Top 10 Coordinate Measuring Machine Brand & Manufacturers

What is a Coordinate Measuring Machine

A coordinate measuring machine (CMM) is a highly precise device used to measure the physical dimensions and geometric features of an object. It operates in a three - dimensional space, accurately determining the X, Y, and Z coordinates of points on the object's surface. CMMs are equipped with a probe that can be either contact - based (touching the object) or non - contact (using optical or laser sensors). The data collected from the probe's interactions with the object is processed to generate detailed measurements, which can be used for quality control, reverse engineering, and inspection purposes.

History of Coordinate Measuring Machine

The concept of coordinate measurement dates back to the mid - 20th century. The first CMMs were developed in the 1950s and 1960s, mainly in the context of the growing need for precision measurement in the automotive and aerospace industries. These early machines were large, cumbersome, and had relatively limited accuracy. They were mechanical in nature, relying on manual operation and basic measuring techniques. As technology advanced, especially with the development of electronics and computer - controlled systems in the 1970s and 1980s, CMMs became more accurate, faster, and easier to operate. The introduction of digital controls and software - based measurement algorithms revolutionized the field. Today, CMMs are used in a wide range of industries and have become an essential tool for ensuring product quality and precision manufacturing.

Purpose of Coordinate Measuring Machine

• Quality Control in Manufacturing: In industries such as automotive, aerospace, and electronics, CMMs are used to verify that manufactured parts meet the required design specifications. By measuring critical dimensions, form, and position tolerances, manufacturers can identify defective parts early in the production process, reducing waste and ensuring product quality. For example, in the production of engine components, CMMs can measure the cylinder bore diameter, piston ring grooves, and valve seat dimensions to ensure proper engine performance.
• Reverse Engineering: When a physical object needs to be replicated or modified, but the original design data is unavailable, CMMs can be used for reverse engineering. They scan the object's surface to create a digital 3D model. This model can then be used to analyze the design, make improvements, or create new parts. For instance, in the restoration of classic cars, CMMs can be used to accurately measure worn - out parts for reproduction.
• Assembly Verification: In complex assembly processes, CMMs are used to ensure that parts fit together correctly. By measuring the mating surfaces of components, manufacturers can identify any misalignments or dimensional discrepancies that could affect the overall assembly. This is crucial in industries like aerospace, where the proper fit of parts is essential for the safety and performance of aircraft.

Principle of Coordinate Measuring Machine

Contact - Probe Principle: In contact - based CMMs, a probe with a stylus tip touches the object's surface. When the stylus makes contact, a small deflection occurs. This deflection is detected by a transducer, which converts it into an electrical signal. The machine's control system then calculates the position of the contact point in the X, Y, and Z coordinate system based on the known geometry of the probe and the movement of the axes.
Non - Contact Probe Principle: Non - contact CMMs, such as those using laser or optical sensors, work on different principles. For example, laser - triangulation sensors project a laser beam onto the object's surface. The reflected laser light is captured by a camera. By knowing the angle of the laser projection and the position of the camera, the distance from the sensor to the object's surface can be calculated using trigonometry. This distance information is then used to determine the 3D coordinates of points on the object.

Features of Coordinate Measuring Machine

• High Accuracy: CMMs can achieve extremely high levels of accuracy, often in the range of a few micrometers. This high precision makes them suitable for industries where tight tolerances are required, such as aerospace and medical device manufacturing.
• Versatility: They can measure a wide variety of objects, from small, intricate parts to large, complex assemblies. Different types of probes can be used depending on the nature of the object, whether it's a soft material that requires a non - contact probe or a hard metal part that can be measured with a contact probe.
• Automated Measurement: Modern CMMs are often equipped with computer - controlled systems that allow for automated measurement routines. The operator can program the CMM to measure specific points or features on the object, and the machine will execute the measurement sequence precisely. This not only saves time but also reduces human error.[!--empirenews.page--]
• Data Analysis and Reporting: CMMs come with software that can analyze the measured data. The software can calculate geometric dimensions, tolerances, and generate detailed reports. These reports can be used for quality control documentation, process improvement, and communication with other departments or customers.

