Fundamentals of CNC Machining Technology and Specifications

Core Definition of CNC Machining (Numerical Control Machining): A precision machining technology that uses digital code (G-code, M-code) as its control core to drive the moving components of a machine tool via a CNC system, thereby achieving the cutting and shaping of parts. Its core technical indicators directly determine machining accuracy and efficiency, and the following key parameters must be met: Repeatability ≤ 0.01 mm, positioning accuracy ≤ 0.005 mm (for high-end equipment), feed rate range 0–10,000 mm/min, and spindle speed range 100–24,000 rpm (high-speed machining equipment can reach 60,000 rpm). Below are the fundamentals of CNC machining technology and specifications in details.

1.1 Core Components and Technical Specifications of CNC Machine Tools

Machine Body: Features a cast iron bed (HT300 material, hardness 180–220 HB) and linear guideways (ball screw model SFU4005, lead 5 mm, precision grade C3). Table dimensions vary by machine type: 400 × 800 mm (vertical milling machine) and 800 × 1500 mm (horizontal machining center). The load capacity ranges from 500 to 5000 kg to prevent bed deformation during machining.
CNC System: Mainstream models include FANUC 0i-MF, SIEMENS 828D, and Huazhong HNC-210A. Core functions include interpolation (linear, circular, and helical), tool compensation (length compensation G43/G44, radius compensation G41/G42), program storage capacity ≥1000KB, support for USB/network program transfer, and response time ≤10ms.
Servo System: Equipped with AC servo motors (power 1.5–30 kW) and FANUC MR-J4-200A servo drives. The system employs closed-loop control with feed acceleration ≤5 m/s² and positioning accuracy ≤0.003 mm, ensuring precise motion trajectories.
Measurement Devices: Equipped with a linear encoder (resolution 0.001 mm) and a rotary encoder (pulse equivalent 0.0001 mm), providing real-time feedback of motion parameters to achieve closed-loop error compensation and prevent accuracy deviations caused by mechanical backlash (lead screw backlash ≤ 0.002 mm).
Control Language: Primarily ISO standard G-code. Common manual programming commands include: G00 (rapid positioning), G01 (linear feed), G02/G03 (arc feed), M03 (spindle clockwise rotation), M08 (coolant on), and M30 (program end).

1.2 CNC Machine Tool Classification and Applicable Scenarios

Precisely Matching Machining Requirements

CNC Lathe (CK6140): Spindle through-hole diameter 40mm, maximum machining diameter 400mm, maximum machining length 1000mm. Suitable for turning shafts and sleeves, such as stepped shafts and threaded shafts. Cutting speed 80-120m/min.

CNC Milling Machine (XK7132): Table travel 320×1250×300mm, spindle speed 100-3000rpm. Suitable for machining planes, grooves, and steps. Uses end mills (Φ16-Φ25mm), feed rate 0.1-0.3mm/r.

CNC Machining Center (VMC850): Vertical structure, spindle speed 8000rpm, tool magazine capacity 24 tools. Supports integrated milling, drilling, and tapping machining. Positioning accuracy ±0.005mm. Suitable for batch machining of complex parts.

Five-axis linkage CNC machine tool (DMU 50 type): swing angle ±120°, spindle speed 12000rpm, positioning accuracy 0.002mm, suitable for machining complex curved surfaces of aero-engine blades and molds, avoiding multiple clamping errors.