What Is a Coordinate Measuring Machine?

In today’s manufacturing industry, automated processes and highly accurate product verification systems are the norm to remain competitive. Consumer demands for complex product innovations and quality are becoming more stringent, and manufacturers must balance these two goals without sacrificing consumer confidence or brand reputation.

Coordinate measuring machines (CMMs) are one tool essential for quality control. They accurately measure objects and complex workpieces to streamline operational processes and reduce downtime. These machines can perform crucial measurement functions faster, more precisely and automatically record the inspection results.

Coordinate Measuring Machine Definition

A CMM is a piece of advanced metrology equipment that accurately measures the complex geometries of various objects. CMMs are some of the most accurate measuring systems on the market today.

The measuring process involves using a contact probe to establish discrete points on an object’s surface. The machine measures an object’s length, width and depth using coordinate processing technology. Many types of coordinate measuring machines exist, each with its specialized application. However, they all perform the same critical measurement function.

What Is a Coordinate Measuring Machine Used For?

A coordinate measurement machine is a necessary tool for inspecting parts and components in various industries to ensure they meet design requirements. As these machines can measure an object in three dimensions with high accuracy, they can detect minute flaws that might render the component unusable, providing a critical layer of safety and quality control.

Each type of CMM has features that make it suitable for particular applications. They are used in various industries to measure parts of all shapes and sizes, from quality critical components in aerospace to precision parts in the biotechnology industry.

How Coordinate Measuring Machines Enhance Quality Control

CMMs allow users in various industries to meet ever-increasing demands for flexibility, efficiency and accuracy. These machines offer the following advantages:

  • Boosting efficiency: A CMM can considerably reduce production time, streamlining the manufacturing process’s inspection stage while maintaining high-level accuracy and precision. Some models are also designed to save space in busy manufacturing settings. These machines can also reduce waste by preventing component non-conformance down the production line.
  • Enhancing quality assurance: CMMs eliminate human error in manufacturing processes. Once programmed for a part’s configuration and dimensions, they can perform automated inspections on as many parts as necessary.
  • Facilitating customization: Depending on the CMM, the machines also support specialized software programs, which operators can upgrade to maximize efficiency and adapt to evolving manufacturing requirements.
  • Improving brand reputation and customer satisfaction: Manufacturing operations rely on quality assurance to ensure customers receive the highest quality products. CMMs allow manufacturers to consistently verify that conformal parts are produced thereby, building a solid reputation and leading to repeat customers.

How Does a Coordinate Measuring Machine Work?

A CMM measures objects with a probing system. Depending on the machine type and application, the probes can measure objects differently, including through direct contact, lights and lasers. They track probe tips and create dimensional measurements via discrete contact points. Most CMMs are designed with similar parts, including:

  • Probes: Probes use direct contact or contactless methods such as lights and lasers to achieve accurate measurements. All CMMs use probes to measure objects, regardless of their structure and design. Probe tips are often spherical, with hard materials at the tip, such as ruby or zirconia.
  • Structure: The machine’s structure refers to its overall form, specific design and construction materials.
  • Metrology software: The software is integral to a coordinate measurement system. It collects, analyzes and displays the measurement data in real time.
  • Controller: The controller determines the machine’s output by directing the command to the motors and probes and making adjustments depending on the part. CMM controllers are automated in large operations, but operators can perform these tasks manually if required.
  • Granite table: Accurate measurements often rely on the measurement surface, which is usually a stone surface plate. Granite tables are standard in CMMs as they show little degradation over time and withstand high-level operations.
  • Fixtures: The fixtures are another critical element of CMMs as they hold the component in place for measurement. Any movement leads to significant errors, and most CMMs use a combination of fixture plates, magnets and clamps to keep the object still.

What Is Remote Coordinate Measuring Machine Programming?


Remote CMM programming allows dimensional inspection experts to develop and coordinate measurement machine programs and routines remotely without needing a direct connection to the machine. It’s an advanced programming method that offers significant advantages, including:

  • Efficiency: Remote CMM programming allows skilled programmers to create measurement routines from anywhere, providing greater resource capacity and scheduling flexibility.
  • Streamlined processes: Eliminating the need for a physical presence to coordinate measuring machines and allowing experts to develop routines from anywhere optimizes machine use.
  • Versatility: Remote programming enables users to access measurement process expertise, enabling collaboration and easy sharing of best practices across teams.
  • Cost savings: Programming CMMs remotely can save time and reduce costs, reducing downtime and potential risks associated with single resource programming.

Types of Coordinate Measuring Machines

Coordinate measuring machines come in many variations to suit different environments, industries and applications. They all have three orthogonal axes — X, Y and Z. These axes work together to create a 3D coordinate system.

Four main types of CMM exist, including:

1. Bridge

Bridge machines allow probes to move along the three axes, allowing precise measurements of an object’s service through a point cloud. They have a basic and resilient structure and are often cost-effective to build and maintain. These machines suit small- to medium-sized parts, although they may require a forklift or truck to place them on the machine, which can pose some risk to the machine itself. They are highly accurate, making them ideal for measuring machined parts with tight tolerances.

2. Gantry

These CMMs are similar in structure to bridge machines but often considerably bigger. Gantry machines have a bridge on pillars, allowing higher overall measuring volumes. They feature a robust foundation and are usually mounted to the floor, making loading and unloading heavy parts safer.

Gantry machines are highly accurate, and programmers have easy access, making programming more straightforward. Due to their ability to measure large, complex components, these machines are popular in the aerospace industry.

3. Cantilever

These machines are ideal for measuring small parts as they give operators open access on three sides. The measuring head is only attached to one side of a rigid base. They move quickly, providing high levels of accuracy and low measurement uncertainty. They’re a common choice for measuring gauges and other master parts and are popular on shop floors as they’re easy to set up for automatic loading and unloading.

4. Horizontal Arm

Horizontal arm CMMs are ideal for measuring large surfaces or hard-to-reach features. These machines can measure large, thin-walled components such as sheet metal. Two types of horizontal arm machines exist:

  • Plate-mounted horizontal arm machines: These machines have a column mounted on a large surface plate. They are often side-mounted to ensure accuracy and stability.
  • Runway-mounted horizontal arm machines: These machines run on a dedicated beam with no integral plate. They have a dual arm, allowing operators to simultaneously measure both sides of an object.

Trust Unitek Technical Services With Your Quality Assurance Needs

Quality assurance and control are the backbone of successful manufacturing. It lets you maintain your reputation and boost efficiency without sacrificing product performance. NTS Unitek’s services can help you deliver products customers can trust, enhancing quality while mitigating risks and lowering costs. We verify and support the supply chain so you can focus on your organizational goals and core competencies.

NTS Unitek and technical specialists have many year of success in verify the customer product requirements. We can support you through all your quality assurance needs. Contact us today to learn more about our commitment to quality people and quality results.