When the time comes to invest in a new laser cutting machine, potential customers are presented with cut speed tables – charts that list the maximum cut speed in inches per minute that a
laser can achieve on various material types and thicknesses. While the numbers look impressive on paper, the information can sometimes be a tad misleading.
Like a car’s speedometer, just because a cut speed table lists a maximum speed doesn’t mean that the laser will always be running that fast. Maximum speed is achieved in straightaways, and most fabricators aren’t cutting their sheets into strips of metal. They’re cutting various shapes that have corners and curves that can significantly slow down a machine’s cut speed.
Chip Burnham, CEO and co-founder of Fairmont Machinery, the North American dealer for Eagle Lasers, says that acceleration speeds are a more accurate way to measure the speed of a laser cutter and should be the data on which laser technology investments are based. He adds, however, that acceleration speeds aren’t solely achieved based on the power a machine boasts; they are also dependent on the drive system on which a machine relies.
And Burnham would know. Eagle lasers boast some of the highest power levels available on the market. Dubbed ultra-high power, Eagle laser cutting machines reach power levels up to 30 kW. Potential customers should understand, however, that the company’s linear motors play a big role in the speeds the machines can achieve and maintain.
But Burnham doesn’t want you to take his word for it. His customers are extremely knowledgeable and were willing to speak with Shop Floor Lasers to explain the benefits that come from ultra-high-power laser cutting.
Extreme cutting
Upon its founding in 2000, Shrock Fabrication LLC out of Bird in Hand, Pa., has become a go-to supplier for custom metal fabricating and high-speed laser cutting. As a member of the
National Ornamental & Miscellaneous Metals Association, the company is known for producing custom metal furniture and commissioned art, like the metal sculptures Shrock created for the University of Florida. Its team of skilled craftsmen also produce custom railings, fences, gates, arbors, horse stalls, and whatever other products and designs their customers dream of.
Beyond its custom fabricating services, Shrock is also known for high-volume, high-speed manufacturing and laser cutting. Each year, millions of pounds of metal are cut for customers and other local fabricators that don’t have their own laser cutting equipment in-house.
“We specialize in extreme-volume cutting and bending to customers’ specs,” says Kendall Shrock, the company’s general manager. “We don’t do many small projects. Instead, we’re delivering multiple truckloads of parts to customers’ doorsteps around 18 to 24 hours after orders are placed, on a daily basis. Operating 24 hours, six days a week, having the fastest lasers and the fastest press brakes makes all the difference.”
The high volumes of metal that leave the facility are possible, in part, because of the ultra-high-power lasers in which the company recently invested, including 15-kW and 20-kW Eagle Inspire lasers, the most advanced lasers Eagle has developed to date.
“Ninety-five percent of our work is extreme-volume contract cutting,” he says. “The Eagle laser’s high-speed motion, combined with its high wattage, has a synergic effect on throughput.”
Shrock attributes the machines’ productivity to their ultra-high-power levels, but he cannot dismiss the role of the carbon fiber linear drive systems, which boast 6Gs of acceleration to achieve 14,000 ipm of cutting motion.
“High power in the 15-kW range isn’t typically necessary for 1/4 in. and thinner material,” he says, “but with a motion system that runs two to six times the G forces and speed of many machines, the high wattage becomes useful – when optimized – on sheets as thin as 11 gauge. I would never buy a 20-kW machine with less than 6Gs of motion unless it was for 1/2 in. and thicker plate cutting. The ROI wouldn’t make sense.”
Six Gs require a robust drive system – that amount of force equates to roughly 60 m of motion/sec.2 . For the team at Eagle, that meant developing a propriety drive system. The result was a carbon fiber traverse bridge combined with a polymer concrete composite base, high-power cutting head with linear motors and absolute linear encoders on all axes. Slow-moving hydraulics just wouldn’t suffice.
“In many cases, a 1G or 3G machine never reaches full cut speed on shorter contours whereas a 6G machine allows a much faster ramp-up and much shorter ramp-down,” Shrock explains. “Furthermore, accuracy is better on my 6G machines than any of my other machines, and the cut is surprisingly less shaky and significantly more stable than on our rack and pinion machine. Smooth motion results in a smooth edge and faster cut speed.”
Shrock says that his Eagle lasers’ top speed can be up to 300 percent faster than traditional high-power lasers, which is critical in a high-production environment like his. He stresses, however, that with that type of speed, automated material loading and unloading isn’t just nice to have – it’s critical.
