Why do we need to calibrate TRA for laser cutting?

In laser cutting systems, the Tracking Regulation Assembly (TRA) is a critical component that enables dynamic tracking and adjustment of the cutting head. It typically incorporates capacitive or laser sensors to monitor the distance between the nozzle and the workpiece surface in real time, thereby adjusting the cutting head height. The core function of TRA is to maintain stable focus position during cutting, which is particularly crucial for processing three-dimensional curved surfaces or uneven sheet materials.‌

The role of TRA sensors in laser cutting

Height-following control: When the workpiece's shape changes or surface irregularities occur, the TRA sensor automatically detects these variations and adjusts the cutting head's height accordingly, maintaining optimal distance from the workpiece surface to ensure consistent cutting quality.

Collision detection and protection: During rapid positioning of the cutting head, the TRA sensor functions as a collision sensor. When the cutting head collides with the workpiece or other obstacles, it promptly detects the impact and activates the automatic shutdown function. This prevents costly mechanical damage to the cutting head and machine tools, thereby reducing maintenance costs and downtime.

Temperature monitoring: Some TRA sensors can detect the temperature of nozzles and other parts in real time to ensure that the relevant parts work in the appropriate temperature range to ensure a stable capacitance value, thereby achieving accurate height following and stability of the cutting process.

Cutting quality monitoring: By tracking parameters like laser power and cutting speed during the process, TRA sensors provide data-driven support for quality control. This enables operators to promptly detect potential issues such as material overheating or seam widening, allowing timely adjustments to enhance cutting precision and product consistency.

Why calibrate the TRA sensor

Calibrating the TRA sensor is essential to ensure accurate detection data, prevent quality degradation or equipment damage caused by data deviations, and maintain laser cutting stability.

1. Ensuring high tracking accuracy

The core function of the TRA sensor is to control the distance between the cutting head and the workpiece surface. If the sensor is not calibrated, the detected distance may be off from the actual distance, which may cause the laser focus to shift. Focus offset will directly cause problems such as cutting not through, cutting too wide or burning the surface of the workpiece, which seriously affects the cutting accuracy and the quality of the finished product.

2. Maintain the reliability of collision detection

Collision detection function depends on the sensor's accurate identification of force or displacement. After long-term use, the trigger threshold of the sensor may drift, and failure to calibrate may cause it to be insensitive to collisions or trigger incorrectly. Insensitivity may cause the cutting head to collide with the workpiece without stopping the machine, resulting in equipment damage; mis-triggering will frequently interrupt the cutting process and reduce production efficiency.

3. Ensure the effectiveness of auxiliary monitoring parameters. 

Some TRA sensors require monitoring of auxiliary parameters such as temperature and capacitance to ensure stable operation. If the temperature or capacitance detection value deviates due to non-calibration, it will interfere with the judgment of the height following algorithm and lead to unstable cutting process. For example, the inaccurate capacitance value may cause the cutting head to fluctuate up and down frequently on the curved workpiece, and cannot maintain a constant cutting distance.

4. Compensate for aging and environmental effects

The performance of sensors will deteriorate with time and environmental changes. Long-term vibration, dust attachment or temperature and humidity change will lead to the decrease of sensor accuracy. Regular calibration can correct these external factors and aging errors, so that the sensor is always in the best working state.

How to determine if the TRA Sensor needs calibration

To determine whether a TRA sensor requires calibration, the system identifies three key indicators: abnormal cutting performance, device alarm prompts, and scheduled maintenance cycles. If any of these conditions occur, calibration should be prioritized for troubleshooting.

1. Abnormal cutting quality

Cutting quality is the most direct feedback of sensor status. When the following problems occur, calibration should be considered first: cutting is not through or the cutting gap is too wide: the distance between the cutting head and the workpiece deviates from the ideal value, resulting in the wrong laser focus position, which is common in the sensor height detection is not accurate. Burnt or slagged surface of the workpiece: the cutting head is too low, the laser energy is too concentrated, or the position deviation is caused by the lag of the height detection. Poor cutting accuracy of curved or irregular parts: the sensor's response to the workpiece contour is off, and the correct height cannot be adjusted in real time. 

2. The system's alert and prompt indicate clear signals.

Check and calibrate immediately if any of the following conditions occur: The "height tracking anomaly" alarm is triggered when the sensor detects a deviation between the height data and the actual value exceeding the set threshold, causing the system to report an error.

False or false collision detection: The system triggers an alarm and stops without contacting the workpiece (false trigger), or stops without detecting a collision (false non-trigger), indicating a drift in the collision threshold.

Temperature / Capacitance parameter alarm: Some sensors detected abnormal temperature and capacitance values. After troubleshooting hardware issues, the problem was most likely due to invalid calibration data.

3. Determine based on regular maintenance and usage scenarios

Even if there is no obvious abnormality, the following scenarios require mandatory calibration based on regular maintenance and usage scenarios:

When the calibration cycle is reached: According to the equipment manual requirements, mandatory calibration is usually required every 3-6 months or after a certain working hour (such as 1000 hours).

After replacing key components: After replacing cutting head, sensor probe, nozzle ceramic body and other components, the original calibration data is invalid and must be recalibrated.

Significant environmental or material changes: recalibrate for new scenarios when working in high dust and humidity for a long time, or when switching between workpieces with different thicknesses or materials.

What we can do after the TRA sensor failure is detected?

After the TRA sensor failure is detected, there are two solutions:

1. Sent the sensor to the service center for a repair;

2. Buy a new TRA sensor

Raysoar provides the repair service for sensor failure including replacing the body, the thread damage, pin break repair, insulating seat damage, circuit board replacement for the major brands TRA sensor such as Amada, Trumpf, Precitec.

If the repair is not available, or the repair costs is even higher than replacing a new one, the right thing you can do is to replace it, check the sensor type and find the matching products. Raysoar supply most TRA sensors covering the major brands of laser cutting machines in the market.