Vision Measuring Machines (VMM) are high-precision instruments widely used in various fields that require high-accuracy inspections. Whether in electronic manufacturing, automotive parts production, or precision mold inspection, VMMs play a crucial role. Among the many factors that affect measurement results, thestructural design and stabilityof the equipment are fundamental. Simply put, the design of the structure determines whether the equipment can work stably, and its stability directly influences measurement accuracy.

This article will explore the core components of the VMM, includinghigh-precision granite bases, cantilever structure design, guide rails, and ball screw systems, and how they ensure the stability and accuracy of the equipment.

High Rigidity Granite Base: Stability Starts from the Foundation

The accuracy required for VMMs is extremely high, and even minor vibrations or temperature fluctuations can lead to measurement errors. To address this issue,granite basesare widely used. Granite, as the foundation for VMMs, has many unique advantages:

• Excellent Vibration Damping: Granite’s naturalshock-absorbing propertieseffectively reduce the impact of external vibrations on measurement results. This ability to “block interference” is crucial for high-precision measurements.

• Low Thermal Expansion Coefficient: Granite has a much lower thermal expansion coefficient compared to metals, meaning it can maintain dimensional stability in environments with temperature variations, thereby reducing measurement errors caused by temperature changes.

• High Hardness and Resistance to Deformation: Granite is highly durable and can withstand significant pressure without deformation. This is essential for maintaining stability during heavy-duty operations.

Example: In the inspection of high-precision electronic components such as micro connectors, the measurement tolerance is extremely strict. Even a slight deformation of the base could lead to measurement discrepancies. The use of a granite base helps prevent such issues, ensuring measurement accuracy and stability.

Cantilever Structure: Balancing Flexibility and Stability

VMMs typically have two structural forms:gantry-typeandcantilever-type. The cantilever structure is favored for itssmall footprintandease of operation. The key to the cantilever design is achieving a balance betweenflexibility and stability. Here are the key highlights of cantilever design:

• Symmetrical Support Design: The cantilever structure often adopts asymmetrical supportdesign to ensure balance during movement and avoid shifting due to uneven force on one side.

• Weight Balance: The cantilever beam is typically designed withcounterweightsto offset the inertia generated during movement, ensuring that the equipment does not wobble during high-speed operations.

• High Rigidity Alloy Materials: To increase stability, the cantilever components are usually made of high-rigidityalloy materials, enhancing the equipment's resistance to deformation.

Example: In automated production lines, many components need to be measured continuously and rapidly. The cantilever structure ensures that the VMM can perform precise operations in a short time, reducing measurement errors caused by vibrations or external disturbances.

Precision Guide Rails and Ball Screw Systems: Ensuring Precise Movement

The three-axis system (X, Y, Z) of a VMM needs to move with extreme precision, so the guide rails and ball screw system are critical. Here are the key factors affecting the movement accuracy of a VMM:

1. High-Precision Guide Rail Systems: Smooth and Accurate

High-precision guide railsare widely used in the three-axis system of VMMs. The main benefits of these guide rails include:

• Low Friction Coefficient: High-precision guide rails reduce friction, allowing the platform to move smoothly and reducing positioning errors caused by uneven friction.

• Durability: These guide rails have high durability, ensuring long-term high accuracy even with frequent use. They are well-suited for high-intensity, high-frequency working environments.

• Smooth Movement: The precise guide rail system ensures that the platform moves without generating excessive vibrations or wobbling, effectively maintaining measurement accuracy.

2. Precision Ground Ball Screw: Reducing Backlash

Theprecision ground ball screwplays a crucial role in the transmission system. The advantages of the ball screw system are:

• High Accuracy: The precision grinding of the ball screw reducesbacklash, improving positioning accuracy. This is especially important for VMMs, which require precise control of the platform position at the micron level.

• High Repeatability: The ball screw system ensures that the equipment maintains a high level of repeatability over extended periods of operation, which is essential for tasks requiring consistent measurements.

Real-World Application: For semiconductor manufacturing, measurements such asinter-layer distancesbetween wafers require extremely high precision. With the use of precision guide rails and ball screw systems, even long-term operation maintains measurement consistency and accuracy, meeting the strict requirements of industrial production.

Conclusion: Stability as the Core Guarantee of Precision

Thestructural design and stabilityof a VMM directly impact its measurement accuracy and operational efficiency. Whether it’s thegranite base,cantilever structure, or theprecision guide rails and ball screw systems, every design element is in place to ensure measurement precision. Only through thoughtful design and material selection can the equipment ensure high efficiency, stability, and accuracy in practical applications.

In the future, as measurement technology continues to evolve, VMMs will become even more intelligent and automated. Thestructural designwill continue to play a key role. Through optimization and stability enhancement, VMMs will not only meet the needs of more complex component measurements but also support intelligent manufacturing and automation in various industries.