Function of Linear Scales in CNC Machining Centers
2026-02-11
Linear scales (also known as linear optical scales) are key components for achieving high-precision control in CNC machining centers. Their primary function is to provide high-precision linear position feedback for full closed-loop control, which greatly improves the positioning accuracy, repeatability, and machining accuracy of the machine tool.The core functions and advantages are explained in detail below:
1. Realize True Full Closed-Loop ControlStandard machining centers typically use rotary encoders mounted on the servo motor shaft for position feedback, known as semi-closed-loop control.This method only measures the rotation angle of the motor and converts it into linear displacement of the worktable through transmission mechanisms such as ball screws.However, the transmission chain (screws, nuts, couplings, bearings, etc.) suffers from backlash, elastic deformation, thermal expansion, wear, and pitch errors. The encoder cannot detect the deviation between the actual worktable position and the theoretical position caused by these factors.A linear scale is installed directly between the worktable / headstock and the machine bed, measuring the actual linear displacement in real time. This true position signal is fed back to the CNC system.The CNC system compares the actual position from the linear scale with the target position from the program, calculates the error, and sends correction commands to the servo drive. The drive adjusts the motor until the actual position matches the target, forming a complete closed-loop process:Command → Execution → Actual Measurement → Correction → Command.
2. Eliminate Transmission Errors and Improve Precision
This is the most important value of linear scales.By directly measuring the real position of the final moving parts, the linear scale system can detect and compensate for various transmission errors in real time:Pitch errors of the ball screwThermal elongation of the screw caused by machining heatBacklash from wear of the screw and nutReverse backlash during direction changesElastic deformation from cutting force and accelerationStraightness and parallelism errors of linear guidesWith such compensation, the machine positioning accuracy can stably reach the micron (μm) or even sub-micron level.
3. Improve Machining Accuracy and Surface QualityHigher position control accuracy directly improves the dimensional accuracy, form accuracy, and positional accuracy of machined parts.More precise position control also helps achieve better surface finish.
4. Enhance Dynamic PerformanceAlthough linear scales do not directly increase speed, high-precision real-time feedback allows the system to accurately track the commanded path during high-speed feeding, reducing following errors and achieving better dynamic performance while maintaining accuracy.
5. Maintain Long-Term Precision and Reduce Maintenance CostsEven if transmission parts such as ball screws gradually wear over time, the linear scale system can continuously detect and compensate for the resulting errors. This allows the machine to maintain high precision for a longer period and reduces strict requirements for the precision of consumable components.
SummaryThe core function of a linear scale is to bypass intermediate transmission links, directly obtain the real position of moving parts, and achieve high-precision full closed-loop control.It is an indispensable component for high-end machining centers to perform ultra-precise, highly stable, and long-lasting machining.
View More
Differences Between CNC Milling Machine and Machining Center
2026-01-27
Both CNC milling machines and machining centers are commonly used CNC machine tools in modern manufacturing, but there are significant differences between them. This article will elaborate on their key distinctions to help you make informed choices based on actual processing needs and production conditions.
1. Tool Magazine and Automatic Tool Changer
CNC milling machine: Generally, it does not have a tool magazine, and manual tool change is required during the machining process. This means that when processing complex parts, multiple clampings and tool changes are needed, which affects machining efficiency and precision.
Machining center: Equipped with a tool magazine and an automatic tool changer (ATC), it can automatically change tools during the machining process. This enables the machining center to complete multiple machining processes (such as milling, drilling, tapping, etc.) in a single clamping, greatly improving production efficiency and machining precision.
2. Axis Number and Linkage Capability
CNC milling machine: Mainly used for milling operations, it can process planes, grooves, gear teeth, threads, etc. It is suitable for relatively simple machining tasks.
Machining center: Integrates multiple functions of CNC milling machines, CNC boring machines, CNC drilling machines, etc. It can complete various machining tasks such as drilling, tapping, reaming, grooving, etc., and is suitable for complex parts that require multiple machining processes.
3. Production Efficiency
CNC milling machine: CNC milling machines may adopt an open or semi-open design.
Machining center: Usually adopts a fully enclosed design, providing better safety protection and machining environment. It prevents iron chips and cutting fluid from splashing, thus protecting operators.
