Laser welding is powerful – it offers high speed, high precision and excellent weld quality. Not that long ago, however, it was out of reach for most fabricators – from a cost and experience standpoint. In the past few years, though, costs have gone down while usability has gone up. Therefore, for fabricators exploring its potential for their operations, it will be critical to both select the correct laser welding equipment and ensure their operations are prepared to take full advantage of it.
This article, featuring insights and anecdotes from experienced laser experts from IPG Photonics Corp., takes interested fabricators through the primary types of laser welding equipment to help determine which is right for the job while offering advice to avoid common pitfalls. The article also lays out the value that comes from working with an experienced laser system integrator. Together, the information aims to create a clear path to take when adopting laser welding.
The welding way
Laser welding systems come in a variety of configurations, from handheld and cobotic systems to integrated subsystems, cartesian workstations and robotic welding cells.
Cartesian systems are frequently used for sophisticated and demanding laser welding applications. Often outfitted with advanced capabilities such as vision alignment and real-time laser weld depth measurement, cartesian systems achieve the highest accuracy and precision possible. These systems typically utilize the X, Y and Z axes, but additional rotary axes can be added as needed for increased capability.
“Many of IPG’s cartesian systems are sold into the medical world, where precision is non-negotiable, but they are also utilized in industries like automotive and aerospace,” explains Bill Kallgren, IPG’s systems marketing manager and a laser industry veteran. “This type of system is flexible and supports both hand-loaded and automated configurations as well as practically any kind of customization you can dream of.”
On the other end of the spectrum are IPG’s handheld laser welding systems. Since the company launched LightWELD, the world’s first air-cooled handheld laser welder, the technology has experienced steady adoption in operations of all sizes – from individual creators and small fab shops to massive manufacturing facilities. And there’s good reason for that – handheld solutions are easy to deploy onto a production floor and are great for high-mix product environments.
Dan Earley, LightWELD product manager at IPG, says that handheld laser technology requires straightforward safety considerations that are often misunderstood. “There’s a lot of bad information out there about how lasers work,” he says, “but almost any operation can integrate a handheld solution safely with some basic precautions.” He notes that ensuring operator and bystander safety means setting up a laser-controlled area, sourcing properly rated PPE and naming someone at the facility that will be responsible for laser safety.
For fabricators that are interested in handheld laser welding but need an effective way to augment human labor, LightWELD has also been integrated into a turnkey cobot laser welding system. The LightWELD cobot system features a pendant for simple part programming; teaching the system to weld a part is as easy as moving the robotic arm through the potential weld path. No matter the experience level, cobot welding systems like this one are ideal for low-volume, high-mix production and repeatable results.
For higher throughput needs, manufacturers often turn to integrated laser welding subsystems and robotic laser welding systems. Integrated subsystems, often used in larger production lines with specific requirements, combine a laser source with specialized beam delivery, motion and supporting technologies like real-time laser weld measurement. Full robotic systems, on the other hand, are better-suited for operations looking for a turnkey solution. IPG’s LaserCell robotic laser welding systems are still flexible and highly customizable with the flexibility to be configured in a variety of ways, including with one or several robotic arms and with a variety of part loading and automation options.
“While robotic systems can feature six or more axes of motion, they aren’t quite as accurate or precise as cartesian systems,” Kallgren explains. “But, only a few industries require the level of precision delivered by a cartesian system – traditional robotic laser systems are typically more than accurate enough for most applications.”
Similarly, the differences between a traditional robotic and cobot laser welding system include the speed, accuracy and power levels that are needed. While the LightWELD cobot system can often increase productivity compared to the handheld option, limitations to cobots should be considered. Higher power levels come with heavier welding heads that some cobots can’t handle. Likewise, some end-of-arm tooling is too heavy. Some fabricators may require a longer reach not possible with a cobot. Alternatively, compared to traditional robots, cobots are often much easier to program.
Factors to consider
Understanding the characteristics of the various laser welding systems can help narrow down the options, but it’s just the first step in arriving at a decision. To achieve true success, it’s key to define the technical and commercial objectives before making the investment.
Some of the main factors to consider on a part or product level include product functional requirements, the materials to be welded and their sensitivity to heat input, weld joint configurations and how well those parts fit up. Understanding the physical limitations of a part, however, is just one aspect of the overall decision-making process. Evaluating the company culture may also be necessary.
“Handheld systems are easy to deploy onto a production floor,” Kellgren says, “but deploying a more complex system to a shop floor that’s lacking discipline and adequate resources, such as engineering support, can be a recipe for disaster.”
As is true with any new piece of equipment, it’s important to ensure that the available workforce possesses the skill levels for success. For more entry-level laser welding systems, like LightWELD and the LightWELD cobot, general labor and maintenance capabilities will suffice, but for particularly complex systems, highly skilled programmers, operators and maintenance technicians may be necessary.