Gradual growth
Glen Zimmerman, owner of Raytec Mfg. in New Holland, Pa., couldn’t agree more about the critical nature of automated material handling. Not only does automation help avoid bottlenecks, but it also enables lights-out operations, which has helped Zimmerman grow the business his grandfather founded nearly 70 years ago.
Raytec originally started out building products for residential housing, such as gutter and roof-related parts, which evolved into the development and design of various agricultural products that required a further expansion into sheet metal fabricating.
“It was crude and rudimentary back in the early days with manual-operated foot sheers and C-unit punching,” Zimmerman explains. “As we increased our machinery capabilities and capacity, we had people asking if we could make this or that, so we did. That’s how the custom metal fabricating division at Raytec came to be.
“Over the years with my father at the helm, the business kept adding capabilities and expanding the customer footprint doing custom sheet metal,” he adds. “We got into CNC punching and CNC bending and then laser cutting, as well.”
For as long as Zimmerman can remember, Raytec had been using laser cutting technology. What started in the 1990s with CO2 progressed to 4-kW fiber lasers, eventually leading to the company being the first in the world to invest in an Eagle 15-kW ultra-high-power laser and then a 20-kW, and now, a 30-kW laser is on order.
“The machine we had before worked well, but we had some new work that was coming our way that required thicker cutting in the 1/4 in. and up range,” Zimmerman says. “We knew that our existing machine was in no way remotely close to being capable of handling that. At various times, we looked into other technologies to upgrade our 4-kW, but everybody was just kind of the same. You get an 8- or 10-kW, and it’s just like what the guys down the road have.”
When Zimmerman first crossed paths with the 15-kW Eagle product line, he thought, “we don’t do 1-in., so why would we even look at that?” After further consideration of the machine’s high power combined with its 6Gs of acceleration, however, the benefits of the Eagle laser seemed to make a lot of sense for Raytec’s needs.
“The original driver for us was the new thicker material work that we were expanding into,” Zimmerman says. “We needed more power at our disposal, but along with that, we needed the versatility of the high-speed machine for our typical thinner sheet applications.”
Zimmerman, however, doesn’t take for granted how helpful the speed and acceleration are for thicker cutting. When the Eagle laser is cutting 1/2-in.-thick material, for example, the laser head can quickly move from one hole to the next, saving the company time that adds up fast. Since investing in the two ultra-high-power lasers, Raytec is cutting 12 times the laser volume it was previously processing.
“When dealing with ultra-high power, it changes the rules and dynamics of cutting thicker materials,” Zimmerman says. “A lot of people have it in their head that if it’s over a certain thickness, they have to cut it with oxygen, but that standard is out the window with Eagle. We can cut faster with nitrogen or mixed gas that results in a very small heat-affected zone at much higher speeds.
“When cutting with older tech, you have to dance around the sheet to avoid heat buildup,” he adds. “The ultra-high power can allow you to cut faster than your heat builds up. That’s dependent on part geometry, of course, but generally you can do that and stay ahead of those heat-affected zones. You can do small holes in thick materials that would have been impossible before with laser cutting.”
Shared success
As owners of some of the fastest cutting equipment on Earth, Zimmerman and Shrock agree on a lot of things, including the ability to cut with nitrogen and mixed gases. In addition to not
worrying about a heat-affected zone, Shrock adds that workhardening also isn’t an issue.
“One of my favorite abilities of the Eagle ultra-high-power lasers is that we can blow a 1/4-in. hole through 3/4-in.- and 1-in.-thick steel plate with nitrogen or a proprietary mix line gas and tap the hole with no secondary drilling or reaming,” he says. “The cut is dimensionally accurate and fast enough to avoid workhardening the metal. This is the beauty of perfected high-wattage laser cutting.”
Being able to use their preferred nesting software is also a point of agreement. Having done years of research on lasers, Shrock can confidently say that Eagle’s controls interface is one of the best in the industry and that because the programming is open architecture, users are able to use their favorite nesting software. Zimmerman adds, however, that it is critical to carefully analyze the software because the chosen nesting capabilities – and the operator’s ability to carry out that work – can make or break a company’s success.
“A customer sent us 3/4-in. material to test; they needed it cut into 1,100 little rectangle pieces with a hole in each piece,” Zimmerman says. “When they came to look at the machine and watch it in operation, they asked how many pieces had been cut because we hadn’t used the entire sheet. When we asked them if they wanted us to cut another 1,100 on the other side of the sheet, they didn’t believe us. It was a remarkable example of what the proper software with the proper machine and the proper technique can do.”
Zimmerman concludes by saying that Raytec “didn’t go out on this quest just to have bragging rights for having the highest power laser.” Instead, the goal was to find ways to utilize technology and grow the business – a true success story, indeed.
