Cutting through the clutter
October 1, 2006
While HVAC and plasma-cutting technology may seem synonymous today, the world of metal fabrication has long been jumbled with a variety of processes.
Often overshadowed by laser and water-jet cutting systems, plasma technology was viewed by many manufacturers as limited at best.
However, plasma-cutting systems are experiencing a revival of sorts.
Fabricators across the country are coming to realize the high performance, cost-effective benefits of tried-and-true plasma-cutting technology.
When it opened in 1968, Spartanburg, S.C.-based Keller & Son Industrial Contractors Inc. was operating out of a 5,000-square foot facility. Today, they have burgeoned into a 100,000-square foot operation that runs seven days per week and has 40 employees.
Over time, the company assumed more custom metal-fabrication work in addition to its millwright and plant-relocation services. Today, more than 75 percent of their focus is on manufacturing. It was an evolution made possible - and profitable - through an investment in technology.
"We have changed from a sheet metal fabrication facility that outsourced into a competitive manufacturing business," says Trent Keller, company vice president.
The evolution began when the company landed a large job and had only three months to find a way to handle it. They considered outsourcing, but it was cost-prohibitive and time consuming. Keller also looked into water-jet or laser-cutting technology, yet these solutions had drawbacks.
Keller needed a system that was accurate and powerful enough to cut mild steel up to 2 inches thick. They also wanted a system that was easy to program and operate and that demanded little operator training. After much research, they decided on the Vicon 2001 plasma-cutting system from Plasma Automation. The machine would include an Innerlogic 200 AMP high-density plasma power supply and ViSoft cutting system software. The system was delivered within nine weeks in 2002 and was up and fully running in less than three days.
The choice may not seem surprising, as plasma-cutting technology has maintained a well-defined niche in the manufacturing since the 1950s. Keller says he saw that his initial investment was reasonable, that operating costs were moderate, and that a machine can run for years without the need for expensive overhauls or replacement parts.
Aiming ‘high'What may be viewed as unexpected, however, was Keller's decision to purchase a precision "high density" plasma system. The choice granted him something that has remained elusive to most manufacturers for decades: the "mythical" union of affordability and performance in one machine tool.
"We have realized a tremendous increase in part accuracy and repeatability with the Vicon 2001 as compared to our original plasma-cutting system," says Keller. "We can match a part from today's run to another processed yesterday, and they are absolutely identical. We have achieved a level of tolerance that we never expected."
In response to a demand for more capacity, they purchased a second machine in January. It was a Vicon Elite plasma-cutting system with a 10-foot-wide by 20-foot-long cutting table and an Innerlogic 260 AMP high-density plasma power supply.
Most of the tables Keller looked at prior to purchase were 8 feet wide, so the Elite's extra width has been a nice differentiator for the company.
"We are the only manufacturer within a 100-mile radius with such a wide cutting area. Our customers are continually amazed when they see it," Keller says.
FlexibilityThe larger table offers processing flexibility and the productivity advantages of a shuttle table as two standard-sized sheets of material can be placed on the machine simultaneously. After the first sheet is finished being processed, the gantry quickly moves the plasma-cutting torch to the opposite end of the table to cut the second piece of material. The operator is then free to unload the finished parts while the machine is still processing.
"We have far more production time with this machine. It has been a real asset," Keller says. "Whereas it may have taken us a full day to build one structural wall, for example, we now are building three to four walls per day. We are more competitive and efficient than ever before."
The high-density plasma power supply, coupled with the machine's rigid frame, has created its own set of advantages.
"We now achieve exceptional repeatability," explains Keller. "We need to provide our customers, especially machine shops, with parts that are highly accurate and similar run to run."
The new machine, with its higher amperage, has enabled Keller to control edge quality and part tolerance. It also can pierce materials on the fly more than an inch thick.
"On our original plasma table, if we needed to cut a hole in the center of a piece of plate material, we would have to lead into the hole from the edge. Or we would have to use a drill bit to pre-drill 50 percent of the hole before processing. Now, we burn multiple holes easily, quickly and accurately," Keller says.
Part qualityWhen asked about part quality, Keller reaches behind him and places a cut part made out of 1.25-inch mild steel on the table.
"This part has come straight off of our Vicon Elite table without refinishing," he says. "Not only is it accurate, but the edges are smooth without a drop of dross. Nine times out of 10, the parts that come off of our table look this way.
"Customers today are not only looking for tight tolerance and fast turnaround, they also want their parts to be smooth and to look nice."
Before the high-density cutting systems were installed, workers had to spend time refinishing every part. There was also the risk of marring or damaging the part in the grinding process. The new technology eliminated the refinishing step from their manufacturing process, saving time and labor.
"No matter what the thickness, when we take a part off of the Vicon, 90 percent of the time, we do not have to do any refinishing," Keller says.
Keller & Son has also handled work from customers that have laser-cutting machines. This is partly because, in terms of edge quality on a plate part, your eyes must virtually strain to discern the difference between the two technologies. It is also because when materials approach 1 inch in thickness, it is more cost effective to use a plasma-cutting system, Keller says.
ProductivitySince installation, Keller & Son has realized a 70 percent increase in their overall productivity.
The Elite's ability to mark or pierce a bend point on a part has helped streamline the process. Previously, the team would have to cut a pattern out of thin galvanized steel, place it upon a given part and mark or "prick" the bend line by hand for the press brake operator. Keller explains that this would guide the operator to prevent the hydraulic press brake's automatic backstop from getting knocked out of square by an incorrectly placed part. Now, they program the bend lines directly into the ViSoft cutting-system software and the plasma table simply marks the part automatically.
The system's Windows-based software has provided Keller with enhanced processing capabilities. Plasma Automation designed and programmed the ViSoft software, something that has helped simplify training and phone support for the company.
"If you have a question, whether it is about the table or the way in which it is handling an application, you only need to call one company," Keller says. "Because the manufacturer has intimate knowledge of both the software and the cutting system, solutions are found much faster and with far less effort. This saves us an incredible amount of time."
With this software, they can program parts either at the table or in the engineering department.
"For basic nesting, the program does really well," says Keller. He estimated that the software's nesting capabilities have reduced the facility's material waste 15 percent to 20 percent. In addition to the system's cutting speed and large table size, the software has increased the company's actual processing time considerably. It has also expedited order fulfillment.
When handling industrial contract work on location, Keller has drawn a needed part and faxed the illustration back to the facility. His programmers would then input the dimensions into the cutting software. Programming was so quick and easy that his staff could program, process and ship the part out to him that day.
"We like the software very much because it is really easy to use, and the system and software work together so well. It is so user-friendly that we can train people to use the plasma-cutting system in less than one day," Keller says.
This article and its images were supplied by Plasma Automation Inc. and AMH&E Marketing Communications Inc.