Welding shops with high volume and low variability have a clear automation option. So do shops with low volume and high variability. But what about all the shops stuck in between?
‘Automate or evaporate” is becoming an often-voiced mantra in welding shops.
The top 30% of the market, which includes a lot of automotive and heavy industry-related companies, heeded the call some time ago and are already benefitting from the efficiencies of automation. It’s the remaining 70%, who may have bought into the need to automate, but remain uncertain about the best way to go about it.
For those whose operations require welding a high volume of the same part, the need to move to automation seems obvious, despite the initial cost and training required. For those with low volume and high part variability plus the need to bring the robot to the part, a cobot, with its lower cost, safety requirements, and training needs, would be the better option.
But how about the many shops in between those two extremes? Those shops who need the production speed of a more heavy duty industrial robotic welding experience but don’t have staff with CAD experience. Or those shops who have a high-mix, low-volume production but don’t want to commit to the intensive training necessary to bring their welders up to speed with programming robots—what’s the best option for them?
“Robotics is pretty complex, especially if you are doing path intensive things like arc welding. In the industry everyone has their own interface, everyone has their own program, everyone has their own offline programming system,” explains Tom Fuhlbrigge founder and CEO, of Scalable Robotics. “If you know how to program an ABB you literally have no idea how to program a FANUC, they’re just opposite ends of the world in terms of how to program a robot. It tends to make things difficult.”
Training a welder to be a programmer can take at least a couple of weeks of training and multiple weeks afterwards getting up to speed in applying what the welder learned in class to the plant-floor realities of robot programming. Once that expertise is gained, there is always the risk it can walk out the door. Fuhlbrigge shared the story of one customer who had three welders trained to program, a process which took weeks, and within six months all had left the company. The customer spent $45,000 on training and time for welders turned programmers to get up to speed on what they had learned and yet he was back to square one.
Fuhlbrigge, who was a guest speaker at the ABB Robotics Canada’s inaugural Welding Automation Week, believes he has the answer.
“There is a better way. You don’t need to make your welder into a full-fledged robot programmer. We can make him behave like one, but he doesn’t really need to know all the details of expert robot programming,” Fuhlbrigge assured. “The vision that we had is to enable a non-expert to behave as an expert and the way you do that with arc welding is to show a robot what needs to be done just as you would show a person.”
His company’s ScalableArc works with any size robot and external axes. The platform uses a 3D camera attached to the robot end-of-arm tooling. The welder starts the process by pressing the “scan” button, instructing the robot to generate a representative model of the part. The robot takes 300-400 different images to create its 3D model. No CAD of the part or even knowledge of how to use CAD is required, Fuhlbrigge points out.
Next the welder teaches the robot the position of the welds to be made by clicking a handheld teaching stylus at the desired approach, path, and departure points of the weld. The “validate” function key ensures the robot can reach all the points shown. The welder can then make any necessary changes to the automatically generated program, or if the path and torch angles are satisfactory, the program is sent to the robot controller for auto tuning.
Because the system knows the geometry of the part and the location of the weld, it can automatically create search paths that use the robot’s built-in weld wire touch sense to accurately locate the part surfaces. It then places the torch tip in the right position for that weld type and gives the welder the opportunity to make changes, if required, by tapping buttons with simple labels like “left” and “right” to adjust a point in the weld seam.
Fuhlbrigge says his Scalable Robotics system has been shown to lower the programming time for new parts by about 12-fold compared to the traditional pendant-based teach-thru style used with most robots currently.
“We have a lot of customers come to us and say we are not using our robot as much as we should because our production run is too short, and the programming time is too long. I tell them we can bring that programming time down so that it makes sense to use the robot since once programmed the robot is so much faster at production,” Fuhlbrigge says. “We had one customer doing automotive aftermarket parts for exhaust systems and their teach pendant programming would take them about eight hours to perform. So I asked them how they schedule in the programming time (with the Scalable Robotics platform) and they told me they don’t bother because it’s only taking them 22 minutes to program a part now with the robot.”
Fuhlbrigge says his target market is small to medium-sized shops and he understands their challenge to meet the market price for the parts they’re producing.
“If you can’t bring your costs down and bring your productivity up, you can’t produce where the market price is. So in welding there is the productivity driver and also the lack of welders acting as a driver,” he says. “The barrier is in trying to find an
ROI and finding something where you’re not investing so much into programming, training and people.”
One thing that is certain is the improved efficiencies that robots can deliver once a shop takes the leap of faith.
A traditional industrial robotic cell with two stations can have a 75% or better arc-on time because even a good manual welder, as research shows, can only achieve up to 25% arc-on time. They spend the rest of their time on part adjustment and other tasks as well as resting because welding can be so physically demanding. With a robot handling the welding on one station, the operator can unload newly welded parts and load fresh parts for the robot to weld on the next station with no delay.
“Robots work great, once you get them up and running,” Fuhlbrigge says, and he’s hoping to play a significant role in helping shops make that happen. SMT