Cobots, or collaborative robots, are robots designed to work with and around humans. Like any robot, cobots enable repetitive tasks to be completed more efficiently and more precisely.
If you are considering a cobot to increase welding productivity and safety in your operation, read on to learn everything you need to know to get started with a laser welding cobot solution.
What is a Welding Cobot?
While cobots are utilized for a variety of tasks, they have experienced a surge of adoption in manufacturing and fabrication applications like welding. Cobots for welding combine a multi-axis robotic arm with a welding torch and power source and are capable of performing many welding operations. Cobot arms can be mounted in a variety of ways but welding cobots are typically mounted to a table or cart with a surface for fixturing workpieces.
Welding cobots can utilize the same handheld welding methods as a human welder, including laser welding, MIG and TIG, ultrasonic, plasma, and spot welding. Choosing the ideal welding method is critical when selecting a cobot welding system as many of the advantages and disadvantages of each method persist regardless of the level of welding automation.
What Are the Advantages of Laser Welding?
Laser welding is the process of transferring a laser beam’s energy in the form of heat to fuse or join parts. Laser welding, whether handheld, fully automated, or integrated with a cobot, offers a number of significant advantages.
Precision & Repeatability
Laser welding is remarkably precise and offers consistent results weld after weld. As a non-contact process, laser welding experiences virtually no degradation in weld quality over time. The precision of laser welding pairs excellently with cobots because both the process and motion are highly controlled and repeatable.
Heat & Distortion
Laser welding directs heat very precisely and generates significantly smaller heat affected zones than alternative welding methods. Since laser welding transmits minimal heat to the surrounding material and greatly reduces workpiece distortion, it is an excellent choice for sensitive features and thinner materials.
Flexibility
Laser welding can be performed with and without shielding gas and in a range of materials and thicknesses. Steels, stainless steels, aluminum, copper, titanium, nickel, brass, and dissimilar materials are all excellent candidates for laser welding.
Welding Speed
For many applications, laser welding is significantly faster than alternative welding methods. This advantage is most pronounced in fully automated systems, but the higher welding speeds carry over to handheld and cobot applications. Laser welding has experienced widespread adoption largely because it is up to 4X faster than alternative methods like TIG.
Weld Quality
Laser welding creates exceptionally high-quality joints with excellent visual finish and mechanical properties. Lasers can create both narrow and wide weld seams depending on how laser parameters are set and can be used with wire feeders to create larger weld beads and fill wider gaps. Laser welded seams often require no or minimal finishing beyond a quick pass with a brush, further reducing tedious manual labor and increasing productivity
Weld Cleaning
Lasers are used for a wide variety of tasks in fabrication and materials processing beyond welding. Laser cleaning is one such application that has surged in popularity due to its speed and flexibility. Some laser welding systems offer pre-weld cleaning to minimize porosity in the weld joint due to contaminants while post-weld cleaning functionality reduces or eliminates the need for slower weld cleaning methods like blasting, pickling paste, and grinding. These laser cleaning functions are powered by the same laser as the welding functions and are accessed easily by changing the torch nozzle.
What Applications Are a Good Fit for Welding Cobots?
Choosing between a handheld laser welder, fully automated laser welding, or something in between is a big decision, particularly for smaller fabricators and shops. While there are a number of factors to consider, one of the most critical is what kind of applications, projects, and parts you expect to encounter.
Ultimately, laser welding cobots are a form of automation — while they bridge the gap between human welders and traditional robotic systems, automation is most effective when handling repeat tasks.
The two primary benefits a cobot offers are productivity and consistency. Once a welding cobot is taught how to make a weld, it can do so virtually perfectly (and quickly) over and over again. This is true whether the cobot has been taught 10 welding tasks or 100. Welding cobots truly shine when handling repetitive welds in High-Mix Low-Volume manufacturing environments.
Repetitive welds can come in many forms. On one end, a high volume of small parts that require a single weld are a good fit for a welding cobot as multiple can be fixtured to a weld surface and addressed as part of a single program. On the other end, larger parts that require multiple welds, such as vehicle seats, are also often excellent candidates for welding cobots. The flexibility and ease of programming means that welding cobots can handle one project one day and seamlessly pivot to a different project the next day.
The same is true, of course, of human welders. However, no amount of welding skill or experience can completely eliminate mistakes, imperfections, and inconsistencies. If a weld must be made to an exacting spec, and imprecision means extra finishing steps, rework, or scrap, a welding cobot can be the answer.
