3D metrology is the scanning and measuring technique used in various industries to design new parts, perform quality control checks on existing components, or monitor machines and their processes. It allows manufacturers to produce precision-engineered parts that meet high-quality standards.
Let’s examine the basic tools in today’s metrology and how they’re used. Let’s also review the fascinating history of the science of standardized measurement.
What is 3D Metrology?
3D metrology is the field of science focused on measurement in three dimensions. Capturing data of an object in three dimensions allows for the accurate reproduction of that object.
3D metrology is exact, measuring and recording millions of data points on the scanned object. This would be the equivalent of measuring by hand millions of times the distance and location of one area on the object in relation to other places. The massive dataset of coordinates and spatial measurements a scan creates forms a digital cloud that software can process to replicate the original object.
The History and Evolution of Metrology
3D metrology is modern, but it has long been a part of the story of humankind. There’s no way of knowing which group of people was the first to standardize measurements, but the ancient Egyptians received credit because they left a written record.
As part of the pyramid's construction bearing his name, Pharaoh Khufu ordered the builders to use an agreed-upon kingdom-wide measurement of a cubit — a selection of granite served as the official standard. The Egyptians cut it to conform to the length from the Pharaoh’s elbow to the end of his middle finger. The width matched that of the Pharaoh’s hand.
Deviating from the standard cubit carried the death penalty. No wonder the resulting pyramid is so precise. The measurements of the four sides of its square base are within 1/20 of 1% of each other.
Today, metrology relies on more precise measurements than the length of a monarch’s limb. Computers and sensors have greatly advanced metrology.
Sensors allow for continual around-the-clock monitoring of systems challenging to access, such as remote underground pipelines. The sensors can measure the pressure the pipelines are enduring and alert technicians to the danger of malfunctions and failures.
Computers can calculate incoming data from sensors and other devices far faster than humans. This speed allows computers to present comprehensive data to decision-makers promptly to prevent potential problems.
Key Tools in 3D Metrology
Modern manufacturers can choose from a variety of metrology instruments, such as the coordinate measuring machine (CMM).
CMM
Coordinate measuring machines have physical probes that make contact with specific points along the object's body. The programmed points create enough raw data for computer software to construct a 3D model later.
Operators can also use the dataset to build a physical object using devices like a computer numerical control machine (CNC). The detailed digital input aids the CNC in following precise directions to fabricate needed parts.
CMMs can be large, stationary machines or small portable models. This adaptability is one of the primary reasons modern metrology plays such a huge role in several industries.
A CMM’s physical contact makes it highly accurate. Unfortunately, its need to touch the object on multiple planes renders it less suitable for complex geometry. It simply may not be able to access recessed and hidden sections of the object.
Laser Scanners
Laser scanners and 3D scanners are examples of non-contact systems. Using light, they can scan even complicatedly proportioned objects.
Some combo systems combine lasers with probes, offering two ways of gathering data. The two methods make it more likely that all the key areas of the object will receive measurement, even if recessed.
Optical and Sound Scanners
Most people only think of visual scanners, such as those using lasers. But there are also scanners that use cameras and sound.
Like their laser counterparts, they are relatively lightweight, making them portable. They also have a distinct advantage over physical probes when measuring delicate objects. Sound and light are far less likely to damage the object, which is essential when the object is delicate or sensitive to touch.
Software
The data the scanners capture isn’t helpful until it undergoes data processing. Specialized software takes the raw data and structures it into a 3D model. The 3D model then receives analysis according to how well it matches a CAD reference.
When is 3D Metrology Needed?
The use of metrology is only limited by imagination. However, four principal areas where you'll find it are prototyping and design, quality control, reverse engineering, and complex manufacturing.
Prototyping and Design
Creating prototypes using 3D technology saves time and money. For starters, you can bring the prototype to life on screen simply by processing your captured data points. However, if you need to fabricate a physical object, you can also relay your processed data to a 3D printer.
In turn, the printer uses less raw material than traditional processes. It builds layer by layer, using only what’s necessary. This is opposed to working with a block of expensive raw material and chipping away at the excess to create a product.
The speed of 3D fabrication permits companies to adapt quickly to changing needs. They can test new designs promptly to respond to rapidly evolving situations.
Disasters connected to aerospace components or medical device parts often highlight the life-and-death importance of accuracy in manufacturing. Modern 3D metrology ensures greater fidelity than is possible by human-driven mechanical efforts.
