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Clear answers to questions about switching from CO2 to fiber

So you’ve been thinking about investing in a fiber laser, but heard that the pierce times are slower than CO2. Maybe you cut 1-in.-thick mild steel one day and 18-gauge aluminum the next and were told that fiber isn’t nearly as fast as CO2 on heavier gauge materials. Perhaps you’re concerned about poor edge quality, increased nitrogen use and the higher price tag of a fiber laser cutter? Whatever the reasons, whatever the truth behind them, one thing’s for sure: CO2 laser cutting has been a key driver of production floor profitability for decades. Why change?

Because it can adjust beam parameters instantaneously at any point in the cut, the collimation system is the engine behind a fiber laser’s rapid piercing capability and is what allows it to efficiently process thick and thin materials.

Like many trade show attendees and potential customers, if you spoke to Dustin Diehl at the 2018 Fabtech or IMTS shows, you probably heard some very good reasons to make that change. As the laser division product manager for Amada America Inc., Diehl suggests that, while there was once merit to at least some of these claims, there’s simply no reason to take another step down the CO2 laser road.

In case you missed the trade shows, here are some hypothetical questions a customer might have asked as they chatted with Diehl or any of Amada’s other laser cutting experts in person.

Customer: Let’s start with piercing. I cut truckloads of plate steel and can’t live with the long pierce time typical of fiber lasers or the volcano of molten material it causes. What are my options?

Diehl: What if you could pierce 1-in.-thick steel in 1 sec. and have a perfectly clean hole? That’s what Amada’s Ensis technology brings to the table. It allows you to adjust the beam profile at any time, so you can slice through thinner gauge material with a very high spot density, then use a different profile for cutting heavier material or when piercing. Compared to even a few years ago, it’s a huge improvement, most of it due to our collimation design.

Customer: Collimation? What’s that?

Bigger is not always better with fiber lasers, especially if most work is in thinner gauge materials.

Diehl: Collimation is used to adjust the spot size, beam profile and optical depth of field. Simply put, it lets you mimic a CO2 laser when piercing thicker materials, then instantly adjust the profile once you’re through the sheet. Again, you can pierce 1-in.-thick steel in less than 1 sec. and cut that same material at speeds of 40 ipm or more with one of our 9-kW fiber lasers. It’s so fast that you no longer have to worry about heat dissipation as you do with a CO2 laser or an older, less capable fiber laser. And because we mount the collimation unit vertically, up away from workpiece, there are far fewer problems with dust and debris settling on the optics.

Customer: What about edge quality? I’ve heard this can be a problem for fiber lasers when cutting thicker materials.

Diehl: Edge quality is definitely a big deal for many shops, but the mode change capability of the Ensis technology allows you to fine tune the beam to achieve excellent edge quality no matter what you’re cutting.

We’ve also done a lot of work with gas mixing capabilities. It used to be that you’d switch off the nitrogen once you got around 7 gauge or thicker, but we’ve found that, by introducing a small amount of oxygen, you can increase feed rates and improve edge quality in up to 1/2-in.-thick material. Either way, the edge quality from today’s fiber lasers is every bit as good as that of CO2, with significantly greater throughput.

Customer: If a fiber laser pierces faster, cuts faster and produces better edge quality than CO2, why would anyone still buy a CO2 laser cutter?

Diehl: I honestly don’t know. In my opinion, CO2 has been replaced. That’s not to say we won’t sell you a CO2 laser, but they are now considered special orders, available only from Japan. By comparison, all of our fiber lasers and automation for the North American market are made here in the United States.

You might have made a decent argument in favor of CO2 a couple of years ago, but not anymore. In fact, about the only material you can’t cut more efficiently on a fiber laser is wood and plastic, and that’s an iffy proposition on any laser cutter when you consider the fumes and risk of fire. Edge quality, accuracy, cutting speed and now piercing – all of that is either duplicated or greatly enhanced by fiber.

Amada uses three 3-kW modules on its 9-kW fiber laser cutters, which is a cleaner and more efficient approach than that used by competing systems.

Customer: What should I know before buying a fiber laser? And how much power do I need?

Diehl: Contrary to what you might hear, every manufacturer’s fiber laser is different, and beam quality is in large part determined by how the laser and its optics are constructed. For example, some builders reach 9 kW by stacking nine 1-kW modules one on top of the other, but this is a little like stringing a whole bunch of extension cords together – it doesn’t take long before the power at the end of the strand begins to degrade.

Amada uses 3-kW modules, which is a simpler, cleaner and more efficient approach. As for the amount of power you actually need, it depends on what you’re cutting. Bigger is not always better with fiber lasers, especially if most of your work is in thinner materials – if you’re cutting 16-gauge material all day, don’t waste your money on a 9-kW laser because you won’t see any difference in productivity or at least not enough to justify the cost delta. My best advice is to talk to us, talk to others who’ve gone down this road and do your homework. That said, you absolutely won’t be sorry with a fiber laser.

Customer: Is there anything else I should know?

Diehl: There’s definitely more to this than the type of laser and how much power it generates. For example, we offer water-assisted cutting where we introduce a fine mist of water through the nozzle to help keep the plate cool. That’s not the concern it once was because we’re piercing so fast, but it does allow you to nest your parts more closely together. In many cases, our customers are hitting sheet utilization rates of 80 percent or more.

Similarly, we offer an oil shot unit to eliminate any spatter during piercing, although again, that’s not really a problem anymore.

I guess my biggest recommendation is to look hard at automation. With skilled labor increasingly difficult to find, automated material handling makes more sense than ever before. Just be sure you find a system that’s able to keep up. When you’re processing a complete nest every minute or so, you don’t want to buy a system that takes several minutes to load and unload each sheet.

Like I said, just talk to us. Despite a very respectable track record, fiber lasers are still an evolving technology, as is automated material handling. Give us a call or stop by during the next trade show. We’ll be happy to share our experiences with you.

Amada America Inc.

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