Choosing the Right 3D Scanner

The technologies used in 3D scanners are as follows:

Lidar (Light Detection and Ranging)

3D Lidar scanners emit laser pulses to measure the distance between the device and the target object. The sensors then detect the laser reflections to create a 3D point cloud representing the object’s surface.

Laser triangulation

This technology uses a laser beam that reflects off the object to be measured. By measuring the angles between the beam source, the object receiving the incident beam, and the sensor receiving the reflected beam, trigonometric triangulation can be used to calculate distances with great precision.

Time-of-flight (TOF)

TOF scanners send pulses of light toward the object and then measure the time it takes for the light to return to the scanner. This information is used to determine the distance and thus create a 3D image of the object.

Phase-shift

Scanners that use phase-shift technology project light patterns with different phases onto the object. Sensors measure pattern deformation to calculate distance and create a 3D model.

Structured light

Scanners that use structured light technology project light patterns onto the object and capture these distorted patterns to calculate the 3D coordinates of the object’s surface.

3D scanners have many industrial applications:

Metrology and quality control

Thanks to their versatility, 3D scanners for metrology are capable of measuring parts of all sizes, from small electronic parts to large structures such as aircraft and ships. Their use improves measurement accuracy, speeds up quality control processes, and facilitates the development of innovative products in a variety of industries.

The industrial sectors that benefit from 3D scanners for metrology are varied. They are also used in the aerospace industry, where they are used to measure precision components in aircraft manufacture. The automotive industry also takes advantage of this opportunity to control the quality of mass-produced parts.

Manufacturing

3D scanners are also widely used in the manufacture of parts and equipment, where their precision makes it possible to verify the conformity with required specifications.

In laboratories

Research and development laboratories benefit from these scanners for a wide range of applications. They can be used in reverse engineering projects, i.e. to understand the design of an existing product by creating its 3D model from measurements or to simulate the behavior of parts in specific environments.

3D scanner model HP-L-8.9 for measuring arms and reverse engineering from HEXAGON MANUFACTURING INTELLIGENCE on DirectIndustry

Reverse engineering using 3D scanner data and calculations made on REcreate software from HEXAGON MANUFACTURING INTELLIGENCE on DirectIndustry

The purpose of a 3D scanner is to generate a digital model of an object to carry out analyses to detect possible defects, measure dimensions and shapes, and compare product characteristics with manufacturing tolerances.

Scanning is generally performed by holding a scanner in the hand. Some scans are automated using a robotic arm.

A scan requires three main elements:

• A light source (blue, red, or white laser) that illuminates the object with a specific grid known to the scanner (blue light is used to filter out ambient white light).
• One or more cameras that read the grid projected onto the object and how it is deformed by the object’s shape. This distorted image of the grid is used to model the relief of the object in question.
• A computer that collects the data and trigonometrically calculates the distances between the grid points.

Various technologies and methods are available to capture and measure the three-dimensional geometry of an object in industrial applications.

Here are the main steps needed to carry out this process:

1. Capture data from the object to be measured: 3D scanners use data capture methods such as structured light, laser, infrared light, stereophotogrammetry, or computed tomography (CT) to digitize the object’s surface or structure.

2. Create a point cloud: The measured three-dimensional coordinates are combined to create a point cloud. This point cloud represents the external surface of the scanned object and contains millions of points with their XYZ coordinates.

3. Data processing: Once the point cloud has been created, it is necessary to process the data to clean up any errors or imperfections due to reflections, shadows, or interference. Specialized software is used to filter and optimize the point cloud.

4. 3D model creation: Using the point cloud, the 3D scanner creates a complete 3D model of the scanned object. This model can consist of a grid of triangles that forms the surface of the object, or a more detailed volumetric representation, depending on the precision required.

5. Data analysis and use: Once the 3D model has been created, it can be used for quality inspection, reverse engineering, deformation analysis, simulation, computer-aided design (CAD), or 3D printing.

The data collected by 3D scanners is highly accurate and detailed, and therefore offers many advantages:

Improved product quality: 3D scanners can capture data with a high degree of accuracy, enabling reliable and precise measurements of objects and parts. This guarantees better production quality and greater compliance with specifications.

Comprehensive analysis: 3D scanners provide comprehensive data on object geometry, enabling detailed analysis of dimensions, shapes, defects, and other critical product features.

Speed: 3D scanners are capable of digitizing objects in a matter of moments, considerably speeding up quality control, reverse engineering, and design processes.

Improved quality control: 3D scanners make it easier to inspect and verify product compliance with safety and quality standards, ensuring reliable end products that meet requirements.

Cost reduction: By quickly detecting defects on parts before they are used, 3D scanners help avoid costly errors and reduce material waste. This also reduces production cycle times and therefore manufacturing costs.

Optimization of manufacturing processes: The data provided by the scanners can also be used to identify areas of the manufacturing process that could be improved and optimized.

Reverse engineering: 3D scanners are used to create precise 3D models of existing objects, facilitating the reverse engineering process and enabling components to be reproduced or modified with great precision.

Automation: Some measurement and inspection tasks can be automated, reducing reliance on manual measurement methods that are potentially prone to human error.

3D printing: 3D scanners can also be used in combination with 3D printers to create prototypes or customized parts.

Which 3D scanner you choose will depend on several factors. Here are the main criteria to consider when choosing the 3D scanner that best suits your needs:

Precision level: You need to identify the precision you require for your measurements. Some applications require very high precision, while others can make do with less. Opt for a high-precision 3D scanner.

Size and type of objects to be scanned: Determine the size and complexity of the objects you wish to scan. Some scanners are suitable for small, finely structured objects, while others are designed to scan large structures. If you’re working with large parts, choose a suitable 3D scanner.

Scanning speed: Evaluate the speed at which you need to scan your objects. Some scanners are faster than others, which can be crucial in high-speed production environments.

Surface type: Make sure the 3D scanner you choose is suitable for the surfaces you want to measure (reflective, dark, smooth, rough, etc.).

Type of material: Some scanners have difficulty with certain types of material. Make sure the scanner you choose works well with the materials you will be scanning.

Type of scanning technology: There are different types of 3D scanners (structured light scanners, laser scanners, photogrammetric scanners).

Portability: If you’re working on several sites or in hard-to-reach places, you’ll want a 3D scanner that’s portable and easy to carry.

Software: Check that the 3D scanner’s data processing software is compatible with your other CAD and CAM tools, to facilitate workflow. Intuitive, powerful software is essential to fully exploit the 3D scanner’s capabilities.

Price: This can vary considerably from one model to another.