Arc Welding Cells-in-a-box Answer Today's Customer Needs
by Winn Hardin
, Contributing Editor
Robotic Industries Association Posted 08/16/2002
Today's difficult economic environment and emerging standard interfaces are changing the shape of robotic arc welding systems. End users once concerned with the cost of the entire project - including purchase, integration and operational costs - are now taking more narrow views that tend to ignore many of the offsetting benefits that come part and parcel with flexible automation in general, and some robotics applications in particular. One result has been for robot manufacturers to emphasize and refine the way a system is sold so that users can choose from pre-packaged solutions.
According to industry experts, this shift in buying pressure has prompted arc welding robotic cell manufacturers to improve standard interfaces and increase their partnerships with other suppliers to create 'cells in a box.' At the same time, manufacturers of robot and tooling, and the system integrators that bring them together, are changing their business structures to provide more service for companies that have lost much of their robotic expertise through downsizing and budget cuts. While it remains to be seen if these operational and structural changes at the robot supplier level will last as the economy begins to expand and companies rehire engineering staff, the lessons learned during thin economic times will likely leave the robotic arc welding industry on firmer ground than ever before.
Is smaller better?
Hard times call for hard measures, and the sluggish U.S. economy has not spared the robotics industry. 'The jobs that are coming in are smaller in size. Rather than doing large capital robotic projects in the $3 million dollar area, companies are into less expensive systems in the $300,000 area - scaled down versions without all the bells and whistles,' said Dean McClenathen, president of Custom Machines Inc. (Adrian, MI), supplier of robotic arc welding cells to the automotive and furniture industries. 'The good news is that we're seeing more requests for quotes lately.'
Dan Davis, sales engineer for servo and pneumatic control vendor Festo (Hauppauge, NY), related a recent contract win that depended on a scaled down solution. Davis replaced a human operator at a robotic welding station with a two-axis servo-based pick and place robot. The cell welds carbide studs on grinding drums used to refinish roads. According to Davis, using a robot feeder for the carbide tips was initially cost prohibitive to the client, and a full five-axis robot would have been too much to win the deal today -- although a few years ago the client would have gone with the more functional robot upgrade to accommodate future product line growth. 'It was the right tool for the job in terms of cost and utilization,' Davis said. 'The robot has doubled the output within the same shift and can run around the clock.'
Most of the companies interviewed for this story told similar tales, reporting upticks in the number of smaller welding programs coming up for bid. 'In the last few months, we've seen some new programs released. We're down stream a bit from those programs, but we're tracking some things that are very optimistic and should bear fruit between the third quarter of this year and the first quarter of next year,' predicted David Dibiase, director of sales for integrator and system supplier Robotic Production Technology Inc. (Auburn Hills, MI).
2 for 1
In the meantime, customers are asking suppliers and integrators to supply more services and take more ownership of the welding cells they provide. 'The biggest trend we've seen is single source solutions for robot welding systems. That means a safeguarded, highly mobile arc welding cell that comes with robot, power supply, torch, cleaner, reamer, everything except the part fixture,' said Robin Schmidt, engineering specialist with Nachi Robotics Systems Inc. (Novi, MI).
Often referred to as a 'cell in a box' or 'pre-engineered cell,' these systems are helping robot suppliers grab a bigger part of the welding market. 'We're putting more value added items here on this side of the ocean. More labor and more components with a wider profit margin than we had with just a 'robot in the box,' Schmidt explained. While Schmidt concedes that expanding your business model in these economic times can be risk, 'We're trying to control our growth in that area…it's an area that's expanding and we welcome it.'
To meet customer's expectations, robot companies like Nachi are partnering with tooling, power supply and subsystem providers like Daihen (Yodogawa-ku, Osaka, Japan) to make more competitive welding solutions. The resulting solutions are cheaper for the partners to make because they can make several canned welding cells at a time and save on production costs. However, this trend could hurt short-sighted end users in the long run, because while they save on the initial costs, they have to stock a greater variety of parts and supplies and teach maintenance personnel more interfaces. 'About three years ago, people were buying systems based on maintenance and operational costs -- based on what they already had on the shelf. But now, it's price driven and they have to keep more parts on the shelf,' said Tim South, engineer for Custom Machines Inc.
The user's need to comply with standards has added to the customer's demand for greater integration. And as robotic integrators, system and subsystem suppliers face the inevitable challenges caused by new safety standards and the fiscal need to interface components from various suppliers, Robotic Production Technology Inc.'s welding products manager, John Mueller, believes the true beneficiary is the welding cell itself.
'Suppliers are moving toward digital connections between the robot and power supply. The faster communication gives better control and response between welder and robot. Better arc starts, better control, and instead of 15 wires you have one that you can buy from Radio Shack,' Mueller said. 'Systems are moving towards web based and Windows CE so that interfaces look more familiar to operators regardless of the supplier. While these partnerships between suppliers might limit the number of power supplies that a welder can use, the performance of the system is much better.'
Ironically, as robotic systems get easier to interface and gain better control, more customers are putting them as slaves to nearby PLCs - not because it's the best solution but because its what they know. 'Robot suppliers are putting in ladder logic to let PLCs drive the system, even though the robot's more capable,' said Custom Machine's South. 'More people have PLC programming capabilities than robot, so that's where the industry's at.'
So will this extra effort to improve machine-to-machine interfaces and MMI go to waste? Not hardly. As always, when the market crawls out of the hole made by the late 90s, robots will there with a bright, friendly interface and a tightly controlled arc of electricity to light the way.