Conducting the laser

The whole orchestra is greater than the sum of its parts

The FABRICATOR March 2013
March 1, 2013
By: Tim Heston

Elizabeth Kautzmann, chairman of FMA’s Industrial Laser Council, keeps one eye on laser technology and another eye on a part’s overall processing time.

Conducting the laser -

Elizabeth Kautzmann

Elizabeth Kautzmann breathes laser technology. She may talk of Faulkner, Plutarch, Einstein, and laser pioneer Theodore Maiman in the same breath. To her, the light emitting from the processing head is not just a certain beam mode or power level. It represents human potential.

She was hooked at age 9, when her father, a physics professor, brought home a helium-neon laser. Seeing that red beam for the first time left a lasting impression. During her senior year in high school she spent her evenings at Cincinnati Technical College, and continued her studies with a triple major: chemistry/metallurgy, electronic engineering, and laser/electro-optics technology. Her background includes stints at Armco Research and the Edison Welding Institute.

Today she is laser program manager for FANUC Factory Automation America (FANUC FA America), supporting customers in the Americas, and the current chairman of the Industrial Laser Council at the Fabricators & Manufacturers Association Intl. With such a CV, it’s no wonder colleagues call her Laser Liz.

Kautzmann’s perspective on lasers encompasses much more than one would expect. She grew up in a research environment, studying the minutiae of laser beam development. Yet she always weaves the minutiae into a broader view. To her, a single-mode laser with a near-Gaussian beam is a beautiful thing not in and of itself, but because of the possibilities it reveals.

This isn’t pie-in-the-sky talk, either. When The FABRICATOR sat down with Kautzmann earlier this year, she didn’t focus on the laser technology itself, about how on the horizon multikilowatt systems may fit in a briefcase. Instead, she focused on the control of that laser technology.

As Laser Liz sees it, the laser already can perform a jaw-dropping variety of manufacturing processes: cutting, welding, surface finishing, heat treating, peening, and even some mild forming. The bricks are there; during the coming decades, the control and software will be the mortar, essential to take it to a new level.

Kautzmann is a laser scientist who keeps one eye on the technology, another eye on overall processing time. A central tenet of lean manufacturing and related improvement methods entails looking at the whole picture, including a part’s processing time and idle time. It may take five days for a part to make it through cutting, bending, welding, finishing, and assembly, but actual processing time may be only several hours. For most of the time, the part sits between processes.

She knows that blazingly fast cutting speeds certainly make laser processing more efficient than ever, but that efficiency doesn’t count for much unless more products ship in less time.

The FABRICATOR: How has the laser fit with the concepts of lean manufacturing over the past decades?

Kautzmann: The conventional understanding has assumed that if the laser is making sparks and making parts, it therefore is making money. Conversely, if the laser is idle, it’s losing money. This view may be especially true for new equipment owners. However, when you look behind the machine and see stacks of laser parts and skeletons on skids, these mounds of parts may look impressive, and invoke confidence that the laser is making money—but is it smart money?

During the past decades, we’ve seen laser cutting speeds reach incredible proportions. It’s no longer practical to batch-and-queue, to manufacture mounds and mounds of parts. The laser is a soft cutting tool and, as such, can cut nearly any profile imaginable into a sheet. Software has done an incredible job at dynamically nesting and influencing part sequencing, so that part kits flow smoothly to processes downstream.

It’s about calculating true part cost. Traditionally, software has estimated the cutting cost by how long it took to actually perform the cutting. But this really doesn’t capture what it actually costs the organization to produce it.

The FABRICATOR: Explain what you mean by “true costs.”

Kautzmann: Let’s take the most straightforward scenario. Say we’re a low-product-mix product line manufacturer that nests five identical parts on a sheet, and the laser machine runs 100 sheets. Even if you cut these components in an unattended, lights-out situation, you still have stacks of cut parts to deal with when you come to work the next morning. Depending on the automation you have, those parts may need to be removed from their skeleton and sorted. And the parts at the bottom of the stack may sit for a long time, waiting to be handled. In other words, the parts at the bottom of the stack take longer to flow downstream and, hence, cost more than the parts at the top of the stack.

Even in this case, in which every part is identical, the first part on the initially cut sheet—now at the bottom of the pile—is delayed for a longer time than the last part the laser cut, which now sits on top of the pile. But I guarantee that the sales department quoted identical prices for both pieces. The cost to the shop is not the same, and this obscures the true margin.

The only way to resolve this issue is with intelligent shop management. It requires the CNC to report real-time data. This can allow third-party software to calculate and predict best-practice adjustments to maximize margins for every piece in the order. An ERP system then can update the pricing structure for the next time the job comes in the door.

A system is only as strong as its weakest link—and in many cases, the laser is not the weakest link. The ultimate factory solution is constant part flow from raw material to shipment.

