A Swedish shop MIG welds heavy buckets for excavators. The fact that the robot is easy to move to the workpiece, instead of having to move the workpiece to the robot, is a big advantage.
Collaborative robot-based welding systems—or cobots—have come a long way in just a few years. Thanks to the emergence of new welding capabilities and increasingly intuitive programming methods, cobots with greater reach have hit the market. The first wave of cobot-based welding robots typically were used for simple welding jobs and mounted on a fixed table, but the latest advancements can handle even more complex weldments with external axis positioners, linear rails, and coordinated motion.
Welding cobots expand manual welder productivity by raising arc time per shift, expediting changeovers, and accelerating the setup of new parts. In addition, these welder-friendly, portable robots drive up production quality and consistency by improving process repeatability and reducing rework queues.
And crucially, given the turnover in welding labor, cobots can increase welder engagement and retention by taking care of the unfulfilling, unergonomic, repetitive, and hazardous welding tasks. This reduces welder exposure to hazards and the physical toll of welding, enabling the worker to focus on more creative and value-adding tasks.
And if the first wave of cobots were best suited for high-mix, low-volume tasks, today’s leading cobots can easily handle traditional high-volume production and have even found a sweet spot in medium-mix, high-volume environments.
Today’s leading welding cobots can take on jobs that were once exclusively associated with traditional welding automation and at a fraction of the cost of deploying and managing traditional welding robots. As a result, the line separating cobots from traditional industrial robots has blurred even more.
Portability: New Territory and New Applications
Cobots remain truly unique in one area of automated welding: portability. This is creating opportunities to introduce robot welding where traditional welding robots have not been able to go.
A cobot’s portability enables users to bring the robot to the weld, rather than bringing the weld to the robot. For instance, cobots can be picked up and moved easily or even mounted on temporary tracks to make their way around the workspace to the next weld, enabling them to perform practically unlimited large welds on ships and other heavy equipment, on both curved and flat surfaces. Cobots can go where no welding robot has gone before.
Lightweight Automation
The key to cobot portability lies in its light weight and small form factor. Cobots are smooth, with rounded edges to enhance safety when deployed close to humans. But that’s just part of the picture.
Their lightweight nature, combined with the ability to work in spaces similar to human workers—where traditional robots struggle—means they can easily be picked up, placed on a dolly, and moved around or repositioned.
With their approachable usability and ease of programming, cobots bring a more human-friendly (and much less intimidating) experience than traditional welding automation.
Traditional robots aren’t ideal in low-volume, high-mix manufacturing environments that deal with large, difficult-to-move workpieces. Cobots allow shops to bring the robot to the work—rather than the other way around.
In this context, think of cobots first and foremost as easy-to-use tools designed to supplement what a person can weld manually. They can be brought with the welder to the work, like a carpenter’s hammer or a plumber’s wrench.
In practical terms, cobot portability creates opportunities to deploy automation quickly and conveniently on large weldments and heavy equipment. These are jobs that up until now required manual welds, often in dangerous locations and unergonomic positions. Bringing the welding cobot to the work is like giving a welding robot a VIP all-access pass to welding jobs, regardless of how big or awkward the welding project requirements are.
It also makes welding automation adoption realistic for new fabricators across new sectors including energy production equipment, municipal infrastructure, construction, yellow goods, and agricultural equipment.
Levels of Portability
There are different ways to bring a welding cobot to the weld. Let’s look at some examples, starting with entry-level portability and ending with the ultimate in flexible, portable automation.
In its simplest form, portability might involve putting a cobot on a dolly and bringing it to the next welding cell. While rotary positioners can help, this doesn’t solve the challenge of dealing with very large assemblies. This was one of the challenges faced by an Ontario, Canada-based producer of heavy earth-moving equipment for harsh mining environments. To enable MIG welding on massive 15-ton workpieces, the company developed a custom skid that can be moved with a forklift to wherever the cobot is needed. The cobot then is mounted on a lift to create a seventh axis to reach the entire weld on the side of a truck body. With this skid, a welder and robotic welder work side by side, leapfrogging across the fillet-welded ribs on the side of the truck body, doubling the output.
Mobile cart-based welding cobot solutions have entered the market in recent years to exploit portability. In one example, a New Mexico-based agricultural equipment manufacturer has been using a mobile cart-based cobot to automate repetitive welds on larger parts in the fab shop. The manufacturer discovered that for large parts, it is much easier to bring the cobot to the weld than it is to move the part around. The result is a level of portability that just isn’t possible with traditional robot welding systems.
Another approach—one that creates even more new robot welding opportunities—is to mount a welding cobot on movable magnetic rails. The cobot can “crawl” along gigantic flat or curved workpieces performing welds, freeing workers from a lot of stress in the process. Don’t be deceived by a cobot’s small form factor and portability—these systems can even handle heavy-duty multipass jobs on large weldments.
Traditionally, in high-budget production, these applications were solved with the use of large rotary positioners, long rails, or expansive gantries with traditional robots. But many fabricators have neither the skill set nor the available capital to afford these solutions. These fabricators have been left out of automation until now.
In an arguably extreme example of portability, cobots can even be magnetically mounted to any metal surface, enabling welding automation in the type of cramped and awkward locations that once required manual welding by default.
This capability is being leveraged by some in the shipbuilding and construction sectors. Shipbuilding requires extensive inside-block welding on all the ships’ internal rooms and cubby holes—a job that until now has had to be performed manually. And in construction, the ability to bring the simple-to-program cobot to the work has saved a Swedish bucket repair company 30% on its working time, giving it the opportunity to take on more complex welding assignments.
Mobile cobot welding machines provide flexibility and portability in high-mix heavy fab shops.
Know Your Cobots
There’s little point to having a welding cobot if it’s a nightmare to program. When selecting a welding cobot, fabricators should look for systems that score high on usability; a skilled welder should be able to learn how to program simple welding in less than a day. Look for intuitive interfaces and cobot companies that provide online training and certification to bring users up to speed on how to operate the robot.
And to future-proof the investment, fabricators should choose a proven cobot from a reputable manufacturer. These companies have created welding-oriented tools and programming interfaces so fabricators don’t have to waste time in the design and deployment phase.
Ultimately, no matter which level of cobot portability a metal fabricator embraces, bringing the cobot to the work is about making people more productive, ensuring better quality of the end product, and improving the well-being of welders.
New, innovative ways to deploy welding cobots include a cobot placed on a carriage that runs on a flexible rail system fixed to the substrate. It specializes in butt-weld connections and multipass welding, regardless of the shape or orientation.
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