Are you intrigued by 3D model scanning? Well, who isn’t? It’s a thriving industry with so much possibility in the present, and lots of prospects for the future.
In premise, 3D model scanners come in two forms: structured light and laser scanners. They are used for a variety of applications, starting with creating manufacturing parts to making digital prints of teeth molds.
In this article, we will cover how they work, how to choose a 3D scanner, as well as some purchasing advice.
So if any of that sounds interesting to you, keep reading.
How Do 3D Model Scanners Work?
As mentioned earlier, there are laser scanners and structured light scanners. Even though both work in a similar fashion, there are some very distinct differences that must be brought to light, such as the application and relative precision.
Most laser scanners make use of distance measurements and guided laser beams. Through calculations of the time-of-flight of the laser between the object and the scanner, a distance measurement can be captured.
By taking millions of measurements, one is able to compile a complete image from the single points into meshes and point clouds.
On the other hand, structure light 3D model scanners use projected light patterns and cameras. Because the luminescence from the patters appears blurry and distorted from various perspectives, the scanner can make use of this to create accurate geometric copies of the scanned surface.
Patterns consist of various arbitrary figures and stripes allow the scanner to capture several samples of a surface, thus increasing the speed of measurement.
These projection systems can capture the total surface of the object, and because of the point density will result in highly accurate representations, as well as higher resolutions than that of a laser scanner.
Also, fringe protection systems are meant to be used in closely-monitored and controlled environments with ambient conditions, however, some systems are less strict about these requirements.
For instance, the WLS qFLASH system is quite compact and uses white light to project random patterns on the object, thus analyzing the edge lines and surface qualities through stereo vision. This works best for casting and measurements of edges.
Whereas, blue light scanning results in high-definition of brighter parts of an object. And performs best in variable lighting conditions. A system like this is great for decreasing vibration concerns. It makes use of combined structured light with stereovision, taking the best of both worlds. Thus allowing for greater freedom in condition requirement.
Advice for Choosing A 3D Scanner
When it comes to choosing a 3D model scanner, there are three general considerations that must be made. However, depending on your use case, you might need to tailor the questions.
- The portability of the device
- The accuracy of the device
- One-off measurements or production parts
And that’s about it. Each of these considerations concludes a greater subset of questions, so let’s take a look at that.
Even though most of the measurements are still completed in the lab, many use case scenarios require greater portability for the 3D scanners. Some devices are typically unable to perform in certain conditions, whereas others are exceptionally adapted for such environments.
Factors, such as ambient lighting can play a huge role in the type of scanner that you will need. You also need to consider the personal requirements necessary for the measurements. If you can make all of your scans with the scanner battery, then making use of a scanning arm might be a great solution.
However, if you are in need of more space, a vision system and/or laser tracker is probably your best bet.
The most direct of the considerations to make regards accuracy. If you’re working in the sub-15 µm range, you will need a blue light or structured white system.
If you’re working in the 30 to 50 µm range, a simple portable scanner should be able to contend to your needs.
Type of Measurement
Even though measurement requirements might change time from time, the importance of accurate measurements is of utmost value. If you’re measuring production parts, blue light or white light system will suit you best.
And if you’re measuring one-off objects, a hand-held portable scanner will do the job.
The greatest advantage of a camera system in the use of production objects is that the object can be scanned with reference points, which makes it that certain parts can be quickly imprinted on the fixture with no loss of precision.
Advice for Purchasing A Scanner
In many cases, the accuracy of a scanner can be disingenuous, so before you do buy one, ensure that you have ascertained the coordinate measuring mechanisms. With that being said, you can make use of a part with known surface and dimensions and use that to test the device.
It can be quite easy to get lost in vivid color mappings, but beautiful shading does not ensure that you will get the accuracy that you deserve, not to mention need.
Also, some 3D scanners have a preferred accuracy that a salesperson will often make use of to his advantage. In a demo, ensure that the area of measurement is fully checked and exploited, including the depth of field.
3D Scanning Done Right
Now that you have learned about 3D model scanners, you are well on your way to do whatever you like with this newfound knowledge. In any case, 3D scanners are only looking to become better each year, so there is no rush.
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