The FABRICATOR: The laser can be a phenomenal multitasker, processing myriad jobs on one sheet. But is there a balance? How should sorting time and downstream part flow fit into the equation?

Kautzmann: Certainly, shops need to put constraints on their process, and this is more important now than ever, because the laser is now capable of cutting at the greatest speeds. You need to look at the entire shop floor. The symphony has a conductor for a reason, and you can’t have one section of the orchestra run away and create parts that aren’t needed immediately.

Instead, you need to begin with the end in mind. Where are these parts going to be staged? If these parts don’t make it to a downstream process in time, do you suspend the current job on the laser to start producing parts for other jobs? It’s very common for a laser to create a lot of parts quickly, but how it influences bottlenecks down the road needs to be managed. And this isn’t always put into the part cost estimates we use.

In fact, downstream processes like bending and welding experience far more variability. A press brake technician may position a part incorrectly and form a part backwards—not ideal, but it happens. In this case, the laser can respond, change gears to produce the unexpected job, and then resume its previous program quickly.

The laser has become one of the most flexible and predictable machine tools on the floor. It has the ability to respond quickly to interruptions, and that is much more powerful from an efficiency standpoint than a system that is always cutting.

In this case, constant part flow is the ultimate end goal. This is where line automation can be beneficial. Line automation is relatively new for laser fabrication. But if we look at other markets entrenched in automation—automotive, for example—we see successful examples of how fabrication must also follow suit to maximize efficiency.

The FABRICATOR: And what role do software and control technologies play in all this?

Kautzmann: The control can analyze three cases —“Where I’m supposed to be, where I really am, and where I’m going”—all at the same time. Today’s advanced CNCs enhance laser processing by synchronizing an incredible volume of data, commands, gates, look-ahead, and live feedback from processes downstream, which all are considered in their significance as the system is processing.

Such feedback allows you to focus on flow, not laser cutting speed for speed’s sake. Again, laser cutting more parts in less time doesn’t necessarily equal higher effectiveness of the overall shop.

This also entails looking at the time and effort between processes. Consider parts marking. Marking parts inside the laser’s work envelope slows the cycle time, but it certainly eases part flow and tracking downstream.

Consider also the act of offloading parts from the cutting process. A laser may spend time cutting the skeleton. This stress-relieves the web between parts, so you avoid bowing the metal, making the process more predictable. Here, the CNC dynamically controls cutting so the machine can handle scrap with as much intelligence as it handles parts. It can make those skeletal cuts at the maximum feed rate possible while making a full-penetration cut. The CNC then instructs the laser to modulate to different parameters to cut clean edges for parts. This all reduces the amount of direct labor required to handle scrap.

If interior and exterior scrap isn’t destroyed or otherwise managed, you can threaten the consistency of any sorting device to effectively remove the part from the nest. For instance, if one area of the nest does not use microtabs, the parts can no longer be assumed to keep their original position. Intelligence must be tied into the sorting, either with vision systems or other means.

This intelligence also includes updates to plantwide systems. Manufacturing execution systems have become advanced enough to adjust and keep the schedule dynamic, based on what’s really happening on the floor. Communication between the machine, the execution software, and the system monitors can keep downtime and hot-job interruptions to a minimum. The quicker you can adjust, the greater your success. Ultimately, this will differentiate an elite manufacturer from the masses.

No shop floor can be perfectly efficient. Instead, we need to be looking at how quickly a part progresses through a shop. Put another way, we don’t need perfection, just progress.

The FABRICATOR: What do you think our children will see on the fabrication shop floor?

Kautzmann: As we’ve discussed, the laser is a flexible, dynamic tool that can stop and change direction quickly to ensure efficient part flow downstream, minimizing the hours or even days of queue times downstream.

Our children, though, may see a shop floor that takes this one step further. Today material movement and queue times make up the lion’s share of manufacturing time. So, ultimately, the best practice would be to have material move the least amount with the most number of processes happening to it.

The shop of the future may have parts that are designed in ways that we probably can’t see yet, because we just haven’t implemented the practices that take full advantage of the laser’s versatility. Such combining of processes is happening right now in laboratories.

The FABRICATOR: So are you talking about a machine that can do it all—cutting, welding, part marking, heat treating, peening, and maybe even forming? Like a Swiss army knife of metal fabrication?

Kautzmann: Well, yes and no. It may not be cost-effective to put all those capabilities into one system. But one thing is for sure, I know I will want one, because at the heart of it, I know there’s going to be a laser with advanced CNC technology.

Tim Heston

Tim Heston

Senior Editor
FMA Communications Inc.
2135 Point Blvd
Elgin, IL 60123
Phone: 815-381-1314

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The FABRICATOR is North America's leading magazine for the metal forming and fabricating industry. The magazine delivers the news, technical articles, and case histories that enable fabricators to do their jobs more efficiently. The FABRICATOR has served the industry since 1971.

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