In today's age of digitalization, 3d scanning has stepped up to cover the gap between the material and digital world. The recent exponential growth of newly developed technologies inevitably bore the idea and consequently rendered possible the digitalization of three-dimensional objects.
The process of acquiring three-dimensional data based on real objects can be a challenge, especially when the object's geometrical complexity is high, such as that of a mechanical component of a car. Depicting a complex object's geometry on a computer had previously been painstakingly time-consuming.
However, the development of powerful computing systems have made it possible to depict not only an object's geometrical, but also its chromatic information with great time-efficiency and to establish a continuously evolving market for 3D scanners.
3D scanning allows for a faster three-dimensional digitalization as compared to other more conventional methods. Having established its position as the most convenient way to depict the shape of an already existing object, it can be applied in multiple sectors, not only including marine shipping, automotive industries, architecture, design and modelling, packaging, but even medical and scientific sectors and academic research.
Once you are holding a digital copy of your object, inspecting as well as modifying its geometry can be done in an instant. Even the production of identical copies of your original object with whatever processing method is most convenient to your application's needs becomes no more than a matter of taking the decision to do so.
Techniques of 3D Scanning
The use of a three-dimensional Scanner results in the acquisition of a dense point cloud based on the surface of the respective object, the processing of which leads us to the final three-dimensional model. The aforementioned points share an identical cartesian coordinate system. Each of them carries information that places it at a precise position within three-dimensional space, which corresponds to a position on the surface of the object that has been digitalized.
3D Scanners can be categorized based on a multitude of criteria. Nonetheless, the two most prevalent categories are linked to the method of gathering the point cloud of the object's surface, differentiating between those that utilize physical contact with the object and those that don't. Thus, the two categories one can find on the market currently refer to contact and non-contact 3D Scanners. In their turn, non-contact 3D Scanners can be broken down into active or passive scanners. Each one of the aforementioned categories embodies a variety of technologies.
Categories of 3D Scanners
Contact 3D Scanners explore the object by coming into physical contact with it while the object is placed on a specific flat surface. In case that the object's curvature prevents it from assuming a stable position on any surface, it will be held by an additional accessory.
This method holds various disadvantages due to the contact of the scanner with the objects, as this might alter their geometry.
The development of non-contact 3D Scanners provided a solution to that problem, as they operate based on active as well as passive approaches so as to capture the object without altering it.
The majority of active 3d scanners emit a certain kind of radioactivity or light. In that way, either the absorption of the radioactivity or the reflection of the light are measured and thus the representation of the object (or the space) is achieved.
The most common types of emission are those utilizing light, ultrasound as well as x-rays.
While active scanners emit light or radioactivity themselves during the scanning process, passive scanning techniques are based on reflected radiation of the environmental light and detect visible light since it is directly available.
Scanners utilizing passive techniques are cheaper compared to those that rely on an active approach, as in most cases they do not require any further specific hardware than mere digital cameras.
Three-dimensional scanning, as mentioned previously, can be applied in a multitude of sectors and industries. Namely, some of its most frequent applications would be in quality control and reverse engineering.
The process of scanning often represents the easiest part of digitalization, while the creation of an accurate three-dimensional representation of an object with irregular surfaces usually requires time and a high amount of manual labor.
While three-dimensional scanning is an important new tool for the documentation of objects with high complexity, it is only one part of a digitalization project, taking into consideration that the mere collection of data is not enough.
Since the time needed in order to create an accurate three-dimensional model is often higher than the time required for the actual scanning, a high level of focus needs to be given to the data processing stage that follows the scanning process. The steps that are completed during the data processing stage aim to make effective use of the data provided by the scanner.
In its entity, the process of digitalization - that is the series of steps from the data depiction up until the final visual representation of the three-dimensional data model - includes the collection of geometrical data, the alignment and consolidation of the individual scans, their conversion into a polygonal mesh and finally the simplification of the mesh as well as the elimination of any eventual geometrical disruptions (the geometrical reconstruction where gaps have been detected).
The end-result of this process is an stl file.
In case of reverse engineering applications, this file is used as a reference point for the reconstruction of a three-dimensional model that can be read by modern construction machines.
On the other hand, in case the scanning is performed for the inspection of an object, the process is slightly shorter as it does not require the creation of a 3d model after developing the polygonal mesh (stl file). To the contrary, the mesh is compared to the already existing three-dimensional digital model in order to confirm the physical object's accuracy versus the ideal standard model.
Metallurgy - Quality Control
Metalpol has applied 3d scanning to the Quality Control department for its produced casting parts. Utilizing an automated 3D scanning system consistent of a scanner and a rotary table, the scanning process of heavy and large-sized castings can be accomplished swiftly. Thanks to a strict quality control process, the manufacturer now has the possibility to evaluate a test casting comparing it to a CAD model provided by the client. After the test casting has been approved by the responsible department, a full quality report is sent to the client, based on which the latter can provide approval for the commercial production of the end-product. Applying three-dimensional scanning to their process reduced the time needed until commercial production by 300% while simultaneously reduced costs by 10.000€ on a quarterly basis.
Automotive Industry - Reverse Engineering
Introducing three-dimensional scanning to their maintenance department, allowed for Cooper Standard to create a fully digital library of the molds used during production. Now, the preparation of new shapes and tools is not only faster, but above all less costly. As a result of the application of 3D Scanning, "Cooper Standard" has reduced the average production time by 400% while also lowering costs by 500%, saving more than 15.000€ by quarter.
Plastic Industry - Rapid prototyping
The utilization of three-dimensional scanning in ROSINSKI's R&D department, allowed for lower cost as well as faster improvement of the molds and tools used in production. The modification of tools and prototypes can now be completed twice as fast, directly accelerating commercial production of customer products and leading to substantial savings.
The exponential growth in powerful computing systems and the dramatic improvement in the sector of three-dimensional real-time graphics are playing a major role in the development of three-dimensional scanners as well as in their increased popularity. Consequently, today's possibilities to manage complex three-dimensional geometry on low-cost platforms, enable the visualization of detailed and highly accurate three-dimensional models. As computing systems will keep evolving, continuous and sustained growth of 3d scanning technologies is to be expected, providing us with ever improving results.
Exploiting current developments and the advantages 3d scanning has to offer, GE SUPPLiES provides highly qualitative services of reverse engineering and geometric inspection, ensuring maximum accuracy which cannot be achieved with other conventional methods.
Through usage of specialized processing software after the scanning of an object, GE SUPPLiES’ clients receive colour imaging files of high accuracy that can be used for immediate and user-friendly comparison of the actual object to the initial three-dimensional file, quality control reports that include complete analysis and capture of the dimensional deviations from the initial design, as well as mechanical and three-dimensional drawings.