The art of waterjet cutting

After a year of planning; designing; fabricating; and an around-the-clock, 84-hour installation, "Wake" made its debut in Times Square on July 11, 2018. (Left to right)University of North Carolina-Asheville sculpture student Jeb Hedgecock; engineering seniors Kyle Ward and Kaitlin Thomas; STEAM Studio Director Sara Sanders; and engineering seniors Brittany Hand, Zoe Rorvig, Jacob Fink, and Elijah Nonamaker comprised the installation team. Photo by Adam Taylor.

You wouldn't think a story involving conceptual art and a university-based maker space would have a lot to do with metal fabricating, but you’d be wrong in this one instance. In fact, if your shop has ever thought about expanding its cutting capabilities with a waterjet, you might want to keep reading.

The story begins in 2016 when the University of North Carolina-Asheville's engineering department was in dire need of an expanded workshop. It had only about 1,500 square feet stocked with old metalworking equipment, and the program was expanding, accommodating more students interested in the school's mechatronics curriculum. University administrators recognized the challenge, but also saw an opportunity to address another situation. The art department needed an expanded work area as well, so officials suggested creating a "maker's space," where engineering and art students could work side by side. Heads of both academic departments agreed, made plans for the space, and the STEAM (Science, Technology, Engineering, Art, and Math) Studio enjoyed its ribbon cutting in December 2016.

The studio is located off campus in a warehouse in Asheville's River Arts District. The 12,000-sq.-ft. space is home to a wood- and metalworking shop. Equipment includes CNC mills and lathes, welding systems, a manual plasma cutter, wood lathes, band saws, a CNC router, laser cutter, planer, jointer, wide-belt sander, and a waterjet.

"There are no cubicles or divisions in the shop. We’re hoping that the students actually learn to work together as they navigate the space and to be supportive, giving each other feedback," said Sara Sanders, director of the STEAM Studio and an alumna of UNC-Asheville's engineering program, graduating in 2011.

The students and the studio were challenged in fall 2017 when conceptual artist Mel Chin presented his artistic concept called "Wake." At the time Chin was serving as the Black Mountain College Fellow at the university. (Black Mountain College, founded in Black Mountain, N.C., in 1933, was organized around the principles of holistic learning with the study of art being a core part of a classic liberal arts education. The school produced several noteworthy artists during its 24 years of existence.) The concept called for a re-creation of a figurehead, which was a likeness of the Swedish opera singer Jenny Lind from the USS Nightingale, a 19th-century expedition and merchant clipper that later became a Union warship during the Civil War. The sculpture would be a 24-foot-tall hull of a shipwrecked vessel with the figurehead predominantly displayed. The figurehead also would have animatronic elements that would move its head and chest, replicating the action of breathing. The plan called for the piece to go on display in New York City's Times Square in the summer of 2018.

Sanders said she sought out the engineering department to see if the effort to assist in the creation of the sculpture might work as a senior design project. When she got the OK, the studio was fully committed to making the conceptual art piece a reality.

That's where the waterjet comes into play.

Sanders said that as the STEAM studio was looking to equip its new workspace its industrial advisory board was split as to what sort of cutting table it should get. Half recommended a plasma cutting table, and the other half supported a waterjet.

When it came time to see how the equipment might fit into the 12,000-sq.-ft. area, Sanders said she realized that she’d have to give up some of her welding space to accommodate the table. The waterjet, on the other hand, could fit almost anywhere. That helped to seal the deal.

STEAM Studio purchased an OMAX Maxiem® 1530 abrasive waterjet with a cutting area of 10 by 5 ft. The equipment has an advanced linear motion system that uses digital encoders to provide instant cutting head position feedback to the controller, which helps in the production of precise parts. Students and advisers can use the machine's Intelli-MAX software to design fabrications and create cutting instructions for the waterjet.

Artist Mel Chin and UNC-Asheville sculpture faculty member Matt West verify that the CNC-routed wood cladding mates with the waterjet-cut WT beam. This was the only rib that could fit in the studio. Photo by Sara Sanders

These are some of the lessons that the STEAM Studio has learned from working with the waterjet on "Wake" and other projects:

The waterjet's versatility is hard to beat. "We’ve cut everything from metal to mirrors on there," Sanders said. Because the waterjet stream has abrasive garnet incorporated into it, the jet can cut through various materials, thin or thick, hardened or soft, ferrous or nonferrous, and organic or synthetic. (Of particular interest to many metal fabricators is the fact that the waterjet abrasive stream does not affect the metal material as the cut is made. Unlike thermal processes such as plasma and laser cutting, the waterjet does not have a heat-affected zone.) Each material brings challenges to maintain accuracy during the cut or to prevent too much damage during piercing; the latter wasn't too much of an issue for the STEAM Studio team because they were working with more durable materials.

What has been the most unusual item cut on the waterjet? A nearby manufacturer of water shoes asked the studio to cut several shoes in half. They were going to use the newly cut footwear in sales presentations to show off just how they were made, Sanders said.

A waterjet is good for prototyping. "We were able to use the waterjet for prototyping parts in the beginning with little investment in human resources. As we were figuring out how to mount the wood skirt of the figurehead to the internal truss, we used the waterjet to cut 1/8-in. steel strapping to fasten to the inside of the wood shell. We also were able to quickly cut parts for fixturing and rigging," Sanders said.

