This information was condensed from an article by Tim Heston, The Fabricator, February 2014
Laser photonics, pragmatism and Directed Light
How Directed Light carved a niche in quick-turn laser fabrication
Directed Light, a 30-year young enterprise, has evolved into a diverse laser prototyping and short-run production operation. Kudos to Neil Ball, leader of this 25-member troupe. Ball has encountered a variety of project and purchasing managers from companies, like Boeing and Apple, who expect their fabricated order to be on its way when the PO has been signed. But Ball knows what these companies, and others–like Applied Materials and Medtronic–really want! And Directed Light has it. This shop, with its 17 workstations, covers the photonics spectrum. Directed Light has a lot happening at its facility: ablation using UV lasers, drilling filters for complex microfluidics applications for aerospace using fiber lasers, alongside are medical device welds being made with a YAG or dental X-ray film being cut with a CO2. At Directed Light, it is all lasers, all the time!
Ball prides his approach to pragmatism. He may be drawn to some of the cutting-edge lasers, such as the newer ultrashort-pulse picosecond and femtosecond lasers—but the high purchase cost and slow cycle time would not make these a good investment for the business. Directed Light displays its commitment to practicality—it has a workstation with the frame of an old Bridgeport mill, retrofitted with a low-power YAG, which can be applied to cutting or precision heat-treating or laser welding (see Figure 1). Most importantly is how quickly the workstation can switch between processes. High-tech meets old-fashioned strength and sway.
Ball’s background underpins applying that old-fashioned strength and sway (sometimes called hard work). “I started sweeping the floors in this industry,” declares Ball, allowing for a lasting impression with his Elvis-like sideburns and penetrating scrutiny. Ball worked in a job shop in Silicon Valley some decades back. He has done it all: putting together and maintaining compressed air lines; operating sandblasting equipment, deburring parts, performing electropolishing, and learning machining. He strengthened his hands-on knowledge and, by being on the ground floor of the personal computer entry to industry, he gained computer experience with some high-end processing. Ball believed if he learned the technology, he would be employable for the rest of his life.
The job shop purchased a CO2 laser to cut tubular components for oscilloscopes. They needed a swing-shift operator and Ball volunteered. He had the CNC machining experience that was the right match for the new laser’s multiaxis system. And Ball loved it. “To me, it was a heck of a lot easier to program a laser than a machining center…. You could set stuff on fire.” That observation was closer to the truth than he realized. An early challenge for Ball and his team was to weld components for explosive materials without exploding the fabrication. Laser welding was the optimal choice due to its narrow heat-affected zone (HAZ) and controlled heat input. The team set up blue ice and copper heat sinks, installed a barrier (made of 1-inch thick Lexan™) and, in fact, did create a few explosions.
For the next several years, Ball continued working at the Silicon Valley job shop–gaining experience with laser processing–including parts for pacemakers and defibrillators. Next, he moved to a large contract manufacturer that had several government contracts, which included producing inertial guidance packages, accelerometers, and other components for a variety of applications that ranged from maverick missiles to oil drilling platforms. The diversity was exciting but the inefficiencies (particularly with government jobs) was grueling. About that time, he made the move Directed Light, a small company with the quick tempo in which Ball thrived.
Ball started in systems integration at Directed Light (developing applications, installing machines, and training customers). In due course, he went over to sales. Ball comments, “I found I could talk to customers and not scare them off.” Now capturing the processing and sales experience to solidly ground him for the role, he became general manager. Today, he is president.
Ball had learned that being in the parts business offered a broad view of the industry. He could determine what was hot…automotive, aerospace, or medical devices. Using the information garnered through the parts business, Directed Light had market intelligence that opened the door to expansion. Another shift that occurred is the shutting down of systems integrations, albeit is still operates a parts division. The job shop division has experienced substantial growth and allows for the competencies to address a variety of operations, such as laser sintering to repair molds or impellers for the chemical business to microwelding for hearing aid components.
