Detailed Explanation of The Problem of Laser Head Hitting The Plate of Laser Cutting Machine: Causes, Consequences And Solutions

Detailed explanation of the problem of laser head hitting the plate of laser cutting machine: causes, consequences and solutions

I. Problem definition: What is laser head hitting the plate?

Laser head hitting the plate refers to the phenomenon that the cutting head (including focusing mirror, nozzle and other components) accidentally comes into physical contact with the processing material or workbench during the operation of the laser cutting machine. This phenomenon may cause equipment damage, reduced cutting quality, and even cause safety hazards.

II. The main reason for the laser head hitting the plate

Parameter setting error

Focus position deviation: The focus position is not correctly adjusted according to the material thickness, resulting in the cutting head height being too low.

Cutting speed is too fast: Inertia causes the Z axis to lose control during high-speed movement, causing a collision.

Material or table problem

Uneven material: The plate is warped, the surface is raised, or the residual waste is not cleaned.

Loose fixture: The material is not fixed stably and shifts during processing.

Equipment hardware failure

Height control failure: The capacitive height control (Height Control) sensor fails and cannot feedback the height data in real time.

Servo motor/guide rail failure: The Z axis motion accuracy is lost, resulting in positioning errors.

Operational error

Manual operation error: The equipment is not turned off during debugging or material change, and manual movement causes collision.

Program path error: CAD drawings are not simulated and verified after import, and the path contains illegal jumps.

III. Consequences of laser head hitting the board

Equipment damage

Nozzle deformation or rupture: Direct contact with the plate causes nozzle damage, affecting the uniformity of gas injection.

Focusing lens scratches: Lens contamination or scratches will reduce the efficiency of laser energy transmission and lead to reduced cutting quality.

Z-axis mechanical structure damage: The guide rail and lead screw are deformed due to impact force, affecting long-term accuracy.

Production interruption

The equipment needs to be shut down for maintenance, and it takes about 2-4 hours to replace accessories (depending on the degree of damage).

Safety hazards

Collision may cause sparks or equipment short circuits, increasing the risk of fire.

IV. Emergency treatment and repair steps

Stop immediately

Press the emergency stop button to cut off the power supply to avoid secondary damage.

Check damaged parts

Nozzle: Observe whether it is deformed and replace with a new nozzle (reference model: 1.5mm/2.0mm aperture).

Lens: Clean with dust-free cloth dipped in anhydrous ethanol. If the scratches are serious, replace it (cost is about ￥200-800/piece).

Guide rail and lead screw: Manually move the Z axis to check whether it is stuck. If necessary, contact the manufacturer for calibration.

Troubleshooting

Height adjuster test: Use a metal plate to simulate the material and observe whether the sensor feedback is sensitive.

Program verification: Simulate the cutting path in the software and check whether there are abnormal jumps.

V. Measures to prevent the laser head from hitting the board

Parameter optimization

Set safe height: In the cutting path, the Z axis lifting height must be higher than the maximum protrusion of the material (recommended ≥5mm).

Reduce the idle speed: The Z axis idle speed is controlled at 20-30m/min to avoid inertial loss of control.

Equipment maintenance and calibration

Daily inspection: Test the height adjuster sensitivity before starting the machine, and clean the lens and nozzle.

Monthly maintenance: lubricate the Z-axis guide rail and check the servo motor encoder signal.

Material and tooling management

Plate pretreatment: use a leveling machine to eliminate material warping, and clean surface rust and residue before cutting.

Strengthen fixture fixation: use magnetic fixtures or vacuum adsorption tables to ensure that the material is flat.

Operation specification training

Simulation verification: use software (such as LightBurn) to simulate the path before cutting to avoid collision risks.

Manual operation specifications: switch to "manual mode" during debugging and wear protective glasses.

VI. Case sharing: Solution to the plate collision problem in a sheet metal factory

Problem description: A factory caused the laser head to collide and the nozzle was damaged 3 times/month due to the warping of the edge of the stainless steel plate.

Solution:

Install an automatic plate leveling machine to ensure that the flatness error of the incoming material is less than 0.5mm.

Upgrade the capacitor height controller to the dynamic response mode and increase the detection frequency to 1000Hz.

Train operators to perform "Z-axis zero calibration" before starting the machine every day.

Effect: The collision frequency is reduced to 0 times/month, saving ￥50,000 in maintenance costs per year.

VII. Recommended technology upgrades

Intelligent anti-collision system

Some high-end models (such as TRUMPF TruLaser 5030) are equipped with infrared obstacle avoidance sensors that can detect obstacles in real time and automatically shut down.

Capacitive height controller

Supports dynamic height tracking (such as Precitec ProCutter), adapts to material surface fluctuations, and has an accuracy of ±0.01mm.

Remote monitoring function

Real-time monitoring of equipment status through the Internet of Things (IoT), and sends mobile phone alerts when abnormalities occur.

VIII. Summary

Laser head hitting the plate is a common problem in laser cutting, but it can be effectively avoided through parameter optimization, equipment maintenance and standardized operation. Investing in intelligent anti-collision technology and employee training can not only reduce equipment wear, but also improve production safety and efficiency.