The waterjet saves time in the early stages of a project with its accuracy. The majority of the flanges were cut on the equipment, which minimized errors in hole spacing and ensured mating flanges had identical hole patterns where connections were not square, Sanders added.

It helps to introduce new operators to the waterjet in a holistic way. In the Introduction to STEAM class, a freshman-level course, students get a chance to use the waterjet on one of their projects. The students are asked to create a metal shadowbox that involves cutting angle iron and fabricating the box by welding it together. The focal point of the box is a design that is cut out of 1/8-in. aluminum on the waterjet. The students draw the design, use the Intelli-MAX software to trace it out and create a program, put it on the thumb drive, plug it into the waterjet's control system, fixture the aluminum blanks, and cut out the design.

"Technically they aren't ready to operate the waterjets, but it gives them exposure to understand what needs to happen to cut a part," Sanders said. "That's the first step we take to make it more accessible."

Good water is good news for the waterjet cutting machine. As part of a waterjet installation, a water quality analysis should be done. At minimum, the quality report should cover total dissolved solids (TDS), silica content, and pH value. TDS is particularly important; the lower the score, the better the internal workings of the waterjet perform.

As part of its purchase, Sanders said that OMAX provided free analysis of the water.

"It came back that we had some of the best water that they’ve ever seen," Sanders added. "I guess that's why we have all of these breweries moving here."

The final touches are put on "Wake" before its official debut. Photo by Adam Taylor.

Obviously, the STEAM Studio is not running the waterjet as a job shop would, so it's not putting as much stress on the internal seals and tubes. Sanders said maintenance tasks are limited to a couple of times per year, a schedule that would be more frequent in a production environment.

The waterjet can do more than just cut. Sometimes it helps to label fabrications if they are part of a large assembly.

"The waterjet was ideal also because of the scribe feature," Sanders said. "Where each rib half comprised four to five pieces of steel, we were able to label each piece. We also were able to scribe mating profiles onto the parts. Where complex angles came together on flanges, we had the profile scribed where the part got welded on. This saved a tremendous amount of time in the layout, fixturing, and welding processes."

Material handling always needs to be part of the conversation when it comes to any capital investment. STEAM Studio recognized that it wouldn't be using its waterjet like a manufacturer would. As a result, not much thought was given to some sort of material handling device, such as a jib crane.

"Wake" challenged them in a way that they had never experienced before. The team had no lift truck, so they ended up moving 25 sheets of ¼-in. plate and six sheets of 3/8-in. plate by hand—six sets of hands, to be exact. Incorporating plate occurred only after a change in the original design.

"So we had to have all of the design drawings stamped by structural engineers in New York City, and we worked with them closely on the design of it. Initially we had the ship's structure bolted into an I-beam base, which was really a grid of I-beams. The same support was specified for Jenny Lind as the figurehead," Sanders said. "So we asked, ‘Hey guys, can we figure out another way to counterweight this because we cannot handle I-beams that heavy.’"

The engineers had specified the I-beams for their weight only because the whole sculpture was freestanding. The art piece couldn't be anchored into the street because it was a public thoroughfare.

Sanders said Mountain Steel Co., the studio's Asheville-based steel supplier, was very helpful during the project, particularly when it came to moving the pieces to a parking lot on campus where the sculpture was pulled together before being disassembled again and shipped to New York.

One of the final obstacles that Sanders and the team faced with "Wake" was the need for all welds to be made by certified welders to meet New York City code. Unfortunately, finding welders with the appropriate certifications and capable of delivering the structural welds that would stand up to the examination of a certified welding inspector (CWI) wasn't easy in North Carolina, which doesn't mandate the use of certified welders for such work.

The STEAM Studio team finally found someone to do the welds, and an inspector from New York City came down to conduct ultrasonic and magnetic testing. With the CWI's passing grade, the sculpture was ready to be delivered to the Big Apple. To that point it was going to be the largest sculpture ever to grace Times Square.

Steel strapping and mounting tabs were cut on the waterjet to fasten the wood skirt to the steel truss that made up the internal structure of the Jenny Lind figurehead. Photo by Sara Sanders.

"Wake" was unveiled on July 11, 2018, after three days of around-the-clock work. It was paired with "Unmoored," a digital augmented-reality work Chin created in collaboration with Microsoft. With both art projects working in tandem, a person could look at "Wake" and imagine that it was taking off skyward, joined by a flotilla of boats floating above Times Square because it now was covered by the rising seas.

"Wake" was on exhibit in Times Square until Sept. 5. It's been in storage since then, but it might be making another appearance in another major city in 2019, according to Sanders.

In the meantime, engineering and art students are using the STEAM Studio to learn just what it takes to make designs a reality.

"It's been fantastic," Sanders said. "We’ve had a lot of positive experiences with the informal collaboration that occurs in a project such as ‘Wake.’"

The studio also has been able to put the waterjet to use when school is not in session. For example, the waterjet was used to cut geodes for the UNC-Asheville geology department. It's just one of the things you do with a waterjet: You put it to work.

Joshua Swainston, content marketing writer, OMAX Corp., contributed information to this story.

STEAM Studio, UNC-Asheville, https://steamstudio.unca.edu

OMAX Corp., www.omax.com