A sometimes-overlooked factor to consider is employee buy-in. When employees understand why a new technology is being adopted and how it will improve their workday, the potential for success grows. And that’s definitely the case when an equipment champion is designated. The goal for this equipment champion is to become the subject matter expert and overall system cheerleader. Keep in mind, however, that redundancy may be needed in the event of employee turnover.
In addition to company culture considerations, upstream capabilities must also be assessed. To do so, Kallgren suggests asking the following questions: Are upstream production tolerances adequate to support laser welding downstream? Are there any problematic processes upstream that may need to be resolved before a laser welding solution can be adopted successfully? Does the part need to be redesigned to resolve manufacturing issues, regardless of welding technology?
Furthermore, it’s key to evaluate the laser process parameters and process window. This entails testing an internal part during a product demo or, when a system integrator is involved, having them test it.
Regardless of the scenario, test materials should be as close to the production samples as possible. In doing so, laser process parameters can be identified, including but not limited to the required laser power and spot size, pulse parameters, wobble characteristics, beam profile and sensitivity to focus variations. Keep in mind that this portion of the process can be iterative and it takes time to identify the right parameters and system configurations – especially for fabricators that choose not to work with a system integrator.
In terms of budget considerations, be sure to factor in the potential for upgrades to upstream equipment as well as the facility and staffing requirements that may be needed to deploy the technology.
Working with integrators
Working with a system integrator ensures success while avoiding the risks often associated with “going it alone.” Their experience can help fabricators sidestep unnecessary features; choose appropriate tooling, automation and system setups; and establish new maintenance practices and routines. According to Earley, while the bulk of handheld laser welding users won’t require a system integrator, they can be helpful when there are questions about what’s needed to successfully deploy a new system. “LightWELD is built with a variety of features and presets that make it easy to get up and running quickly – but it’s a good idea for shops new to handheld lasers to reach out to the manufacturer with any safety questions they might have.”
In the case of workstation applications, as with IPG’s cartesian or robotic laser welding systems, integrators with a high level of laser experience can be integral. Taking a lot of the headaches and uncertainty out of the picture, they ensure that laser process recipes are robust, which minimizes delays in getting production equipment qualified and allows customers to make money faster.
“Qualified system integrators have experience with the options available to best determine what features may be more important,” Kallgren says. “They can tell you what you don’t need to keep costs and complexity down. Finally, they should tell you when your expectations are unrealistic.”
For fabricators that choose one of IPG’s many laser welding systems, the company is more than equipped to play the role of system integrator. Working concurrently with the system build, IPG’s experienced engineers are intimately familiar with fiber laser welding technologies and can offer deeply informed recommendations about the process.
At IPG and other top-tier system integrators, advanced software modeling tools can be leveraged to simulate production outcomes. These simulations can put tooling models and processing parameters to the test – and can even simulate production runs of thousands of parts. It’s an incredibly quick method for identifying areas of improvements, such as material loading and unloading, fixturing and beyond.
Even after the laser welding system has been defined, designed and installed, integrators can be incredibly helpful when post-sales support is needed – as long as the integrator was properly vetted, of course.
“Well-staffed organizations are able to quickly respond when problems arise,” Kallgren says, “but integrators that aren’t staffed appropriately may point the end user back to the subsupplier or be delayed in their response. This results in lost production opportunities.”
Sticking the landing
Regardless of the chosen laser welding system, the overriding goal is to experience a smooth rollout and then long-term stability. Sometimes, achieving that is as simple as being realistic – realistic about expectations, capabilities and needs. Honesty goes a long way, too. When making an honest assessment of an organization and its staffing capabilities, pitfalls can be avoided.
With years of experience helping fabricators assess their needs, Kallgren has encountered almost every type of fabricator out there. Over time, he’s recognized that the needs of one fabricator will be completely different to the needs of another. A custom fabricator’s needs are wildly different than those of a medical manufacturer, as just one example.
Regardless, Kallgren stresses one thing perhaps more than all the rest: Don’t confuse the “price” of a laser welding system with its cost. A low-cost system that isn’t engineered or specified properly may cost more in the long run.
- This is true for a handheld system if it requires maintenance and service isn’t readily available.
- This is true if substandard tooling is used. This can result in more variation in part-to-part output due to variation in part loading.
- This is true for operations that don’t price equipment to maintain a stable business operation, including investments in applications capabilities, sufficient R&D and on-going product support.
And, as previously mentioned, be honest with the equipment provider and system integrator. Without transparency, things can go awry. Kallgren describes a situation where a top semi-conductor manufacturer was developing an undisclosed new product.
“They were so secretive that they misled us on the actual material to be processed,” he explains. “Unbeknownst to us, they provided surrogate material for us to experiment with. A few weeks prior to factory acceptance, they sent the actual materials, which turned out to be completely wrong for the system we developed.
“The machine was used off and on for other projects and with less than 100 hours of operation, it was put in a crate and sent to storage,” he laments. “Ultimately, it was sold to a startup at a fraction of the cost.”
