How the welding cobot is changing the metal fabrication shop

0

An operator monitors a benchtop welding operation in action. Red-D-Arc Welderentals

Collaborative robots have come a long way over the past decade, especially in metal fabrication. They started as a curiosity. Some stores bought a cobot or two just to see what they could do with them. Yes, they could perform light pick-and-place tasks, but this has limited applicability in sheet and plate fabrication. What about servicing a press brake, or maybe a hardware store or a stamping press? Maybe an ironworker?

These early applications mainly involved pick-and-place actions: take this part and place it in the assembly; place this flat blank against a magnetic backgauge on a press brake. Over time, applications have become more sophisticated. The cobots did not just place parts, but rather manipulate them throughout the cycle. On a press, for example, cobots not only picked and placed simple single-bend parts, but now transported parts through more complex bend sequences.

At the same time, welding cobots began to hit the market and industry thinking about cobots began to change. They were no longer a novelty for simple applications. The cobots now approached the field of semi-skilled labor. And for fabricators, a cobot wielding a lightweight welding torch and associated reels and gas lines made more sense than using a limited payload cobot to lift and hold heavy or bulky sheet metal or plate parts.

Cobots have made stores think about automation differently. Automation is not an all-or-nothing concept, but rather an array of innovations that change the way workers interact with machines and technology. And more than many manufacturing technologies, cobots have driven workshops to focus on making the most of this human-machine interaction.

A spectrum of automation

Failed attempts to use automation are certainly not unusual, with a telltale sign being a dusty welding robot or two sitting in the corner. Perhaps the fabrication shop had trouble reassigning them after a high volume welding job was completed. Programming was taking too long. A welder could simply fix and weld the job rather than worry about programming complications.

Certainly, more precise upstream processes have made downstream welding automation more practical in many situations. But that still misses another reality of modern manufacturing: 3D CAD models aren’t as ubiquitous as many think. This fact makes adopting a host of automation options, including offline programming and simulation, a bit more complicated.

“We take the automation-as-a-tool approach,” said Josh Pawley, vice president of business development and founding partner of Loveland, Colo.-based Vectis Automation. “There is a real risk in over-automating. We see so much value in the person-plus-machine approach. We keep the operator up to date and always ask: “Does this application really need to be fully automated?”

Most welding cobot applications involve benchtop welding. Programmers fix a part, use a simplified interface to teach the robot, then let the cobot produce. This programmer could leave assembly and removal of parts to a material handler or helper and travel elsewhere to weld parts that are not suitable for the cobot, including large parts.

But as Pawley noted, this is only one approach. He described some manufacturers who have welders setting up a cobot and then working on another manual welding application alongside. Alternatively, a welder/programmer can spend a shift managing a “team” of cobot welding cells.

Some manufacturers have even pushed cobot applications beyond tabletop welding. A structural fabrication shop, Pawley said, attaches its welding cobot to the job, almost like a magnetic drill, designing its setup to make the entire welding cell easily transportable.

welding cobot in metal fabrication workshop

Vectis Automation

These automation strategies boil down to finding where the cobot fits best, helping a shop make the most of the skilled workers it has. Pawley described a manufacturer of fire trucks and firefighting equipment that now uses cobots to create thousands of spot welds for a fan shroud component. “The company makes 100 a week, which equates to about 14,000 trigger pulls for one welder. It’s a miserable job, but it’s a holy grail app for a cobot. It’s boring and repetitive.

The adoption of cobots freed up company welders to work on large fire trucks. “And those fire trucks are a horrible cobot application,” he said, adding that these are unique products that require a myriad of out-of-position welds.

Joe Holloway is vice president of Red-D-Arc Welderentals, a subsidiary of Airgas Co., based in Atlanta, Georgia, which developed the BotX welding cobot platform in conjunction with Hirebotics. Holloway described an application where a cobot had to reach inside a deep box to weld corner joints, a feat not possible with a standard tabletop setup. To remedy this, the company mounted the robot overhead so the arm could reach deep into the box and weld the joint.

