Being able to provide its customers with complete assemblies has created a competitive advantage for Ridgeview Industries of Grand Rapids, Michigan. With the help of new arc welding robotics, this 34-year-old company can now deliver a turnkey operation with all stampings and welds being done in-house. Previously, Ridgeview would either outsource or use semi-automatic systems for the 20 percent of its business that required welding. However, outsourcing created additional delays and loss of control; while in-house, semi-automatic systems limited production volumes and the company's ability to perform difficult, out-of-position welding.
The solution to its problems became apparent two years ago when Ridgeview Industries turned to The Lincoln Electric Company for welding expertise. Lincoln Electric recommended the Power Wave® pulsing inverter power sources in combination with FANUC robotics. Since installing these units, Ridgeview creates high quality welds in-house for its automotive and furniture industry customers. Being able to provide a high technology, robotic package in its manufacturing process not only pleased current customers, but also impressed new prospects leading to the company winning new business that may not have been possible before.
Ridgeview Industries, a 370-employee firm, now has a total of 18 arc welding robots - some work independently while others are multi-station units working in assembly line fashion to complete intricate parts. These robots handle applications from brackets to mountings for GM, TRW, Shape (which supplies to Honda and Mitsubishi) and Meridian (supplier of Ford) as well as some of the more prominent office furniture suppliers including Haworth and Herman Miller.
Kirk Briggs, Manufacturing Engineer at Ridgeview Industries explains why it was critical for the company to expand into the robot welding business. "Our customers were demanding that we provide not only stampings, but completed assemblies," said Briggs. "It was not feasible for us to do this with our semi-automatic systems because so much of the work was out-of-position or required multiple welds per part. We were also having a difficult time finding skilled welders to perform this type of work."
Both Briggs and his colleague, John Doneth, a Welding Engineer with Ridgeview Industries, had experience with Lincoln Electric robotic systems from previous employers, so they knew exactly where to turn when the question of robotics was raised.
"The reasons we chose Lincoln equipment are the ease of integration with the FANUC robot, the excellent support available for the system and the user-friendly programming," noted Briggs. "The robot is basically plug and play - it comes ready to go. It has been my experience with other robotic systems that it is a bit of a struggle to set them up."
Two Jobs, Two Different Applications
To demonstrate the scope of jobs performed at Ridgeview Industries, we will examine two product lines. The first is the motor mount line, which Ridgeview gained when another stamping company was doing a very poor job of welding these mounts by hand. On this line, Ridgeview produces parts for R.J. Tower with ultimate use in Dodge vehicles. The part requires two fillet welds to join two pieces of steel. The one robot dedicated to this job is able to make one part every 25 seconds, laying down 12" of weld metal. With the use of a turntable, an operator is able to load the stampings on one side of the table while the robot simultaneously welds on the other. The cell utilizes a Lincoln Electric Power Wave 450 and a FANUC 100i robot.
Another robotic cell, which produces hitches for the Ford Expedition and Lincoln Navigator through Meridian Automotive, is Ridgeview Industries newest robotic cell producing a part with 72 inches of weld in 90 seconds with a total volume of 250,000 parts per year. To complete the hitches, two robotic cells, each outfitted with dual robots, weld 10 stampings to create one part. A number of different joint configurations are required on the 26 total welds for this part including fillet, lap and butt welds.
The hitch line cell also uses a FANUC 430if material-handling robot to move the parts from one robotic station to another. In addition, a Genesis ferris wheel turntable indexes the parts to the Power Wave 450 power sources and FANUC 120i robots to further automate the system. One operator loads parts on one end of the cell while a second operator unloads the finished parts.
A Total Package Approach
According to Doneth, the ability to complete a total customer package under one roof has been a real plus for the company. "We've been know for our excellence in stampings for quite some time, but now we are making a name for ourselves with our robotic welding capabilities. What we are finding is that we are able to offer what our competitors can't - presses that range from 200 to 1,000 tons, plus high-volume, high-quality welding thanks to our robotic systems," said Doneth.
Briggs is also enthusiastic about the in-plant capabilities afforded by the cells. "The robotic welders provide excellent accuracy and consistency, even on hard-to-weld parts," explains Briggs. "We really like the Power Wave power sources, they've been an excellent machine, very easy to set up and integrate. They are user friendly in being able to switch welding schedules or to switch wire. We've been very happy with them and have experienced no downtime in two years."
In addition to the power sources and robotic arms, each cell is outfitted with Lincoln wire feeders and Tregaskiss guns. The robots can handle jobs that require part manipulation and intricate welding that would be difficult to achieve with semi-automatic welding. All of the welding wire is Lincoln L-50™ in diameters that range from .035" to .052". Shielding gas is an argon/CO2 blend. According to Doneth, most jobs have to be welded to exacting customer specifications derived from American Welding Society requirements.
Because of the variety of jobs performed by Ridgeview Industries, the 120 ksi, high-strength, cold-rolled steel can vary in thickness from 1 ½ to 9 mil. While some lines have dedicated robotic welding units because of high volumes, smaller volume jobs may share one robot. A simple change in tooling will allow one robot to accomplish a number of different parts.
Set-Up and Operation
Because the systems are so easy to operate, Ridgeview Industries is able to find people with limited welding experience and quickly train them to operate the cells. Four welding technicians are responsible for the overall, day-to-day operations and programming of all the robotic cells.
Installation of new systems is handled by outside integrators such as Genesis and Combine Tool & Die. These companies build the tooling and complete the design package before it is delivered to Ridgeview Industries factory floor. According to Briggs, once the units arrive at the company's door, they are ready to work".
Service and Training
"We have been very pleased with the service that we receive from Lincoln," said Briggs. "Representative Brian Hillier is available to us anytime. Most of our day-to-day contact is with Paul VenCato from our local distributor, Miller Welding Supply. Paul actually knows how to program the robots and is very good about helping us set-up and change parameters. If we have any questions, he is always readily available. And, if there is something he doesn't know, he is on the phone right away to Lincoln's headquarters in Cleveland to resolve any problems in a matter of minutes."
Ridgeview Industries personnel have also taken advantage of the robotic training offered by Lincoln Electric. According to Doneth, they spent a day at the Automation Division headquarters learning how to best utilize the powerwave® and fanuc robot.
After seeing the value that welding can bring in offering customers complete assemblies, Ridgeview Industries hopes to add more welding capabilities in-house. With our growth in welding we are also utilizing some of the Engineering capability's of Ferris State University in the development of some of our new projects. Since the company will soon be opening a new expanded facility, there should be plenty of room for growth.