Welding Automation & the Welding Labor Shortage
It’s no secret that the welding profession has seen some challenges in recent years with skilled welders becoming significantly harder to find, hire, and retain. The American Welding Society has projected there will be more than 300,000 open welding jobs by 2028 based on current openings, industry growth, and anticipated attrition due to retiring welders. Fabricators wishing to remain competitive must take steps to maintain their productivity.
Despite being a form of welding automation, it is important to understand that welding cobots are not intended as a replacement for skilled human welders. The opposite is true, in fact — by definition, collaborative robots rely on humans to teach and work alongside them. Even if that were not the case, welding cobots are not a perfect fit for every application, such as when parts have inconsistent fit up or require particular attention or care.
However, welding cobots offer a surprisingly affordable and easy to integrate way to increase welding throughput and productivity. The speed and consistency achievable with a cobot empower skilled welders to get more done while reducing fatigue and letting them focus on higher skill tasks rather than repetitive jobs. By increasing welder productivity and decreasing the amount of time spent on mundane work, welding cobots help fabricators stay competitive and make welding a more attractive profession.
How Do You Program a Welding Cobot?
The primary way that human welders interact with a welding cobot is by programming it to perform welding operations. Programming is a key differentiator between cobots and traditional industrial robots. Traditional robots typically require workers with robotic programming experience — even then the process is usually complex and time consuming. By comparison, welding cobots can be programmed by operators with no programming experience in as little as a few minutes.
Although cobots can be programmed using traditional g-code, this is usually not necessary. The most common method of programming a welding cobot is teach-by touch. Teach-by-touch refers to manually guiding the robotic arm through the steps of the welding job before saving the program. Creating the weld move profile in this way involves setting waypoints like weld start point and weld stop point. Welding cobots can be manually programmed by physically moving the arm by hand or by using a controller pendant to jog the arm.
Programming a welding cobot does involve more than just taking it through the motions, however. Most welding cobots include software accessed on a controller that allows operators to define weld parameters. In the case of the LightWELD® Cobot System, parameters like laser power, seam width, type of weld, and material are defined and exact welding steps are specified using a visual programming language.
Once a job has been taught operators typically run the cobot through the program with laser power off to confirm the cobot is behaving as intended before running the actual job. Laser welding cobots can store many different programs and parameter presets that can be recalled as needed once the operator is happy with the results.
Are Laser Welding Cobots Safe?
Safety is a primary concern for both welding cobot and laser welding solutions. Ensuring the safety of both operators and bystanders is easier than you might expect but still requires PPE and integration considerations.
Let’s start with cobots themselves. As robots designed to work in close proximity to human workers, cobots are usually equipped with a variety of safety features. Unlike traditional robots, which often require a cage to ensure they do not come into contact with obstructions, cobots are power and force limited, meaning that they do not move quickly enough to cause injury. In the event of collision with an obstruction, a welding cobot will immediately stop moving and shut off welding power. Cobots are also typically designed with rounded geometry and no pinch points.
Laser welding requires safety measures like any other type of welding. Welder PPE is necessary and should include heat-resistant gloves and clothing as well as eye protection. When laser welding is in-progress, laser safety goggles with an Optical Density (OD) rating greater than six at 1070 nm are the minimum requirement for anyone with a line of sight to the welding torch. For welders that are closer to the weld, a laser safety welding helmet is also required. Fumes must also be considered, and adequate fume extraction may require a dedicated fume extractor and respiratory protective equipment if the welding area does not have adequate ventilation.
The location where the laser welding cobot is installed must also be considered. Some laser welding cobots include interlocked enclosures that can be shut when the laser is on — this option allows the system to be installed virtually anywhere. Laser welding cobots without integrated enclosures must be installed in a closed environment with laser safe walls, interlocked doors, and safety signs. When integrating any laser solution, a designated employee should serve as the Laser Safety Officer (LSO) who ensures that laser safety best practices are upheld.
How Much Do Laser Welding Cobots Cost?
Cost is one of the most important, and attractive, aspects of a laser welding cobot system. Traditional robotic solutions are typically very expensive and require both a lot of floor space and complex integration efforts. Welding cobots are compact, easy to setup and integrate, and usually much less expensive than their traditional counterparts. Although laser welding solutions are seen by many as expensive, laser welding cobots are roughly equivalent in cost to alternative welding cobot systems.
Getting Started with a Laser Welding Cobot Solution
Implementing a laser welding cobot solution can seem intimidating, particularly for those with no automation or laser welding experience. Fortunately, the laser welding experts at IPG are ready to help. Getting started is easy — send us a sample, visit one of our global application labs, or just tell us about your application.