Quality Control
Traditional quality control usually takes place after the manufacturing phase. Parts are either accepted or rejected, and those that don’t pass inspection are either scrapped or recycled.
3D metrology saves money, time, and frustration with its ability to perform quality control checks before manufacturing a part. Light scanners can assess a part under construction, allowing adjustments to occur during manufacturing. The integrated quality control method means the end product meets your specifications, eliminating the need for repeated passes through the manufacturing phase.
Reverse Engineering
Ideally, there’s always a CAD model of a part available. But sometimes, it’s necessary to construct a product without a reference computer data model. You might have to fabricate the end product directly from an existing physical component.
This sort of reverse engineering can be the case when restoring outdated machines no longer supported by manufacturers. For example, automobile restorers of vintage makes and models often need to fabricate new parts by scanning old parts. Similarly, the practice is standard for museum restoration workers dealing with historic machines.
Complex Manufacturing
The more complex the manufacturing, the more errors can become expensive, time-consuming, and sometimes dangerous. That’s why 3D metrology is a standard technology in automobile design and aerospace engineering.
Automobile manufacturers use 3D metrology to develop new major components, such as a more powerful or efficient engine, a smoother transmission, a stronger chassis, or a more aerodynamic body. Like the automobile industry, airplane manufacturers use 3D metrology to create everything from the engine to the landing gear. Building such parts the traditional way would be too costly for either aerospace companies or automobile makers to pursue innovation aggressively.
How 3D Metrology Works
3D metrology thrives on data, gathering it through contact and non-contact methods. For example, it can use a CMM for physical contact measurements. A CMM’s probe will touch specific locations on the object.
A CMM delivers precision measurements, making it ideal when the finished product must conform to tight tolerances. However, the need to physically contact the model means it works best if the object has no overly complicated geometry. A CMM will also operate slower than a light scanner.
A light scanner doesn’t contact the model, using light to capture the contours of an object. Because the scanner doesn’t touch the object, it’s an excellent choice for scanning soft materials that would change shape if touched by a physical scanner’s probe. A fabric-covered item is a good example.
Light scanners are also excellent at scanning oddly shaped objects. Their portability also helps.
The data the scanners capture goes through data processing, converting it into a 3D model. The 3D model is carefully compared against an existing CAD model to determine if there are any areas where it doesn’t match and needs tweaking.
Benefits of 3D Metrology
3D metrology offers several benefits over traditional measuring techniques, including precision, efficiency, cost savings, and versatility.
Precision
3D metrology aims to produce results that match the original object as closely as possible. This high degree of accuracy makes it possible to manufacture replacement parts that don’t need additional customization to fit exactly how they should in even the most complex machinery.
Entire industries rely on precisely measured parts, such as the automobile aftermarket industry. Consumers must feel confident that inexpensive third-party components will align closely with those of the original equipment manufacturer.
Exactitude is often non-negotiable, as in the case of safety equipment. Failure to measure parts correctly could result in tragedy on a massive scale in areas like the airline industry. That’s why experts rely on 3D metrology when accuracy counts the most.
Efficiency
Inspections can be much faster using 3D metrology because a computerized scan can take millions of measurements in seconds. The software can quickly compare data to identify areas of concern.
3D metrology also allows for inspections during manufacturing, avoiding the need to wait until the end of the production phase. This capability creates an opportunity to correct errors early, increasing the likelihood of production remaining on schedule.
Cost Savings
Companies can often use 3D metrology to eliminate the need and cost of constructing a physical model. Gone, too, are the need for tooling and molding. Avoiding unnecessary work also reduces costs both in labor and raw materials.
Versatility
Various industries have adopted 3D metrology because it works well in a variety of settings. Scanners can measure huge components used in gargantuan aerospace, naval, or construction machines as well as delicate parts found in scientific laboratory research and surgical settings.
One key advantage of 3D metrology is the ease with which it can measure unusually shaped objects. A scan can record millions of data points to recreate an accurate representation of the object regardless of the nuances and subtle shifts in its design.
Discover What Metrology Can Do For You
The entire history of metrology has been a search for improved accuracy, quality, and efficiency. 3D metrology improves a company’s ability to advance in all three metrics. Millions of data points render previously unachievable accuracy. The result is a high-quality component produced in less time for less money.
3D metrology can open a new world of manufacturing options. The technology will give you new ways of saving time and money while elevating your production standards.