Waterjets Take Up Residence at Laser House

By: Brad Kuvin

Monday, June 1, 2015

Until 2009, the cutting machines residing at Central Cal Metals, Fresno, CA, performed laser cutting—25 machines in all, working alongside complimentary fabricating equipment including press brakes and shears. When business at the third-generation family-owned company levelled off somewhat in 2008, the company welcomed a waterjet-cutting machine into its sprawling 165,000-sq.-ft. home.

Waterjet cutting has opened numerous doors in several new markets for Central Cal Metals, including cutting reflective materials such as aluminum (shown here), as well as cutting nonmetals such as plastics and rubber.
“We conducted a lot of research into waterjet-cutting technology,” says operations manager Tom Alandt. “We visited several equipment suppliers and brought along sample parts that we asked them to cut, on the spot. We watched how they programmed the parts, and how the machine cut them. And, we asked each supplier to cut the same part profiles from a variety of material types and thicknesses.

“In 2008, when we began researching the process,” Alandt continues, “we believed that the worst-case scenario was that we’d be able to use a waterjet-cutting machine to cut thin-gauge aluminum. But within a year of installing the first machine (from Flow Intl.), we realized the potential, and we purchased a second Flow machine.”

Much of the early work for its waterjet-cutting machines, says Alandt, was for existing customers. Atop its customer list are manufacturers of automotive-aftermarket parts and suppliers to the aerospace, farm-equipment and electrical industries.

Now six waterjet machines, all Mach 3 models from Flow Intl., live here.

“While we experienced consistent growth in our waterjet-cutting business from the outset,” says Alandt, “since 2012 waterjet cutting has opened doors into several new markets. For example, the technology’s unique capabilities, including cutting reflective materials as well as nonmetals such as plastics and rubber. And, with zero heat-affected zone, we have been able to grow significantly into the aerospace industry. We’re even cutting rubber for the farming industry.”

And, farm-equipment customers for Central Cal Metals’ laser-cutting services now turn to the company to waterjet-cut thick mild-steel plate.

No Lot Size Too Small

When the economy changed in 2008, so did many a job-shop fabricator, including Central Cal Metals.

“We used to accept only orders for 50 parts or more,” says Alandt. “When business slowed in 2008-2009, we decided to wave that restriction and started taking on smaller lot sizes. And we’ve found that waterjet cutting really lends itself to that business philosophy, especially for cutting thick work. The combination of being easy to program and set up and having longer processing times than laser cutting allows the waterjet-cutting machine operator to walk away from the machine while it cuts and tend to other machines.”

Central Cal Metal’s initial foray into waterjet cutting comprised a 6.5- by 13-ft. Flow Mach 3 4020b Dynamic machine. Then it added a larger-format machine (6.5 by 24 ft. Model 7320b Dynamic), “to better complement our 20- and 30-ft. press brakes,” says Alandt. “That large machine brought in work we previously had to turn away, such as cutting large conveyor rails.”

Today the waterjet area of the plant houses four of the smaller machines and two of the 24-ft. machines; all employ 94,000-psi pumps as well as all of the Flow bells and whistles. These include three-side loading with four-sided operator access; the Paser 4 cutting head that enables orifice-assembly changeout without having to replace the entire cutting head; and the FlowNest programming software that features scrap remnant control.

Adjusting to smaller lot sizes has led to other operational changes.

“We’re stocking more material types and plate sizes than we had in the past, and we’re doing more quoting,” Alandt says. “And we have to be aggressive—and accurate—on pricing. We upgraded our quoting process to take a more scientific and mathematical approach.”

Stack Cutting and Other Unique Jobs

Integrating waterjet cutting into its operations came relatively easy to the Central Cal Metals team, Alandt says. But the learning curve and real trick to optimizing the return on investment has come with learning to handle the complex and challenging jobs that come in the door.

One technique the firm has become quite adept at is stack cutting, to optimize throughput. “We can stack large, heavy work,” says Alandt, “to cut two parts at a time. We’ll typically stack material 16 to 7 gauge thick, provided the blanks are larger than 12 by 12 in. With smaller work there’s a chance vibration could impact cut-edge quality and accuracy.

“We also quote a lot of odd-shaped and difficult profiles that require precise positioning under the waterjet head,” Alandt continues. “We’ve even brought in parts that were previously and incorrectly cut by other shops, and we were able to salvage the work.”

Alandt cites one example of such a job—a 3-in.-thick steel part measuring 14.5 in. wide by 96 in. long. The customer needed ½ in. trimmed from the entire length of the part.

“Waterjet cutting proved the perfect process for this job,” he says, “but it challenged our operators in precisely positioning the part under the cutting head. With the part positioned, we then set the machine to low pressure and switched off the abrasive, to etch a cut line to check alignment before cutting.”

For another unique job, cutting stairway railings from ½-in. hot-rolled steel for an architectural firm, “the customer wanted very sharp corners,” says Alandt. “While we could have laser-cut the parts, heat buildup in the corners would have required us to round the corners, which would have been unacceptable. Waterjet cutting allowed us to cut the sharper corners.” MF


See also: Flow International Corp.

Related Enterprise Zones: Fabrication

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