In achieving overall high-quality Sheet Metal Laser Cutting results, speed and efficiency-wise, people now prefer modern cutting processes over traditional cutting methods, such as sawing, drilling, turning, or milling. Aside from this, the advanced techniques come with low costs, unique shapes and precise design results, as well as a small kerf width.
And one of these in-demand cutting techniques used by various steel and home workshops is sheet metal laser cutting. This is a thermal fabrication method of cutting sheet parts through a great force generated by a laser beam.
And no matter how effective the cutting process is, there are inevitable factors that contribute to specific issues it will encounter. This article will discuss some common problems with common solutions in laser cutting to guarantee customers first-rate results.
Sheet Metal Laser Cutting: Background
In 1965, fabricators used a laser cutter to drill diamond dies holes. Two years later, Western Electric Engineering Research Center launched the first laser-assisted oxygen jet cutter specifically made for metals. This was widely used in the aerospace industry, especially for cutting titanium. Its precision is due to the sheet metal laser cutter.
Along with this is a CO2 laser cutter invention. However, it was not ideal for cutting rigid materials, like alloys and metals, only for non-metals (such as textiles).
Sheet metal laser cutting, from the name itself, uses a high-powered “laser” to cut through a variety of materials, unlike other cutting methods that use blades. When the laser beam is correctly positioned to the desired material surface to cut, it strikes the part, cutting it efficiently.
A sheet laser device can cut through ferrous and non-ferrous materials, such as carbon steel, aluminium, zinc, and tool steel. It can also cut 3D materials, like profiles and tubes. The machine consists of the following components: power supply, laser source, focusing lens, mirrors, nozzle, pressurised gas, and a workpiece table.
How Does a Laser Cutting Machine Work?
Laser beams can create cuts and incisions. But for them to achieve speed, accuracy, and efficient results, laser power and material thickness will have a role to play. Normally, the laser type used for the cutting process is CO2 based, with around 1,000 to 2,000 power watts. As for materials that require a high-powered laser—like aluminium and copper alloys—manufacturers use Nd and Nd-YAG lasers.
The process starts with generating a laser beam through a stimulated lasing material. The stimulation is done through several electrical discharges within a container. A partial mirror causes the beam to be reflected during this process until it gains sufficient energy. This high-energy beam then escapes as monochromatic coherent light.
Through several mirrors (fibre optics) and the cutting head, the beam is directed, with precise focal length, at the targeted piece to cut. Some shops conduct the process while the workpiece moves while the cutting head remains stationary. For others, it is the opposite. Regardless of the system used, the laser beam still efficiently etches intricate shapes and bores tiny holes in the material.
Additionally, pressurised gas either eliminates, burns, or melts the molten metal parts during the cutting process. This jet gas leaves a top-quality cut edge, with little to no burrs.
Common Laser Cutting Issues and Ways to Address Them
A machine is like a human being; even with its top-quality performance unmatched with manual strength, it sometimes goes through errors. If not addressed immediately, this can highly affect your laser cutting machine, resulting in substandard cutting results.
Some of the factors that contribute to these issues are the following:
- Cutting speed
- Sheet type
- Heat elements
- Lens contamination
- Gas pressure
- Nozzle quality
- Focus position
- Machine handling
- Lack of maintenance
Below are the common issues associated with sheet metal laser cutting:
Edge burrs
The ideal cutting result fabricators aim during a laser cutting method is always a material’s burr-free edge. However, there are times that burrs remain. The molten metal that quickly solidifies before it is properly melted or eliminated causes these burrs. The laser focus position, insufficient output power, or unstable guide movement are some of the known reasons for burrs, too.
Tip: First, the operators must be knowledgeable about the interaction of the cutting beam, pressurised assist gas, and workpiece. The technicians (for modern systems, the machine itself) must adjust the cutting parameters or determine the beam’s focal point. Another way to avoid the issue is completely restarting the device.
Deformed shape and uneven edges
Another issue in laser cutting is the deformed cut metal produced after the cutting process. The uneven cutting mostly happens to carbon steel. Some possible factors that result in these cutting results are the raw materials’ reflective and metal properties. This likely happens to thin metal plates cut with excessive heating. Additionally, less cutting area or focal point error may also contribute to the issue.
Tip: The fabricator should recheck if the laser cutting machine is set correctly. This can also be avoided by controlling the ideal heating requirements for that specific material based on its thickness. Also, remember that tiny shapes will require speeding up the laser. This will help prevent deformities in form and a thermal runaway or blowout.
To avoid burning, use gas-assisted technology. In addition, ensure that the distance between the main shaft’s centre and the main shaft on the ground is minimised to regulate the heat properly. Lastly, improve your machine’s lathe unit (used for shaping the material).
The laser will not cut through the material
An insufficient cutting depth on the material is mainly caused by poor machine maintenance or improper machine handling. Additionally, it also happens due to reduced laser power, ageing lamp tube, damaged focusing lens, and unstable voltage.
Tip: To avoid this, you should adjust the focal point of the machine and the depth, recheck output power, or slow down the engraving speed. The latter also holds true when using the soft puncture (or pulse perforation) instead of blasting perforation. We also provide Sheet Metal Engraving services to our valued client.
As for your focus lens, reflector, and fibre optics, ensure that they are free from any contamination. You should also replace the laser tube, heighten the voltage regulator, and increase the auxiliary gas pressure.
Defective machine components
Among the laser cutting problems, perhaps this is the most common, not to mention the root cause of all the issues discussed above. Your laser cutting equipment will encounter complications, especially with regular use. With these complications comes cutting inaccuracies—and naturally, unsatisfied clients.
Defective components mostly include instability of workpiece table, insufficient power output, broken origin switch and motor wire, loose screws, inaccurate laser tube connection—the list can go on.
Tip: Your machine is the core of your sheet metal laser cutting method. To ensure that it is operating at peak performance, make it a habit to conduct a weekly or daily checkup on its components. A minor malfunction can create destructive effects on your machine’s other parts.
In conclusion, since sheet metal laser cutting is a complex and sensitive method, achieving uniformity on your desired design and cut results is your goal. This is why, as a manufacturer or machine owner, you must address any issues encountered by the device to prevent significant consequences.
Related Post: Water Jet Cutting Service: All You Need to Know
Get Desired Cutting Results with Special Build
Expert technicians ideally handle persistent laser device issues. To avoid sheet metal laser cutting issues, work with Special Build. Together with the expertise and creativity of our team of qualified craftsmen, plus our high-tech machinery, we deliver only the best cutting results.
Special Build will not settle for anything less than high-quality services, so we commit to ensuring our machines operate at peak performance. We ensure that this goes hand in hand with our technicians’ proper handling and maintenance.
So, what are you waiting for? Coordinate with and trust our cutting experts today! Learn more about our laser cutting services by calling +61 2 9616 7444.