Advantages and Disadvantages of Laser Cutting | Xometry

The laser cutting process uses a tightly focused high-energy light/radiation laser beam to create rapid, high-temperature-gradient heating of a single, small-diameter spot. This triggers rapid melting/vaporization of the target material, allowing the spot to travel down through the material thickness rapidly and precisely. 

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The hot spot is blasted with gas, blowing away the melted/vaporized material. This process exposes the cut bottom to allow renewed melting and localized cooling, enabling the cut to proceed. For lighter and more reactive metals, the gas assist uses nitrogen to minimize oxidation. Alternatively, for steel, oxygen assistance accelerates the cut process by locally oxidizing material to assist in slag clearance and reduce the reattachment of melted/cut material.

Laser cutting machines are built in a variety of formats. The most common type keeps the workpiece stationary while laser optics (mirrors) move in both the X and Y axes. Alternatively, a “fixed optic” format keeps the laser head stationary and the workpiece moves. A third option is a hybrid of the two previous methods. All methods execute 2D and 2.5D G-code patterns using a computer-controlled programming system to deliver fully automated, complex cutting paths. Figure 1 is an example of a laser cutting process:

Laser cutting advantages include: high precision, no material contamination, high speed, unlimited 2D complexity, a wide variety of materials, and a wide variety of applications and industries.

High Precision

The narrowness of the energy beam and the precision with which the material and/or the laser optics can be moved ensures extremely high cutting quality. Laser cutting allows the execution of intricate designs that can be cut at high feed rates, even in difficult or fragile material substrates.

No Material Contamination

Traditional rotary cutter processing of materials requires coolants to be applied. The coolant can contaminate the cut parts, which must then be de-greased. Grinding processes may also require coolant/lubricant to be applied. The ablation of the grinding wheel, a natural part of the process, leaves carbide granules that are a hazard in many products. Similarly, water cutting leaves garnet residues. Laser cutting involves only energy and gases and poses no risk of material contamination of the resulting parts.

High Speed

Few production methods can come close in processing speed to laser cutting. The ability to cut a 40 mm steel sheet using a 12 kW oxygen-assisted laser provides speeds some 10x faster than a bandsaw and 50–100 times faster than wire cutting.

Unlimited 2D Complexity

Laser cutting allows intricacy through the nature of the G-code movement control method of positioning and the small size of the applied energy hot spot. Features that are only weakly attached to the main body are cut without any application of force, so the process is essentially limited by material properties, rather than process capabilities.

Variety of Materials

Laser cutting is a flexible technology that can be adapted to cut widely different materials efficiently, including: acrylic and other polymers, stainless steel, mild steel, titanium, hastelloy, and tungsten. This versatility is increasing as technology develops. For example, dual frequency lasers can be applied to cut carbon fiber reinforced composites—one frequency for the fiber, one for the bonding agent.

Variety of Applications and Industries

Laser cutting finds application in many manufacturing industries because of the combination of versatility, high processing speeds, and precision. Sheet materials are key to production across most manufacturing industries. Applications of laser cutting across industries include: airframes, ships, medical implants, electronics, prototyping, and mass production.

Laser Cutting Disadvantages

Laser cutting disadvantages include: limitations on material thickness, harmful gases and fumes, high energy consumption, and upfront costs.

Limitation on Material Thickness

Most laser cutting machines sit in the <6 kW range. Their cut depth is limited to ~12 mm in metal thickness—and they accomplish that only slowly (~10 mm/s). It requires the largest and most powerful machines to reach the practical limits of cutting. However, similar limits apply to waterjet and wire erosion cutting. All three processes perform these deeper cuts faster than can otherwise be achieved.

Harmful Gases and Fumes

While many materials—particularly metals—do not produce harmful gases in the cutting process, many polymers and some metals do. For example, PTFE and various fluoropolymers produce phosgene gas (which is incompatible with human environments) when heated to high temperatures. These materials require controlled atmosphere processing.

High Energy Consumption

Laser cutting machines have a higher energy consumption rate than other cutting tools. A 3-axis CNC machine cutting out 40 mm steel plate blanks will consume around 1/10th of the power of a laser cutting machine extracting the same part. However, if the processing time is 1 minute on the laser cutter and 20 minutes on the CNC, the net power usage is 2:1 in favor of the laser cutter. Each part will have a different profile in this regard, but the differentials are rarely simple to analyze.

The alternatives to laser cutting are wire cutting, plasma cutting, waterjet cutting, and CNC machining.

Plasma Cutting

Plasma cutting is similar to electrical discharge machining (EDM) in that it erodes material by applying an arc to ablate the substrate. However, the arc is conducted from an electrode on a superheated gas plasma stream that directs the arc and blasts out the molten material from the cut. Plasma cutting and laser cutting are similar in that both are capable of cutting metal parts. Additionally, plasma cutting is suited to heavy materials and relatively coarse processing, for example, preparing heavy steel components for architectural and ship projects. It is a much less clean process and generally requires significant post-cut cleanup to make presentable parts, unlike laser cutting.

