Automation: The key to cost control

Metal fabricators got a quick history lesson before technical presentations on automation at Mazak Optonics' open house event in Elgin, Ill., in mid-June. As with any look back, it gave everyone a better idea of what the road ahead may look like.

Historical fact: While millions of U.S. citizens used to be employed in agriculture at the turn of the 19th century, today only 1.9 percent of the working-age  population is needed to grow food for this country and the entire world. Lesson learned: Just because fewer people are farmers doesn't mean this country has no farming. The same scenario applies to manufacturing, which many people incorrectly assume is disappearing from the U.S. at an alarming rate.

Historical fact: Since 1987 factory output in the durable goods sector has risen 160 percent while employment decreased 20 percent. Lesson learned: Fewer people are needed to maintain record-high productivity in today's manufacturing facilities.

Historical fact: While the unemployment rate still hovers around 9 percent for the general population, it's about 16 percent for those without a high school diploma. Lesson learned: Manufacturing isn't absorbing these under-educated people because these companies need an educated workforce to operate sophisticated equipment.

What's the theme connecting all of these points? Automation. Machines now do many of the jobs that unskilled labor used to handle. As more investment has been made in this area over the years, productivity has skyrocketed, and the ranks of those employed in manufacturing facilities has decreased consistently.

Bill Citron, Mazak Optonics' president, said at the open house that investments in automation won't end anytime soon. Manufacturing in the U.S. always has room to improve.

"The great misnomer of manufacturing is tracking the takt time. What should be tracked is the time it takes to create the entire assembly," Citron said. "At the end of the day, that's what the fabricator gets paid for."

For fabricators, that means the laser cutting equipment and other nearby support machines need to be working with metal parts. Any time used otherwise is not making the fabricator money.

"When you are making sparks, you are making money. When you aren't, you aren't making money. It's as simple as that," said Keith Leuthold, Mazak's director of inside sales.

Everyone is familiar with the use of "automation" to describe material handling enhancements, such as load/unload tables and material storage towers. But Leuthold also stressed "automated" functions on laser cutting machines. He said these are often overlooked, but not having them can cost fabricators in the long run.

As an example, he focused on the common practice of running a laser cutting machine with one lens and nozzle combination, even if the machine is cutting different materials and thicknesses. The perception that uptime is most important is false because the machine is not operating as efficiently as possible. The cutting process is not "optimized," Leuthold said, and as a result, the fabricator is wasting gas, not cutting as fast, and likely delivering parts with poor edge quality.

Ignoring these ideal cutting combinations--where the laser focal length and nozzle selection are correctly matched to the metal being cut—is not intentional in most cases. In the end, the operator may not know better, or the pressure to limit downtime may force the operator to take some shortcuts.

In one example, Mazak's service team took a look at the practices of a fabricator engaged in laser cutting a mix of mild steel, stainless steel, and aluminum parts. They found that the less-than-optimal approach to monitoring lens and nozzle selection during cutting added an extra $7 more per hour to run the lasers. Over a year's time, that resulted in an extra $8,000 per month in gas cost.

Automated functions in the company's most advanced flexible manufacturing systems provide the means to stay on top of optimized cutting parameters, not leaving it to the operator's responsibility. Automatic torch changers ensure the correct focal length is used for the cutting job, and the correct nozzle is matched to the job as well. Sensors always provide the correct focal point measurement before cutting ensues, and automatic nozzle grinding keeps the splatter off the lens, ensuring sensors can deliver that accurate focal length distance.

Other technology advancements help as well. Sensors in the cutting head can sense when a problem—such as self-burning, which occurs when fabricators push the laser to cut mild steel—is imminent and slow down the cutting process to avoid much larger quality problems. Sensors also can be used to streamline piercing routines because they can detect when the pierce is complete; such technology has helped to reduce piercing times by several seconds when compared to older laser cutting technology.

Such automated functions all add up to increased feed rates, decreased gas usage, and decreased labor costs. They also allow fabricating companies to control their costs—postponing the need for adding direct labor and the complexities that come with that.