Metal laser cutting machines are a crucial tool in the mechanical metal processing and manufacturing industry and are commonly used to replace traditional cutting equipment. However, improper operation or lack of maintenance can lead to various problems with this precision equipment.
One common issue during the cutting process is the phenomenon of not cutting through.
To address this issue, it’s important to understand the causes and find suitable solutions.
In the following, I will introduce the causes and solutions for the problem of not cutting through with laser.

I. Understanding Laser Cutting Principles
Laser cutting is a non-contact process that involves using a focused, high-power laser beam to vaporize, burn, or melt the selected material, resulting in a precise cut or engraving. The process involves directing the laser beam to follow a specific path, which is usually pre-programmed using computer software, to make the necessary incisions.
There are three primary types of lasers commonly used in laser cutting:
- CO₂ lasers are highly versatile and can cut a wide variety of materials ranging from wood, plastics, to fabrics. CO2 lasers function by exciting carbon dioxide gas using electrical energy to produce a laser beam.
- Nd lasers use neodymium-doped crystals to produce a high-powered laser beam. These lasers are capable of cutting thicker materials and are often used in industrial settings for metal cutting.
- Fiber lasers are a type of solid-state laser that utilize optical fibers infused with rare-earth elements. They are known for their high reliability and efficiency, making them ideal for cutting metals.
There are several key factors that can determine the effectiveness and quality of a laser cut:
- Laser power: Higher power output contributes to a faster cutting speed and the ability to cut through thicker materials.
- Focal length: The longer the focal length, the deeper and wider the laser’s focus area, which can affect the precision and quality of the cut.
- Material type and thickness: Some materials require higher power levels or different types of lasers to achieve optimal cutting results.
When cutting through materials, the speed at which the laser moves across the material is important to consider. If the laser moves too slowly, it may cause excessive burning or melting that could result in an imprecise cut. Conversely, if the laser moves too quickly, it may not have enough power to penetrate the material effectively.
Proper lens selection, based on the type of material being cut and the desired cutting quality, is crucial for an effective laser cutting process. There are three common types of lenses used in laser cutting:
- Short-focus lenses generally provide higher precision but require closer proximity to the material.
- Long-focus lenses are suited for cutting thicker materials but may sacrifice some precision.
- Medium-focus lenses are a versatile option that can accommodate a range of materials and thicknesses.
By understanding the principles of laser cutting and adjusting these factors accordingly, users can optimize their cutting process for various materials and desired results.
II. Causes for Laser Not Cutting Through
Laser cutting is a complex process and can often result in rough incisions or incomplete cuts. There are various reasons why this can occur, including a reduced laser power or aging lamp tube, which leads to insufficient laser beam energy.
Other reasons can include cutting at too fast a speed, damage to the focusing lens, poor focusing, incorrect light path, and unstable voltage.
Other factors that can cause rough incisions or incomplete cuts include the material itself, insufficient auxiliary gas pressure, dirty cooling system water, and poor heat dissipation.
It is important to take the issue of incomplete laser cuts seriously and work to identify and address the root causes in order to improve production efficiency and ensure high-quality laser cutting.

The following is a list of six reasons for a laser cutting failure.
- Decreased laser power: Over time, the laser power of a fiber laser cutting machine can gradually decrease, causing a decline in cutting ability and leading to incomplete cuts.
- Optical element pollution: Optical elements like focus lenses and reflectors are susceptible to residue build-up from long-term exposure to poor working conditions, which can reduce laser power and lead to incomplete cuts.
- Poor light spot debugging: The light spot of a fiber laser cutting machine is crucial to cutting quality, and if it is not properly debugged, it can result in a lack of clean cuts.
- Excessive cutting speed: If the cutting speed is too fast, it can lead to missed cuts and result in incomplete cuts.
- Insufficient auxiliary gas pressure: Auxiliary gas helps blow away residue during cutting, and if the air pressure is not enough, it can result in clogged cuts.
- Exceeding plate thickness limits: Different fiber laser cutting machines have different cutting thickness ranges, and if the thickness of the processed plate exceeds the range, it can result in a lack of ideal cutting, including incomplete cuts.

