Optical 3D scanning is a non-contact technology, making it suitable for delicate, soft, or flexible components that could deform under traditional touch-probe measurement methods.

3D scanning systems can inspect components ranging from very small precision parts to large assemblies.

ZEISS METROTOM 1500 (225KV) CT SCANNER
Maximum Part Size:
Cylindrical volume up to
615 mm & max height 800 mm
OR
up to 330 mm diameter x 870 mm tall
Area of interest resolution:
7 microns
 
 
ZEISS METROTOM 800 (130 KV) CT SCANNER
Max part size:
Cylindrical volume
up to 275 mm &
max height 360 mm
Area of interest resolution:
3.5 microns
 
ATOS Q BLUE LIGHT, OPTICAL NON-CONTACT SCANNER
Measuring area: [mm²]
100 × 70 – 500 × 370

Yes. Accurate dimensional data can help manufacturers:

● Reduce scrap and rework
● Identify process variation earlier
● Improve tooling validation
● Shorten inspection cycles
● Improve assembly fit and function
● Reduce downstream quality issues

Faster access to measurement data often leads to more informed manufacturing decisions.

Blue light scanning is an optical measurement technology that projects structured blue light patterns onto a part surface to capture highly detailed geometry.

Blue light systems are commonly used for:

● Precision dimensional inspection
● GD&T analysis
● Tool and mold validation
● Surface comparison
● Complex geometry measurement

Not entirely. 3D scanning is a powerful inspection technology, but the best inspection strategy often combines multiple metrology methods, including CMM inspection, CT scanning, optical measurement, and traditional gauges.

The right approach depends on the application, tolerance requirements, geometry, and manufacturing goals.

Outsourcing provides access to:

● Metrology-grade equipment
● Experienced inspection professionals
● Advanced analysis software
● Faster project turnaround
● Scalable inspection capacity
● High-end measurement capabilities without capital equipment investment

Many companies outsource scanning to support overflow inspection work, specialized projects, or applications requiring advanced expertise.

One week or less for a typical scan to provide STL files.  Additional services (colormap comparison, first article inspection, porosity analysis, etc) can add additional time.  An expediting option, if possible, can be added to the quote on request.

CT scanning is quoted per scan.  Multiple samples can sometimes fit into the same scan depending on part dimensions, feature sizes, and blueprint tolerances.  Bluelight scanning is quoted per piece.  A minimum order is a single CT scan or a single part for bluelight scanning.  Prices vary for each.

Samples can be shipped or dropped off at our location in Tinley Park, IL.

Yes, we have an FFL license to handle serialized firearm components.

Yes, we can give a scheduled tour with a demo of our services.  We can tailor the tour to the type of parts that you are planning to provide for scanning.

Not exactly. We can only fit a max weight of 55kg onto the stage. Then comes the issue of width. What we could do is complete the pallet in stages.

Yes, our procedure is to CT scan the samples and program the measurement of ISO 80369 dimensions on the scan data.  A report is provided with nominal and tolerance information that contains actual measurements showing within or out of specification.

Yes, this would be a wall thickness analysis. We would look for deviations from the norm and investigate areas of lesser thickness.

No

Yes, this is similar to a normal CT scan.  Scan data is provided with Volume Graphics viewing software that can be used to search for internal defects.

Yes, as always, there are limitations based on part density and path lengths.

Yes, but it depends on the size of the pore, crack, or void and on the size of the sample. This affects the scanning resolution

Yes, it can, as long as the part, fluid, gas mixture has a density difference of 10-15%.

Completing measurements on multi-material parts is possible, and actually having more of the low-density material helps in the scanning process.

Yes, that is one of the greatest benefits of CT. It is almost always non-destructive. The only cases are when the area of interest requires an extremely high resolution or the object does not fit into the machine due to its height.

Without a doubt. This is one of our most common analysis types, called colormaps (or heatmaps), where we can compare an object to a CAD model or to other samples.

Certainly, there are limits to the amount of high-density material we can scan, but porosity and inclusion analysis on additive manufacturing is something we are quite versed in.

 ~30” tall x 24” wide or ~800mm by 615mm

The smallest feature size range we can reliably detect between our 2 machines is 15-21µm. Which is 3x our smallest voxel size

There is a small risk when scanning memory devices because CT scanners use ionizing X-ray radiation. The level of risk increases with longer scan times and higher X-ray power settings. However, studies have shown that the exposure required to cause significant, unrecoverable damage is substantially greater than the scan durations and settings typically used by NPC.

In most cases, this can be answered by the customer simply reading the Cover Sheet or reviewing the bubbled print.  We label all multiple locations either on the print or screenshots on the Cover Sheet.  If they need detailed locations, such as specific heights or exact locations, then we will usually set up a Teams meeting and review the actual measurement program with them so they can see precise locations.

Measurement uncertainty isn’t a fixed number you can apply across the board. These uncertainty values can vary under different conditions, such as the size of the part, its shape, what it’s made of, and the feature you’re checking.  All calculated measurement uncertainties for every piece of equipment in our lab will be included on the Cover Page of your inspection report.