Types of Coordinate Measuring Machine

• Bridge - Type CMM: This is one of the most common types. It has a bridge - like structure that spans the measuring table. The probe is attached to a moving carriage on the bridge, which can move in the X and Y directions, while the measuring table can move in the Z direction. Bridge - type CMMs are known for their high accuracy and are suitable for measuring medium - sized to large objects.
• Gantry - Type CMM: Gantry - type CMMs have a large, gantry - like structure. The probe is mounted on a moving carriage that can move along the gantry in the X direction, and the gantry can move in the Y direction. These CMMs are often used for measuring very large objects, such as aircraft components or large - scale industrial machinery.
• Articulated Arm CMM: Articulated arm CMMs consist of a multi - jointed arm with a probe at the end. The arm can be rotated and positioned in various ways to reach different parts of the object. They are highly portable and flexible, making them suitable for on - site measurements, such as in a manufacturing plant or during the assembly of large structures.
• Horizontal - Arm CMM: In horizontal - arm CMMs, the measuring arm extends horizontally from a fixed base. The probe can move along the arm in the X direction, and the arm can be rotated or moved in other directions to access different parts of the object. These CMMs are often used for measuring large, flat objects or for applications where the object is difficult to access from above.

Precautions for using Coordinate Measuring Machine

• Probe Calibration: Regular calibration of the probe is essential to ensure accurate measurements. Calibration should be done using certified calibration standards and following the manufacturer's procedures. Incorrect calibration can lead to significant measurement errors.
• Environmental Conditions: CMMs are sensitive to environmental conditions such as temperature, humidity, and vibration. They should be operated in a controlled environment with stable temperature and humidity levels. Avoid placing the CMM near sources of vibration, such as large machinery or heavy - traffic areas. Fluctuations in these conditions can affect the accuracy of the machine.
• Proper Programming: When using automated measurement routines, proper programming is crucial. The operator should ensure that the measurement paths are correctly defined, and the probe approach and retraction angles are appropriate. Incorrect programming can cause the probe to collide with the object, damaging the probe or the object.
• Maintenance: Regular maintenance of the CMM is necessary to keep it in good working condition. This includes cleaning the guideways, lubricating the moving parts, and checking the electrical connections. Follow the manufacturer's maintenance schedule and guidelines to ensure the longevity and accuracy of the machine.

Things to consider when purchasing Coordinate Measuring Machine

• Measurement Requirements: Determine your specific measurement needs, such as the size of the objects you will be measuring, the required accuracy, and the types of features you need to measure. For example, if you need to measure very small, high - precision parts, you may need a CMM with a high - accuracy probe and a small measurement volume. If you're measuring large, complex structures, a gantry - type or articulated - arm CMM might be more suitable.
• Accuracy and Repeatability: Consider the accuracy and repeatability specifications of the CMM. The accuracy of the machine should meet or exceed the requirements of your application. Check the manufacturer's data on accuracy and repeatability, and if possible, request a demonstration or sample measurements.
• Probe Options: Evaluate the available probe options. Different probes have different capabilities, such as contact probes with different tip geometries and non - contact probes with varying measurement ranges and resolutions. Choose a CMM that offers the probe types that are suitable for your measurement tasks.
• Software Features: The software that comes with the CMM is an important consideration. Look for software that is user - friendly, has powerful data - analysis capabilities, and can generate the types of reports you need. Some software may also offer features such as CAD integration, which can be useful for reverse engineering and comparison with design models.[!--empirenews.page--]
• Cost and Budget: CMMs can vary widely in price depending on their type, accuracy, and features. Set a budget and look for a CMM that offers the best combination of performance and cost - effectiveness. Consider not only the initial purchase cost but also the cost of maintenance, calibration, and any additional accessories or software over the life of the machine.

Terms of Coordinate Measuring Machine

• Coordinate System: A three - dimensional system (X, Y, Z) used to define the position of points on the object being measured. The CMM uses this coordinate system to record the measurements of the object's surface.
• Probe Stylus: The tip of the probe that makes contact with the object (in contact - probe CMMs) or is used to sense the object's surface (in non - contact probes). The shape and material of the probe stylus can affect the accuracy and suitability of the measurement for different types of objects.
• Tolerance: The acceptable range of variation in the measured dimensions of an object. CMMs are used to check if the measured dimensions of a part fall within the specified tolerance limits.
• Measurement Uncertainty: A measure of the doubt or error associated with a measurement. It takes into account factors such as probe accuracy, environmental conditions, and the measurement process itself. Understanding the measurement uncertainty is important for accurate quality control and decision - making.