Holloway added that this setup, while atypical, didn’t require a massive investment, nor did it take a long time to fit in and set up. This fact makes cobots less of a single-purpose machine and more of a widely applicable tool.

Their physical nature allows this (they are small and can therefore be moved easily), as does the programming platform. Welding cobots are taught with a combination of kinetic teaching (moving the cobot by hand along the desired welding path) as well as commands, via dedicated tablets or even specialized apps on smartphones, designed to make the intuitive programming, especially for those familiar with welding. Programmers define start and end points, then choose from various “welding recipes” that specify a range of details, including the distance between the torch tip and the work, techniques such as beads or weaves, weld geometries including size, and stitch options. welding. Companies use these recipes as a good starting point. “As you can imagine,” Holloway said, “there are so many variables with each specific application, it’s almost never the case that fine turning isn’t necessary.”

“The main thing is that people use [welding cobots] as a tool, and they integrate them in so many different ways,” Pawley said. Cobots can automate the fitting, joint tacking, and staging of various parts for manual welding. Others use the cobot for production welding, while fitters do the tacking manually. Sometimes the cobots partially weld the seams and then go straight to a manual welder who completes the remaining seams that the cobot couldn’t reach. In short, there is not just one way to integrate a cobot.

“We view cobots as force multipliers,” Holloway said. “You take advantage of your skilled welders, who may see a cobot as some kind of smart tool. The skilled welder can teach the robot, while the less skilled can run programs and produce. »

Automation as a service

Technological change in metal fabrication has only accelerated. It’s a safe bet that tomorrow’s automation will tackle problems in new ways. Whether they are better way depends on the manufacturing challenges in a particular workshop. Yet manufacturers face the increased risk of automation becoming obsolete, hence the growing popularity of a somewhat new concept in metal fabrication: automation as a service.

Both Vectis Automation and the BotX platform offer rental options. Sources from both companies said most stores end up owning their cobot cells, but the rental option at least entices companies to make the leap into automation.

“It’s about lowering the barrier to automation and meeting people where they are,” Pawley said. “We call it ‘automation without boat anchors.’ If it doesn’t fit the application, we’ll take it back and find it a new home.

The welding cobot is working on a metal part

A cobot welder performs a multi-pass weld on a profiled seam. Vectis Automation

But as Holloway explained, the flexibility of cobots makes them particularly suited to the business model. “If you have a traditional robotic welding cell, you have all the fences and roll cages, and it takes up a significant amount of floor space. On the other hand, manufacturers are just rolling their cobots inside existing welding booths, where welders will weld alongside them. They don’t have to change their process just to accommodate the cobot. It’s the opposite. They can adapt the cobot to the process.

Cobots have their own set of security protocols; a cobot may be limited in strength, but it can still hurt someone, especially if the cobot is wielding something sharp or hot. Even so, cobots in many applications do not require a security fence. This means they can walk in and out of a shop’s manufacturing operations without too much disruption.

A manufacturer served by automation

Slipping in and out of existing production, increasing the value of skilled personnel, could become the hallmark of the future fabrication shop. Imagine a precision sheet metal operation in which much of its manufacturing technology is not owned by the fabricator. Instead, the manufacturer pays a monthly fee. In a sense, the shop pays for technology as it pays for labor, incrementally and over time.

It does this sometimes when adopting new technology. Will a cobot suit our operation? Let’s praise it and find out. The shop could possibly own the equipment if it is profitable and commercially sensible to do so. Or, if the technology doesn’t fit or the product line changes, manufacturers can return the leased cobot to the supplier and move on.

At the same time, greater automation becomes easier to integrate and slide in and out of production as needed. Cobots increase the welding capacity of a workshop. Their small form factor means they can be moved as needed to different work tables or even large workpieces, becoming the magnetic drill of the fabrication shop, without any 3D CAD model of the part being required. necessary.

Production strategies no longer need to be designed to make the most of automation; now automation can be adapted to help overcome the challenge. In other words, automation serves the operation, not the other way around.

Share.

Comments are closed.