By: Arno Touré
What if there was a simple and effective way to digitally recreate any object of your daily life?
It was science fiction only a few years ago, but it is now common in many industries around the world.
3D scanners are one of the most important technological innovations of the century, providing real solutions to recurring problems of reverse engineering, logistics, and quality check. Already a powerful visualization tool, it becomes the ultimate creation process if combined with additive manufacturing technologies. But how does all this magic work?
1. 3D Laser Scanning (trigonometric triangulation)
“Laser scanning works quite similar to traditional survey instruments in that it is measuring a horizontal and vertical angle combined with a slope distance, but what it is doing is revolving a laser very rapidly through a vertical and horizontal arc while using those laser pulses to measure the distance” explains Adam Westfall, survey manager at Dewberry.
All this results in a ±2 mm accurate image stored in a CAD file, ready to be 3D printed.
In most of the cases, a single day is needed to perform laser scans, and they are easily performed without disturbing the workers, saving some work time for the company.
Let’s take the example of what was one of the flagship issues of the marine industry in 2017: the implementation of the Ballast Water Management Convention (BWMC).
With the BWMC, lots of marine companies had to retrofit their ships’ ballast water treatment systems, causing major engineering problems. Shipowners had to change only critical pieces to reduce the cost of this operation, using mainly inaccurate vessel schematics.
To make all this happen before the deadline and with limited expenses, the only viable solution was often 3D laser scanning.
3D laser scanning has the following main advantages:
- Makes it possible to scan difficult surfaces (shiny, dark, etc.)
- Less subject to changing conditions and ambient light sensitivity
- Portable devices
- Simple to use
- Lower cost
In 1849, Aimé Laussedat (referred to as the “Father of Photogrammetry”) used for the first time in history terrestrial photographs to achieve topographic map compilation. Almost two centuries later, we still use his discovery in a lot of different forms.
Photogrammetry is an accurate measurement technique using two or more images taken from different angles to locate 3D position of the points on an object. It’s the reason why it’s a really efficient tool for monitoring the dynamic behavior of a moving object.
This technology is for example used in the energy industry to capture the 3D dynamic response of a wind turbine rotor. Wind turbines being really high and huge constructions, it is necessary to have a long range but still accurate scanning process.
With photogrammetry, the rotor is simultaneously captured at 33 different locations thanks to 4 Charge Coupled Devices cameras. The results are ±25 mm accurate and can be obtained from a maximum distance of 220 m from the engine.
Photogrammetry main advantages:
- Well adapted to capture dynamic responses from moving objects
- Able to obtain 3D files of huge objects
- Easy to use from a long distance
3. Structured light
A brand new measurement system was developed in 1981 by Potsdamer and Altschuler. It was based on the projection of light patterns on an object. These patterns are then captured by a video camera that records their shape to create the three-dimensional model of the object.
One of the main applications of structured light scanners in recent years has been the protection of cultural heritage. Indeed, with a structured light process, you can obtain a full reproduction of a building facade. It is then simple to check for any new deterioration or crack inside the building’s facade to fix it rapidly. The same principle can be used for wooden panel paintings authentication or any other process applied to a flat surface.
Structured light main advantages:
- Very fast scan times (down to 2 seconds per scan)
- Possible to scan large areas (48 inches per single scan)
- High resolution (up to 16 million points per scan and point spacing of 16 microns)
- High accuracy (up to 10 microns)
- Safe for humans and animals to be scanned
- Large range of prices
4. Optically tracked 3D Scanners (Probe positioning system)
Quality control requirements are evolving really fast in the majority of industries. Businesses need a simple, fast and versatile tool to keep a standard quality on their production lines. This tool is the optically tracked 3D scanner. The technology is based on a probe, tracked by a set of cameras to define its exact location relative to the object.
The device is very small and carried by hand, so it isn’t affected by the instability of the environment.
For example, it’s the perfect 3D scanning solution for an automobile production line, where every piece needs to be the exact replica of the other. The quality control officer can easily go around the car he needs to inspect, scanner in hand, without interfering with the workers carefully placing the motor inside.
Optically tracked 3D scanners advantages:
- Extendable scanning volume
- Fast scanning speed
- Ergonomic portable device
- Good results with challenging materials
- Not subject to environment sensitivity
How we use 3D scanners at Ivaldi Group
At Ivaldi, we developed a Parts Replacement as a Service (PRaaS) solution, reducing the inventory needed to zero and improving reactive maintenance thanks to rapid and efficient on-demand spare parts manufacturing.
The key factor behind the PRaaS system is the rapidity and simplicity in which the demands and parts deliveries are treated. Indeed, we are allowing organizations to send 3D files instead of physical parts. A dematerialised file can be sent and received in a minute, but physical objects have to pass through a lot of logistic steps in order to arrive from one place to another. This supply chain takes a lot of time, and as everyone knows, “time is money” for a business.
With 3D printing, you can easily create even the most complex of shapes. If you associate this with the ability of a 3D scanner to duplicate a physical object in a 3D file and the fast evolution of materials characteristics, you can obtain any possible spare part quite easily for a fraction of the cost of a traditional part that is shipped from one end of the world to the other.
If you put this principle into perspective in the field, your breakdown maintenance becomes even easier to achieve, simplifying the job for your repair engineers with specific spare parts from any imaginable shape or dimension.
Our team at Ivaldi is currently working with the FreeScan X5 Handheld 3D Laser Scanner from Shining3D. Why this particular one among the wide range of 3D scanners available on the market?
The answer is quite simple: for its great versatility.
This ultra-portable handheld 3D laser scanner allows us to get highly accurate 3D files from objects of different shapes and sizes directly on the field without disturbing the people working there. Its small size, low weight (0.95 kg) and ease of use makes it the perfect tool for direct field application. In addition to this, it has very good scanning capabilities, with a speed of 350,000 points/s and an accuracy up to 0.03mm, allowing a simplified 3D printing of the final piece.
To summarize, it is a tool perfectly adapted to our needs as a company operating with additive manufacturing technologies applied to complex technical parts.
Each scanning solution has its own advantages and disadvantages, so it is important to choose the right tool for each specific situation.
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