III. Solutions for Laser Not Cutting Through
To address the issue of declining laser power and low current, it is recommended to replace the laser tube and use a larger voltage regulator to increase the laser current output and enhance the output power.
In order to avoid incomplete cuts, it is important to reduce the cutting speed appropriately and keep the optical elements such as the mirrors and focus lenses clean and free from contamination. This may involve timely cleaning or replacement of the lenses.
If there is an issue with the light path, readjust it and adjust the focal length until the laser beam creates a circular spot on the paper.
For cutting materials such as copper and aluminum, which have a high reflection rate, it may be beneficial to polish the surface or apply light-absorbing material in advance.
Regular maintenance, such as cleaning the foreign materials from the nozzle and increasing the pressure of the auxiliary gas, as well as replacing the distilled water in the cooling system in a timely manner, can also help improve the cutting quality and reduce the risk of incomplete cuts.
These measures can effectively solve the problem of the sample not cutting through, and we hope they help you. If you encounter issues that cannot be resolved on your own, it is important to promptly inform your supplier so that professional after-sales personnel can perform further investigation, examination, and maintenance.
IV. Maintenance of Fiber Laser Cutting Machine
Use a vacuum cleaner to remove dust and dirt from the machine once a week and make sure to keep all electrical cabinets closed to prevent dust buildup.
Regularly check the tension of the steel belt on the fiber laser cutting machine. Loose belts can cause operational problems and even pose a safety risk. Although it may seem like a small detail, it is still important to keep the belt tight.
Inspect the straightness of the laser cutting machine’s track and the machine’s verticality every six months and perform timely maintenance and debugging if any issues arise. Neglecting these checks can result in poor cutting quality and increased error, which affects the overall cutting quality.
The double focal length laser cutting head is a vulnerable component that may become damaged over time with prolonged use.
Regularly clean the guide rails of the optical fiber laser cutting machine to remove any dust or debris and ensure normal operation. Wipe down the rack frequently and add lubricating oil to keep it free of debris. Clean and lubricate the guide rail and motor regularly to improve the machine’s movement and cutting accuracy, ultimately leading to improved cut product quality.
Frequently Asked Questions
Why is my laser cutter struggling to cut through materials?
There could be various reasons for a laser cutter not cutting through materials properly. It could be due to misaligned mirrors, a dirty lens, incorrect cutting parameters, or insufficient power. To address this issue, check the alignment of the mirrors, clean the lens, review the settings, and ensure that the power supply is providing adequate energy.
What could be causing insufficient power in my CO2 laser cutter?
Insufficient power in a CO2 laser cutter can be caused by a degraded laser tube, issues with the power supply, incorrect power settings, or faulty wiring. To resolve this issue, inspect the tube and replace it if necessary, ensure the power supply is functioning correctly, check the power settings, and, if needed, fix any wiring problems.
How do I troubleshoot my laser cutter not cutting through wood?
When a laser cutter does not cut through wood effectively, it may be due to issues such as insufficient power, incorrect settings, or poor focus. To troubleshoot this problem, ensure that the power is adequate, adjust the settings according to the type and thickness of the wood, and correctly focus the laser.
What are common issues to check when a K40 laser doesn’t cut through?
A K40 laser not cutting through could be due to misaligned or dirty mirrors, power supply problems, or poor laser focus. To address these issues, align and clean the mirrors, ensure the power supply is functioning correctly, and adjust the laser focus.
Why is my Epilog laser having trouble making complete cuts?
An Epilog laser might have difficulty making complete cuts if there are issues with the lens or mirrors, incorrect settings, or insufficient power. To resolve these issues, clean and align the lens and mirrors, adjust the settings accordingly, and check the power supply to ensure adequate energy is being provided.
How can I resolve my Lightburn laser’s inability to cut effectively?
To enhance the cutting ability of a Lightburn laser, ensure that the proper settings are used for the material being cut, check the power supply to ensure efficient operation, and clean the lens and mirrors. Additionally, make sure that the laser is correctly focused and aligned.
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