Waterjet Cutting

Waterjet cutting is typically a small machine process for the precise processing of a wide range of materials. The garnet abrasive employed is considerably harder than the majority of processed materials, but the hardest workpieces do pose a challenge for the process. Waterjet cannot match the processing speeds of laser cutting on thicker, hard substrates. In terms of similarities, both waterjet cutting and laser cutting produce high-quality cut parts, are suitable for working with many materials, and both processes have a small kerf (cut) width.

CNC Machining

CNC machining is considered one of the more traditional methods of extracting parts from flat material stock. It is similar to laser cutting in that both produce high-precision parts, are fast, reliable, and provide excellent repeatability. Compared to laser cutting, CNC requires more setup and more processing time. CNC also delivers lower throughput/capacity and requires greater manual intervention. However, results can be of similar quality, albeit at a generally higher cost. Rotating cutting tools apply considerable forces to the cut material and can result in more extensive local heating. The main advantages of CNC processing are the ability to accommodate complex 3D designs and to perform partial depth (rather than through) cuts.

Robotic laser cutting offers some useful benefits over more conventional forms of laser cutting automation. But, you might still be unsure if it’s the best approach for you.

Why would you choose to use a robot instead of a laser cutting machine?

What are the disadvantages of opting for a more conventional machine?

The new age of robotic laser cutting has already arrived. Here is the key information you need to decide if it’s the right choice for your business.

The Conventional Approach: Laser Cutting Machine

Automated laser cutting is nothing new. Most machine shops and many manufacturing facilities already have a flatbed laser cutting machine.

Want more information on Robotic 3D Laser Cutting Machine? Feel free to contact us.

Laser cutting is used in a wide variety of industries including automotive, jewelry manufacture, and silicon manufacturing.

Flatbed laser cutting machines are extremely useful. They are very versatile compared to more traditional forms of cutting, such as band saws and water jet cutting. They can be used for both cutting and surface etching.

Despite their versatility, conventional laser cutting machines are not always ideal.

For one thing, they are often expensive. Commercial laser cutting machines can range from $20,000 to $250,000 or even more. Even if this is a reasonable price for the return you will get, the problem is that the machines are only suitable for one particular task — cutting on a single plane.

You need to be cutting a large number of products each day to justify the expense of such a machine.

The Disadvantage of Using Laser Cutting Machines

There are other potential disadvantages of using conventional laser cutting machines.

Limitations of laser cutting machines include:

• Single purpose — As mentioned above, a laser cutting machine is essentially single purpose. It can only cut or etch on a single plane.
• They’re huge — A laser cutting machine can easily take up a whole section of a machine shop. This means that investing in a conventional machine also means giving up considerable amounts of floor space.
• They require supervision — Like many CNC machines, laser cutters aren’t completely autonomous. They require supervision from a skilled operator. This adds to the cost of using a machine as you also need to factor in the salary of those supervising workers.

Want to perform cutting tasks? You need multiple machines

The limitations of each individual laser cutting machine add an extra disadvantage that people often don’t realize.

They mean that companies often need to buy multiple laser cutting machines to achieve particular tasks. For example, you might use different machines to cut different shapes of parts.

This significantly adds to the budget and space required to use laser cutting machines. Like many manufacturers, you might start by assuming that you only need one machine only to realize later that you will need several.

Robot Laser Cutting: A More Flexible Approach

How can you overcome these disadvantages of conventional laser cutting?

How can you improve the flexibility of your cutting process while reducing the amount of floor space used by laser cutting machines?

Robot laser cutting is a relatively new manufacturing operation. Thanks to the continued advancement of robotic technology, it is now easier than ever to take advantage of this application.

You might think that lasers and robots are a strange pairing. However, lasers are an increasingly common end effector for robots. The agricultural industry even has robotic weedkillers that use lasers instead of pesticides.

How robot laser cutting works

Laser-cutting robots are pretty simple.

You add a laser end effector to the end of the robotic arm. Then, just like the cutting head in a conventional laser cutting machine, the robot positions the laser where it needs to be to carry out your cutting task.

How Does Robot Laser Cutting Improve the Situation?

Robot laser cutting overcomes many of the disadvantages of conventional laser cutting machines.

Here are a few benefits of using robot laser cutting:

• Robots are suitable for any cutting path — You are no longer restricted to cutting in only one plane, as with conventional machines. A robot can position the laser cutting head in almost any position and orientation within its workspace.

• Robots are extremely flexible — Which means that you only need to use one robot when you might have to use multiple conventional laser cutting machines.

• Large workspaces — Many industrial robots also have large workspaces which means you don’t sacrifice the large workspace you’d expect from a conventional machine.

• They take up less floor space — Even with their large workspaces, robots can end up using less of your floor space, especially when you consider that you only need one robot instead of multiple machines.

• They can run autonomously — When programmed correctly, a robot will be able to run completely autonomously. Moreover, they can take over tasks like depalletizing and material handling, which reduces human intervention to a minimum.

Programming Your Robotic Laser Cutting Machine

The key to getting the most from your laser cutting robot is to combine the hardware with a good programming system.

This ensures that you can quickly program complex paths into the robot even if you don’t have extensive programming experience.

The specifics of programming a laser-cutting robot will depend on the type of task you need to perform. If you use the robot to etch an image on the surface of the material, it will be similar to programming a drawing task. If you are using the robot for cutting, the task is slightly different.

You can find a tutorial on RoboDK laser cutting on our documentation page.

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