Reverse Engineering

Reverse engineering is the process by which we will first digitize a physical object through 3D scanning and then convert it to a CAD model or a solid body in the form of a step, iges or parasolid file.

General

For the conversion from scan to CAD, we use specialized reverse engineering software. This is the link between 3D scanning and traditional CAD software (Solidworks, Siemens NX, Catia, etc.).

Over the years, we have built a systematic approach so that you always receive a quality CAD model that is useful for your application, and where you also have a clear picture of the differences between this model and the original scan. Below is an overview of our typical workflow for reverse engineering.

STEP 1: Calibration

Before we can start the actual scanning work, the scanner needs to be calibrated.

The calibration panel is placed in front of the scanner within the specified distance. Meanwhile, proper lighting conditions and setup stability are checked.
Warming up the scanner is necessary to ensure consistent operation.
Once this is done, the calibration routine can be performed.
The calibration is followed by a verification step to check that the scanner is correctly aligned and provides sufficient accuracy.
If necessary, recalibration is performed.

Calibration is necessary to make accurate and reliable measurements, which is obviously essential. This also ensures consistency between scans, allowing for accurate comparisons and analysis of data sets.

STEP 2: 3D Scanning

After calibration, we start digitally capturing the geometry of the physical object using a 3D scanner. This scanner creates a point cloud, a dense collection of data points that represent the surface of the object.

Depending on the part to be scanned, we use our blue light scanner, with or without photogrammetry, or the X-ray CT scanner.

The goal is to obtain an accurate representation of the object’s dimensions, shape and surface features. The result is then a rough point cloud or mesh model.

STEP 3: Data cleaning and processing

The point cloud data collected during scanning often contains noise or errors, such as overlapping points or unwanted artifacts. This step involves cleaning and refining the data to ensure accuracy. In this process, we engage:

Remove unnecessary points or noise.
Closing gaps in scan data.
Optimize the mesh by reducing the number of polygons without losing details.
Align the dataset in the global co-ordinate system.

The result is a high-quality mesh model ready for further processing.

STEP 4: Conversion from Mesh to CAD

The next step is to convert the mesh model into a Computer-Aided Design (CAD) model. This is done using reverse engineering software.

Step by step, we will divide the mesh into its different main shapes in order to model it according to the traditional CAD operations (sketching, extrusion, rotation, boolean…) We try to work as much as possible according to the general design principles (perpendicularity, concentricity…) without deviating too much from the original scan.

When standard prismatic shapes (planes, cylinders…) are not sufficient we start using nurbs surfaces (free-form surfaces) or a combination of both.

The result is a CAD file (E.g. STEP, IGES or parasolid file) suitable for further machining or production.

STEP 5: Validation

Once the CAD model is created, it is compared to the original scan to ensure accuracy. This step validates the reverse-engineered model against the physical object.

A color plot visualizing the difference between the two allows very quick and visual identification of possible discrepancies. Adjustments are then still possible to eliminate discrepancies.

The result is a validated CAD model that faithfully represents the original object.

STEP 6: Analysis & Redesign

If the purpose of reverse engineering is to improve the design or functionality of the object, this step includes using the CAD model for further analysis and redesign. This step is performed again by our client where, for example, consideration can be given to:

Simulations or stress analyses to understand performance.
The design can be customized for better functionality, ergonomics, durability or efficiency.

The result is an optimized design that is ready for prototyping or production. Of course, this new design can again undergo a scanning process to check the dimensions and quality before moving to series production.

STEP 7: Prototyping or Production

The final CAD model is now ready to be used for production. Depending on the application, the file can be used for manufacturing methods such as CNC machining, 3D printing or injection molding.

An appropriate production method is selected, and results in a physical replica or improved version of the original object.