Cnc coordinate measuring machine

Types of CNC Coordinate Measuring Machines

A CNC coordinate measuring machine (CNC CMM) is a type of CMM that employs computer numerical control to automatically position the measurement probe of the machine. Here are some measuring machines that are computer-controlled.

• CNC Bridge Coordinate Measuring Machine:

The bridge CMM is the most classical and widely available design. In a bridge CMM, a horizontal measuring bridge/beam moves across vertical columns. The probe descends from the bridge and touches the object to be measured. The machine carries out point-by-point measurements and formally outlines the object's features, including dimensions and geometries. The device can then be used for quality control.

Although the bridge machine effectively coordinates measuring tasks, its accuracy may be impacted by environmental conditions and thermal expansion. Therefore, the device is best suited to stable areas with controlled temperatures.

• CNC Gantry Coordinate Measuring Machine:

A gantry CMM measures an object with a horizontal crossbeam that is supported by vertical legs. Huge workpieces are typically measured using gantry CMMs because they generally feature an open design that allows for the easy measurement of sizable and heavy components.

Gantry CMMs, in contrast to bridge CMMs, are often more appropriate for measuring huge workpieces because they have greater measurement ranges and allow for easier access to the component under consideration from various angles. As a result, they are suitable for applications in industries that need the measurement of large components. The aerospace and automotive industries are examples of this.

• CNC Horizontal Arm Coordinate Measuring Machine:

CNC horizontal arm CMMs have an arm that extends horizontally. The arm features movement along its own axis, as well as vertical and transverse movements to position the measuring probe accurately. The machine is designed for the easy measurement of medium to large-sized workpieces with complex geometries.

As a result, many designs of the horizontal arm CMM are lightweight and extremely portable. They can be taken directly to the item to be measured rather than measuring the workpiece in an awkward position.

Specifications and Maintenance

• CMM Size and Measurement Range: Coordinate measuring machines (CMMs) are available in a number of sizes, and their measurement range corresponds with their size. Typically, the size will be expressed as length x breadth x height, and it will be written in millimeters (for example, 1000 x 800 x 600mm). This means that this particular CMM is capable of measuring objects with maximum dimensions of 1000 millimeters in length, 800 millimeters in width, and 600 millimeters in height. The measurement range of a CMM machine refers to the entire volume or space that it can measure. It is extremely important to match the size and measurement range of a CMM to the workpieces that need to be inspected.
• Measurement Accuracy and Resolution: The accuracy and resolution need to be taken into account when CMMs are chosen. The accuracy of a CMM machine defines the maximum deviation it can produce when measuring an object's dimensions. This error can be influenced by a number of factors, for example, environmental conditions, probing forces, and uncertainty factors. The accuracy of a CMM is seen in three main aspects: omnidirectional positioning accuracy, linear positioning accuracy, and angular positioning accuracy. The resolution of a CMM refers to its ability to grasp a small dimension change, and it relies heavily on the measuring probe and electronic components of the machine.
• Measuring Probes: When it comes to measuring probes, users have to consider the types and features of the CMM probe options, their compatibility with workpieces, and the requirements for measuring accuracy. CMMs can be equipped with a variety of probes to suit different measuring requirements. These include contact probes, optical probes, laser probes, and others. The material of the probe tip also has an impact on workpiece features. For example, ceramic, ruby, and other materials are suitable for measuring metal and plastic workpieces. On the other hand, measuring workpieces that have a textured surface will require the use of a probe with a smooth surface.
• Environmental Control and Calibration: A CMM benefits from a stable environment in which to operate, and this helps to maintain its precision and prolong its lifespan. Therefore, the following environmental factors must be taken into account when choosing a CMM: temperature and humidity, airflow and dust, vibration and noise, and lighting. The machine must also be calibrated periodically to ensure measurement accuracy and reliability.

In terms of maintenance, the following points must be adhered to in order to ensure that the CMM works well and consistently delivers high-precision measurements.

• Regular Cleaning: The surface of a CMM machine should be wiped with a lint-free cloth at least once a week. A small amount of neutral detergent or alcohol can be used to dampen the cloth. Use only the specified cleaning solution for electronic components and sensors.
• Check and Tighten Parts: Fixing components are required to be checked and fastened monthly to ensure that there is no looseness in the fasteners. The probes, measuring rods, and other measuring accessories should be checked monthly to ensure that they are not fastened and do not have any abnormality. The precision of a CNC coordinate measuring machine can be effectively maintained by slightly changing the probes according to the geometry of the workpiece to be measured.
• Regular Lubrication: The CMM machine's track rails, rotating shafts, and other movable parts should be oiled according to the schedule.