That way, the results can be trusted—they’re traceable, solid, and actually make sense for the tolerances you care about.

No. Our scanned files are exported as STL file formats. To produce a STEP file, further engineering of the data would be required. Once the part is scanned and an STL file is created, it can be imported into our specialized reverse engineering software, where a CAD model can be produced using the STL as a template. Two main workflows can be utilized during this stage - these methods are known as NURBS modeling or parametric modeling (depending on the needs of the customer). The NURBS workflow is a semi-automated process that produces a model of the part in an as-is condition. The surfaces consist of non-uniform patches, and there is no history-based design tree. However, the surfaces are highly accurate. If a parametric model is required, this can be achieved through the parametric modeling process. This produces a model that has perfect geometry (planes, cones, revolves, etc.) with imperfections from the scan data removed. This model can be exported in a STEP format, or a native SolidWorks model with an intact feature tree can be produced.

No. We report measurement results exactly as we capture them—nothing gets changed to make them look compliant.

When a dimension falls outside the allowed tolerance, we document that right in the inspection report. You’ll see the supporting data and, when necessary, visuals for reference. Our job in inspection is to report the facts, keep everything traceable, and not fudge the numbers just to fit the spec.

But here's the good news. Out-of-tolerance findings can be useful. Detailed measurement data backs up root cause analysis, helps validate processes, and guides changes in design or manufacturing; it’s highly actionable data for future parts.

Your expected completion date is listed on your quote. Many projects are finished on or before that date, depending on scope and workload.

If you need a more precise status or timeline update, contact your Nel PreTech representative or call 708-429-4887 to speak with our Operations Manager.

The answer lies in the definition and intent of a “BASIC” dimension within ASME Y14.5.

BASIC dimensions are theoretically exact values used to define the nominal geometry of a part. They are not independently toleranced features and, therefore, are not measured or reported as pass/fail characteristics. Instead, they function as mathematical references—used alone or in combination—to establish the location, orientation, or form of features controlled by GD&T.

Geometric tolerances (such as position, profile, or orientation) apply allowable variation to that nominal geometry. These tolerances define the actual acceptance criteria, often through tolerance zones that differ significantly from traditional linear ± dimensions.

Because of this, treating a BASIC dimension as a standalone, toleranced measurement would undermine the clarity and intent of GD&T. In practice, any data derived from BASIC dimensions is evaluated and reported within the context of the associated geometric control. This is where compliance is determined and where meaningful inspection results are provided.

When you ask for CT data, you can receive several deliverables. The most common being the raw CT data reconstructed and presented using the Volume Graphics Viewer software, myVGL (in a read-only format). Upon request, we can provide the raw 2D images, but this needs to be known before scanning. If you wish, we can also provide the exported data from our scanner so you may perform your own analysis. Your quotes also include the STL files.

Yes, all of this is possible.  This is not specific to CT and can also be accomplished with Blue Light or CMM scanning.  CT, Blue Light, and CMM scanning are what capture the measurement data; what we do with the data afterward is what differs.  We can use that measurement data in design software like SolidWorks or Geomagic Design X to generate a 3D CAD model, or we could bring that same data into measurement software like Volume Graphics or Zeiss Inspect to generate an inspection report or color maps against the CAD model for a deviation analysis.

Electronics reverse engineering is not currently possible. While we can trace the traces using CT data, most markings on board components are printed rather than etched. Meaning we won’t be able to identify any specific component values. You would end up with a map drawn with no labels for cities, roads, or borders. Location accuracy wouldn’t be the issue.

Yes.  By default, all surface finish measurements are reported as micrometers (µm) or microinches (µin).

Common Ra Values (Roughness Chart)

● 0.05 – 0.1 µm: Extremely smooth (mirror finish/lapping).
● 0.4 – 0.8 µm: Smooth (precision CNC turning/milling).
● 1.6 – 3.2 µm: Standard machine finish (general machining).

Yes.  The material or manufacturing process of the part does not typically limit the measurement.  For a CMM, part size is usually the limiting factor.  The smallest CMM tip we have available is 0.2mm Ø.  So, any feature smaller than 0.2mm we would not be able to physically access.

No, but CT scanning can be used depending on part size, geometry, and inspection requirements.

We are solely an inspection laboratory and do not provide calibration reports.  As an inspection laboratory, we issue Inspection Reports but not Certificates of Conformance.  That is usually something a manufacturer will issue, using an Inspection Report as part of that decision.  Our Inspection laboratory follows the ISO 17025:2017 standard, which includes a section on Statements of Conformity.  See below.

a) to which results the statement of conformity applies;

b) which specifications, standards, or parts thereof are met or not met;

c) the decision rule applied (unless it is inherent in the requested specification or standard).

NOTE: For further information, see ISO/IEC Guide 98-4.

The Cover Page on all our Inspection Reports indicates that we use the Simple Acceptance rule and the measurement uncertainty of all the equipment in our lab.  This satisfies the requirements of Section 7.8.6 as it pertains to the ISO 17025 standard.  All of this usually applies to measurement data when compared to a tolerance to determine if it's in or out of spec.