Above: Able to bevel parts during the cutting operation, the True Hole-capable MasterGraph Ex2 banishes the need for secondary processing.

Engineering plasma cutting technology to provide quality, accuracy and speed for every job

February 2016 - Golfers dream of hitting a hole-in-one. So how hard is it? For an amateur the odds are one out of every 12,750 swings. Statistically the elusive shot is most likely to occur on a par-3, the shortest hole on the golf course. Par-4 and par-5 aces are rare. Until recently, plasma operators looking to cut “holes-in-one” in mild steel plate without secondary operations, like drilling or reaming, found the task equally tricky. 

“In the last five to 10 years the need for bolt-ready holes, better edge quality and faster cutting speeds has driven our industry,” says Timothy Joslin, cutting machine product manager for Koike Aronson Inc./Ransome. Using plasma to cut holes was long plagued by two primary issues: One, poor edge quality invariably resulted in a ding or divot along the hole’s edge, making it susceptible to stress fractures; two, taper was subpar because the top of the hole was often wider than the bottom, missing tight tolerances. 

“Then Hypertherm’s True Hole technology entered the plasma industry.  Enabling Koike cutting machines “to support the technology’s HyPerformance Plasma HPRXD auto gas system,” says Joslin, “forced us to upgrade our electronics because machines equipped with True Hole have to run faster and with greater accuracy. It also prompted us to take machine design in a different direction.”

The Klean Sweep slag removal downdraft table moves debris into a pit or raised discharge pan while the plasma machine continues to cut.

Press ‘go’

“Approximately 70 percent of the cutting machines we sell now are True Hole capable,” says Joslin. The software powering the equipment has also improved. For example, “the task used to require an operator highly skilled in programming the machine and cutting parts. Now True Hole looks at the hole area and applies values that are predetermined by Hypertherm. This makes it easy for the operator—regardless of skill level—to program and run the machine. The operator checks to make sure he has the right consumables, lines up the plate with the controller and presses ‘go’.  The result is bolt hole quality produced automatically without operator intervention.”

Programming, software and a CNC control work together to maintain the right position of the plasma arc to ensure the accuracy of the surface cut. The partnership between Koike’s cutting machines and True Hole isn’t surprising when you consider Koike’s track record. 

For more than 90 years, Arcade, New York-based Koike has designed, engineered and built metal cutting, welding and positioning equipment for service centers, heavy equipment, general fabrication, energy, shipbuilding, pipe and vessel, transportation, education, construction, tank fabrication, repair and maintenance, and other industries.

Big and strong

Koike machines are not one size fits all. The Plate Pro Extreme provides dual side drive, plasma/oxy fuel cutting that is fast, accurate, versatile and durable. It’s a mid-range machine that can cut plate up to 4 inches thick and 10 feet wide. The Master Graph Ex2 is True Hole capable. It can accommodate multiple plasma/oxy fuel torches and perform bevel cutting. 

Koike designed the Versagraph Extreme to do the heavy lifting at shipyards, service centers and heavy equipment manufacturers. The machine’s cutting area can run from 16 feet wide to 30 feet wide and up to 300 feet long. 

The Koike machine produces bolt hole quality automatically without operator intervention.

“Lately a growing number of manufacturers want to get into high-definition plasma cutting but they have a small budget,” Joslin notes. “To help meet that need we’re building a cost-efficient dual side drive machine that has True Hole technology and can run as a plasma or accommodate both plasma and oxy fuel.”

The new product, called Plate Fab, has a unitized design and it has already attracted a customer that builds farm implements. “The machine is suited to the needs of small general fabricators but it can also support a manufacturer that is growing its business and has exceeded capacity,” Joslin says. “Plate Fab is the next step up.”

While Plate Pro Extreme and Master Graph Ex2 continue to attract the largest customer following, Koike uses customer feedback to make additional improvements to its popular models. “Time is money,” says Joslin. “We have targeted speed and accuracy to push production to new levels for customers. And we build our equipment to last.”

Reveling in bevels

Plasma beveling is another trend Joslin has seen gain traction in the last three years. “We’ve sold over 100 units of the 3D-LT full contour plasma bevel unit,” he says. “Ninety-nine percent of the time the need for weld preps is what dictates a requirement for beveling steel.”

Like hole-making, plasma beveling often proves a tough task for those shaping metal. “Typically an operator would use a machine to cut plate, then lift this large rectangle off the plasma cutter and either hand grind or use a hand-operated nibbler to put an angle on the material. Operators could also use a track torch to trim desired angles,” Joslin explains.

From luxury liners to general fabrication, Koike engineers plasma cutting machines to fit the application.

Since the Master Graph bevels parts during the cutting operation, the need for secondary processing disappears. Finished parts are accurate to size. “A good weld prep is critical especially in applications like tanks,” Joslin notes. “The manufacturer rolls plate into large cylinders that have to be welded along the seam. This process is often performed by a robot. If there are any errors in the weld prep the robot will follow that, so it has to be perfect.”

In addition to plasma cutters, Koike also engineers cutting tables. Water tables offer one method for use with plasma cutters. Koike designed a downdraft table that is self cleaning. “You can have two to three days downtime while the operator manually cleans the [water] table,” Joslin says. “With our self-cleaning table, a bar scrapes the table bottom and moves debris and dirt into a pit or raised discharge pan while the machine continues to cut. When the pan gets full from either the pit or raised discharge  table, the operator can dump it. There’s no downtime.”

Like other developments, the self-cleaning table was designed in response to customer feedback and is especially efficient for shops with heavy workloads where stopping production to tackle large clean-up jobs can put a dent in a company’s bottom line.

“We are always listening to our customers,” says Joslin. “We want to be able to anticipate what they need and then implement that feature or function on our machines. Their feedback and our ability to adapt to it is how we continue to grow. We keep our engineering department busy.” MM