Scenarios for a CNC coordinate measuring machine

Due to its precision, efficiency, and ability to handle complex measurement tasks, the CMM machine has become an inevitable tool in various industries.

• Manufacturing industry: In the manufacturing industry, Coordinate Measuring Machines are mainly used for quality assurance and control. They can check various parts and components against their CAD designs to ensure they are within the desired tolerance levels. This helps to identify any potential issues early in the manufacturing process, reducing scrap and rework.
• Aerospace industry: The Aerospace industry demands the highest levels of precision and quality. A probe CMM measures the dimensions of parts and components used in aircraft and spacecraft to ensure they meet the strict tolerance required. They are used to measure everything from small brackets and fittings to large structural elements.
• Automotive industry: In the automotive industry, CMM measures the dimensions of parts and components used in vehicles, including engine blocks, transmission housings, body panels, and chassis components. They are also used to measure tooling and fixtures used in the manufacturing process to ensure they are within the desired tolerance levels. 3D CMMs check directly measure the geometry of automotive components using laser technology. The information is then used to optimize manufacturing processes, improve product quality, and reduce defect rates.
• Heavy industry: Coordinate measuring machines can inspect large-scale components, like those used in construction, power generation, and mining industries, to ensure quality and precision, especially for large parts that don't fit traditional inspection tools.
• Medical device industry: Medical Device Designers and manufacturers often use CNC Machines to measure complex parts, such as orthopedic implants, surgical instruments, and diagnostic equipment. These devices have to meet stringent regulatory requirements and must be designed and manufactured with the highest levels of precision.
• Mold and die industry: The Mold and Die indutry highly depend on measuring machines, especially the 3D type, to ensure the molds and dies' accuracy, quality, and repeatability that are used for complex shaping processes in various industries, such as automotive, consumer electronics, and aerospace.

How to choose a CNC coordinate measuring machine

• Determine the measuring volume:

  Measuring range is the first factor to consider when selecting a CNC CMM. Measuring volume refers to the maximum dimensions that a CMM machine can measure, usually in length X, width Y, and height Z. It is crucial for users to choose a CMM device whose measuring volume meets their measurement needs. For example, they may measure large workpieces if they measure large workpieces, so they need to choose one with a large measuring volume. In contrast, a smaller measuring volume may suffice if they measure small workpieces.

• Consider the measurement accuracy:

  Precision is another critical factor in selecting a CMM. Accuracy describes the machine's ability to measure the actual dimensions of an object. Users should select a CMM whose accuracy meets their requirements for workpiece measurement. For instance, if the user needs to measure highly accurate workpieces, they must choose a one with higher precision. Otherwise, a lower-precision one may be sufficient.

• Weigh the CMM type:

  Users should first understand the different types of CMMs available on the market and choose the one that best suits their needs. For example, a user who needs to measure workpieces with complex shapes and contours may choose a vision system CMM. In contrast, a larger size one may suffice for a user who measures large workpieces.

• Considering the budget:

  When selecting a CMM, users should consider their budget and choose a machine that meets their needs and budget constraints. Users can compare the benefits and features of different models and brands to find a model that offers good value for money.

Q&A

Q1: How does a CNC CMM machine work?

A1: The device measures an object's coordinates by probing the object's geometry with a probe guided by a computer. The object's data is then used for the desired application, such as quality control or reverse engineering.

Q2: What are the capabilities of a CNC coordinate measuring machine?

A2: These machines have several capabilities. They are mainly used for inspection and quality control applications. They can also be used for the following: reverse engineering, tooling verification, first article inspection, assembly check, profile measurement, data acquisition, surface mapping, anddot measurement

Q3: What are the different types of coordinate measuring machines?

A3: There are four main types of CNC CMM. They include: (1) Bridge Coordinate Measuring Machine (2) Gantry Coordinate Measuring Machine (3) Horizontal Arm Coordinate Measuring Machine (4) Vertical Coordinate Measuring Machine

Q4: What Are The Benefits Of A CNC Coordinate Measuring Machine?

A4: The machine offers improved accuracy. It also enhances productivity and is easy to use. It integrates well with various software and automation systems. The device also offers flexible measuring solutions. It can measure different kinds of objects with complex geometries.