Figure 1: This model of the company’s flexible laser station uses the frame of an old Bridgeport mill.
The Quick-turn Method
The first question Ball and his sales team poses to new customers is whether the application is suitable for a laser. They discern if the part can be stacked and cut in batches—because if that is true, perhaps wire electrical discharge machining (EDM) is a better choice. Some parts may want the waterjet process as it is more cost efficient. Directed Light determines if the laser is the most cost-effective process with which to begin. If not, proceeding further would be a waste of time and money, for the customer and Directed Light.
Of course, when a job does fir the laser, the development and planning begin immediately. Ball and his team of engineers can determine what is required. For example, if a microweld seam might be needed to join two different materials, the team will determine melting points to insure precision welding by controlling heat. Ball knows that any impurity can be detrimental and that the laser will vaporize whatever has the lowest melting point. The goal is a joint design that is laser weld-friendly that will fit with no gap. After the process plan is in place, Directed Light will either produce the part in-house or transfer the setup to the customer’s own facility for ease between transition and production..
The “Top Hat”
Directed Light has also evolved into a quick turn-around shop for specialized applications that often involve very small workpieces. The shop’s highest-power system is a 1-kW CO2 laser, and few applications require more than 600 W. (Though not all parts are small; for one laser sintering job, the company repairs large impellers used to mix chemicals to make pesticides.)
The lasers can process an extremely small workpiece successfully–but holding that workpiece steady during the various laser processes (drilling, cutting, heat treating, or welding) is not straightforward. When you’re cutting something that’s smaller than the width of a human hair, how do you hold it? Technicians have relied on vacuum chucks and various styles of parts catchers, or microtabbing the part within a larger parent material. Regardless of the method, it isn’t standard workholding.
Ball described one Boeing job that entailed a tiny, 17-4 stainless steel, top hat-shaped part with tiny holes between 0.0180 and 0.050 in. in diameter. “Imagine the Planters Mr. Peanut’s top hat and shrinking it to a rice kernel.”
Laser-drill holes with diameters between 0.0020 and 0.0030 in were required. Although the laser can drill these with no trouble, how does the part remain steady? Engineering technicians created a tiny mandrel with reliefs machined into them, which ensured this bit wouldn’t fuse to the workpiece during the drilling process. Technicians took just about a week to develop the process needed to weld the tiny top hat part.
Directed Light and its goals require quick thinking and shop floor pragmatism. No “ivory tower” engineers need apply—Ball wants people who “learn by doing.”
As noted above, Ball himself got into lasers through manufacturing (not academics)—specifically, experience managing CNC machine tools. Ball not only wants a person trained as an engineer, he also wants that individual to how to work a caliper and read a micrometer.
Many candidates that arrive at Directed Light come from hands-on environments, including California Polytechnic State University. “The school’s motto is ‘Learn by doing,’” Ball added that this approach overcomes one of the principal obstacles with the skilled-labor problem. Manufacturing needs smart, engaged people; but those people need to be engaged in shop floor realities, not just software. According to Ball, just because a person can draw it, doesn’t mean he or she can make it.
Ball openly admits that the lack of available talent, even in a place as engineering-centric as Silicon Valley, continues to be its greatest trial. The company is also expanding its candidate pools, such as hiring individuals out of the medical device industry to integrate with the shop’s experience in that sector.
Primarily the company focuses on thinking on its feet. Ball said, “We can’t wait on tooling. If the tooling isn’t here, we have to improvise with [toggle] clamps, magnetics—even double-sided tape,” Ball said. “LEGOS® have been a new favorite tooling choice for us.” The shop uses custom tooling for production work, which is contracted out to local machine shops. But for the initial prototype, Ball and his team think fast as well as pragmatically.
Laser processing is incredibly precise. However, when technicians are building a prototype, and the deadline is looming—that is when laser photonics meets shop floor pragmatism—and it may well be with LEGOS.