In summary, CNC milling machines and machining centers have significant differences in terms of tool magazine and automatic tool changer, axis number and linkage capability, functions and application scope, production efficiency, as well as appearance and protection design. The choice of which equipment to use depends on specific processing requirements and production conditions.
View More
What are the advantages of gantry machining centers?
2026-01-10
1. High Precision and High EfficiencyGantry machining centers offer extremely high machining precision. Supporting multi-axis simultaneous cutting, they are suitable for batch and mass production of large workpieces, including planar and inclined surfaces. Both machining precision and production efficiency are among the highest in the industry. The symmetrical portal frame structure (double columns + top beam + crossbeam) provides outstanding load-bearing and torsional resistance, capable of withstanding the large cutting forces and torques of heavy-duty cutting, reducing machining vibration and deformation, ensuring long-term precision stability, and extending the lifespan of tools and equipment.
2. Large Machining Range and Load CapacityX/Y/Z axis travel can reach several meters, and the worktable load capacity can reach tens of tons. Large/ultra-large workpieces can be machined in a single setup, avoiding the repetitive positioning and accumulated errors of segmented machining. This makes them particularly suitable for the overall machining of ship sections, wind turbine blades, and aerospace structural components.
3. High Degree of AutomationCNC gantry machining centers are equipped with a tool magazine as standard, featuring automatic tool changing functionality. By equipping the tool magazine with tools for different purposes, the spindle tool can be changed during a single workpiece clamping using an automatic tool changer, enabling various machining processes such as milling, drilling, and boring, significantly improving machining efficiency.
4. Wide Range of Applications
Gantry machining centers and CNC milling machines are suitable for multiple industries, including automotive manufacturing, aerospace, energy, machinery manufacturing, electronics, medical equipment, and mold manufacturing. The equipment can process various complex curved surfaces and irregularly shaped parts, fully meeting the personalized machining needs of different industries and customers. It can process metals/non-metals/composite materials such as titanium alloys, stainless steel, and carbon fiber. Its modular design allows for quick change of attachment heads, adapting to harsh working conditions such as high-temperature alloy cutting.
View More
Year-end clearance sale, limited-time special offer!!
2025-12-31
New Year's Day 2026: Bid farewell to the old and usher in the new; upgrade your intelligent manufacturing! High-rigidity machining centers are ready to go—enabling efficient forming of complex workpieces and faster order delivery!
View More
How to Choose a Machining Center for Large-Scale Complex Parts?
2025-12-23
Dual-station horizontal machining centers are high-efficiency, high-precision CNC machine tools widely used for mass production of complex parts.
1. Basic Structure and Features
Horizontal Layout: The spindle is horizontally arranged, and the workpiece is mounted on a horizontal worktable, suitable for multi-face machining of box-type and large parts (such as engine blocks, gearbox housings, etc.). Dual-station Design: Equipped with two independent worktables (or one rotary dual-station table), enabling simultaneous machining and loading/unloading, significantly reducing non-cutting time and improving efficiency. Automation Integration: Often used in conjunction with automatic tool changers (ATC) and pallet exchange systems (APC) to support unmanned production.
2. Core AdvantagesHigh Efficiency: While one station is machining, the other station can clamp the workpiece, enabling continuous production.High Precision: Utilizing a rigid structural design and thermal compensation technology, positioning accuracy can reach ±0.005mm. Complex Machining Capabilities: Supports four-axis/five-axis linkage, capable of performing composite machining such as milling, drilling, tapping, and boring.
3. Typical ConfigurationSpindle: High-torque electric spindle (speed range typically 50-12,000 rpm, geared transmission optional)Table: Dual-pallet exchange system or rotary indexing table (load capacity up to several tons)Control System: High-end CNC systems such as Fanuc, Siemens, or MitsubishiTool Magazine: Chain-type tool magazine (capacity 20-120 tools), supporting high-speed tool changing (tool change time 1-3 seconds).
4. Application AreasAutomotive Industry: Batch machining of engine blocks and crankcases.Aerospace: High-precision manufacturing of aircraft structural components and landing gear.Energy Equipment: Multi-faceted machining of wind turbine gearboxes and hydraulic valve bodies.
5. Selection ConsiderationsWorkpiece Size and Weight: Matching table size and load capacity.Machining Accuracy Requirements: Focusing on machine tool repeatability and dynamic performance.
View More