Applicable Systems
Dornier Weaving Machine
Symptoms
The Dornier weaving machine displays alarm D008, indicating let-off tension anomaly. The warp let-off system is not maintaining the correct tension, causing tension spikes or sag that affect fabric quality.
Possible Causes
- Let-off servo motor is not responding to the tension setpoint change from the controller
- Warp beam brake is not releasing or applying correctly, causing tension to spike or sag
- Let-off tension sensor has drifted, causing the controller to adjust based on incorrect feedback
Troubleshooting Steps
- Step 1: Check the let-off servo motor response to tension setpoint changes
Motor responds to tension changes within 0.5 seconds with smooth acceleration and deceleration - Step 2: Verify the warp beam brake operation and the brake air pressure or hydraulic pressure
Brake applies and releases correctly and the pressure matches the setpoint value - Step 3: Calibrate or replace the let-off tension sensor
Sensor reading matches a calibrated reference within 5 percent at the setpoint tension
How to Reset
To reset: 1) Repair or replace the let-off servo motor. 2. Repair the beam brake. 3. Replace the tension sensor. 4. Press RESET. 5. Verify stable tension during continuous weaving.
Source: Dornier Weaving Machine Manual, Lindauer Dornier GmbH
Category: Textile