April 26, 2005

Cowley welding program goes high-tech with computerized plasma cutter

Emily Berniklau (center), a junior at Winfield High School, holds a piece of aluminum cut in the shape of an eagle in flight by Cowley College's new plasma-arc cutter, while Taylor Pingry (left), a senior at Dexter High School, holds the original piece of material. Eugene Robertson, a senior at Arkansas City High School, looks on.

From left, Taylor Pingry of Arkansas City, a senior at Dexter High School; Eugene Robertson, a senior at Arkansas City High School; and Emily Berniklau, a junior at Winfield High School, watch the new plasma cutter operate Monday in Cowley College's Welding Technology lab.

Although the plasma-arc cutting process has been around for about 50 years, the use of computers and design software working with the cutter is relatively new.

Cowley College’s Welding Technology program installed a new plasma cutter this spring, and first- and second-year students are learning to operate it.

Bob Moffatt, instructor, said students would learn how to identify types of material, bring up shapes on the computer and edit them according to size and cutting paths.

“Plasma cutting is cleaner, faster and with less heat input to control distortion,” Moffatt said. “This is high-end arc welding.”

Bruce Crouse, chairman of Cowley’s Industrial Technology Department, said the technology used by Cowley students would better prepare them for employment.

“This is an example of the technology we continue to bring to the Arkansas City campus,” Crouse said. “Students will not only be welding and shaping materials, they’ll be using computers to do this.”

During the height of World War II, the plasma-arc cutting method of welding was developed to improve the joining of aircraft materials. Plasma cutters work by sending an electric arc through a gas that is passing through a constricted opening. The gas can be shop air, nitrogen, argon, oxygen, etc.

This elevates the temperature of the gas to the point that it enters a fourth state of matter called plasma. As the metal being cut is part of the circuit, the electrical conductivity of the plasma causes the arc to transfer to the work.

Plasma cutting can be performed on any type of conductive material, including mild steel, aluminum, and stainless steel.

Moffatt and his students have cut out many intricate designs on the machine, including the outline of an eagle in flight and an American flag. The cutter has the capacity to cut material up to 3/4-inch thick.

“Wired to a computer, the computer monitors the performance of the plasma-arc cutting process,” Moffatt said. “If a company is into cutting multiple parts, they’re using plasma.”

Today, dozens of manufacturers offer portable plasma cutters—some so light they can be carried with little effort. Units are starting to appear with built-in air compressors that make the whole operation fully mobile.

Most, if not all, of the light portable plasma cutters are 110-volt machines that are suited primarily for cutting sheetmetal and other light work. The next level up are the 220-volt machines with 50- to 80-amp output current. These are portable from the standpoint that one person can put it on a truck and take it to the job.

Although the cutting table is four feet by four feet, Moffatt said larger pieces could be cut.

“We have the option of cutting much larger dimensions by pausing the machine and shifting the material,” he said.

The addition of the computerized plasma cutter could clear the way for new areas of instruction. Moffatt said polishing, painting and buffing also would be explored, along with the possibility of working with Cowley’s art and computer graphic arts programs.

“Students will come out of here writing computer programs, where always before it was by hand,” Crouse said. “There are a lot of other projects students can get into. The potential is pretty exciting.”