What are the common malfunctions in CNC lathe operation?

I. Common Mechanical Faults

1. Spindle Component Faults

Decreased Accuracy: Long-term use leads to spindle bearing wear and increased clearance; prolonged high-speed spindle operation causes thermal deformation, affecting machining accuracy, manifesting as dimensional deviations and accompanied by harsh, irregular noises.

Spindle Not Rotating/Abnormal Speed: Electrical causes are often due to motor, inverter, or wiring connection problems; mechanical causes are often due to broken drive belts or loose couplings, manifesting as the spindle completely stopping, or unstable speed, failing to reach the maximum set speed.

2. Feed System Faults

Crawling Phenomenon: Poor guide rail lubrication leads to unstable friction, or inappropriate lead screw preload (too high for excessive friction, too low for clearance), manifesting as uneven and jerky feed motion; in severe cases, the control system triggers an overload alarm, stopping the feed.

Tool Loosening/Abnormal Tool Changing: Wear on the tool turret guide rail or damage and detachment of the trapezoidal lead screw balls can cause tool changing jams, tool loosening, affecting machining accuracy, and even preventing normal tool changing.

3. Other Main Unit Faults
Excessive transmission noise and high operating resistance (due to bearing wear, insufficient lubrication, and aging transmission belts); insufficient hydraulic chuck pressure leading to insecure workpiece clamping; oil and air leaks in pipelines, etc.

II. Common Electrical and Servo System Faults

1. Servo System Faults: Abnormal noise from the servo motor, failure to operate, and out-of-tolerance positional accuracy are mostly caused by loose motor wiring, abnormal encoder signals, or incorrect servo parameter settings.

2. Power Module Faults: Inability to power on, power indicator light not illuminated, and abnormal output voltage are mostly caused by loose input/output wiring, unstable voltage, or hardware damage to the module itself.

3. Circuit and Component Faults: Loose wiring, worn and short-circuited cables, and damage to components such as relays, contactors, and emergency stop switches can easily lead to power outages and malfunctions.

III. Common CNC Control System Faults

1. Abnormal System Display: White screen upon power-on and blurry text are mostly caused by incorrect CMOS resolution settings or improper screen brightness adjustment; adjusting parameters will resolve the issue. System failure to start and unresponsive operation panel are mostly due to power supply failures or hardware damage to the control board.

2. Parameter Loss/Incorrection: Backup battery failure (prone to this due to prolonged machine tool inactivity), misoperation, or sudden power outages can cause CNC system parameters to be lost or modified, resulting in abnormal program operation and loss of machining accuracy control.

3. Program Operation Failure: Errors in the machining program or communication transmission failures can cause the program to fail to run, or to suddenly interrupt operation and trigger alarms.

IV. Common Machining Failures

1. Collision/Machine Collision Accidents: Incorrect coordinate value input during programming, incorrect tool number input, incorrect tool change point setting, or mechanical failures in the servo drive system leading to asynchronous movement can all cause machine collisions, which can severely damage the tool, workpiece, or even the machine tool guide rail and spindle.

2. Excessive Machining Dimension/Accuracy Errors: Uncompensated tool wear, tool setting errors, excessive lead screw and guide rail clearance, and thermal deformation can lead to out-of-tolerance part dimensional errors, which are often irregular and difficult to control.

3. Vibration/Poor Surface Roughness: Unstable machine tool placement, damaged cutting edge, and unreasonable cutting parameters can cause vibration during machining, resulting in ripples on the workpiece surface and substandard roughness.