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Fiber laser cutting: Reduce grinding and deburring with recessed tabbing

by Robert Farrell, president, Farrell MarCom Services LLC

 

 

 

What would you do with an extra $100,000? From investing in new machinery and technology to compensating employees and making facility improvements, any fabricator could easily find a myriad of ways to put that money to good use. But, for those companies that employ fiber laser cutting, one solution can all but eliminate the time and cost associated with grinding and deburring – while boosting the bottom line.

 

Once considered beyond reach for many metal fabricators, fiber lasers are finding their way onto more and more shop floors. The concentrated laser beam of a fiber laser delivers noticeable edge quality improvement over CO2, waterjet and other metal processing options. And because of their short wavelength, smaller kerf size, beam density and high beam quality, fiber lasers are the best option for high-volume and intricate geometry applications.

 

Overall, tighter cuts mean more efficient nests, and more complete material utilization means reduced scrap rates. With these advantages, a faster return on a fiber laser investment is practically guaranteed, right? Not so fast.

 

Generally speaking, the thicker the material and the faster it’s cut, the poorer the edge quality. Consequently, faster cutting means more secondary grinding and deburring, especially with fiber lasers. For many fiber laser users, the best way to reduce dross is to slow the cutting operation within a range of 200 ipm, negating, for all practical purposes, many of the machine’s speed advantages. Companies employing fiber lasers feel forced to choose between speed and quality.

 

Furthermore, there are a number of added costs associated with material processing, and fiber laser cutting is no exception. From consumables and maintenance to associated software and human resources, the costs involved can sometimes seem overwhelming. When downstream operations can be reduced or eliminated, however, fabricators can take a deep sigh of relief knowing they are offsetting the otherwise required costs of laser cutting.

 

 

 

Tab control   

 

Tabbing, a common method to stabilize and secure parts during the cutting process, helps fabricators ensure a clean cut while minimizing the risk of damaging a part or even the laser cutting head. On the downside, however, tabs and tab remnants often must be manually removed and parts must be ground and deburred in secondary operations.

 

Fortunately, there is a solution to slash or even eliminate the need for grinding and deburring after laser cutting. A new feature in SigmaTek’s SigmaNest software creates recessed tabs to secure parts during the cutting process. This feature delivers clean-cut parts that easily snap out of the nest. No rough edges mean little to no grinding and no (or few) added resources. For the average fabricator, the recessed tabbing feature quickly and measurably impacts part quality and the company’s bottom line.

 

Recessed tabbing is the brainchild of SigmaNest product manager, Kevin Keane. The idea was spawned from an earlier manufacturing software system he saw while visiting a potential customer site.

 

“Different cutting machines have different ways of handling kerf compensation in the CNC controls and those early attempts were unreliable,” Keane says. “Our idea was to develop a way for the users to control the tab width and depth exactly the way they want. In this way, laser cut parts can be efficiently processed without compromising cutting speed or part quality.”

 

For optimum results, it’s recommended that machine operators take a little time to run a test sample and calibrate the tab size to their own application. Ideally, the recessed tab area should feel smooth to the touch. One should feel no sharp edges, bumps, holes or divots.

 

Keane points out that while the feature certainly benefits a range of applications, it’s a perfect solution for fabricators where the laser cutting is followed up by secondary operations. For example, carbon steel parts often end up powder coated or painted and are a perfect fit for recessed tabbing.

 

“Poor edge quality has a direct impact on bending, welding, painting and similar downstream operations,” Keane explains. “Such issues will result in press brake part misalignment, poor welding fixture misalignment and a need for parts to be manually cleaned or scrapped completely. Laser cutting is all about quality and speed, which the recessed tabbing was developed to provide.”

 

Laser Cutting Services Inc. provides its customers with high-precision, tight-tolerance parts that are processed on the company’s four Mazak lasers.

 

 

Put to the test

 

As a specialized job shop providing precision laser cutting of metals, Tualatin, Ore.-based Laser Cutting Services Inc. (LCSI) provides the Pacific Northwest with laser cutting services. Founded in 1995, the company serves a variety of customers representing a variety of industries that require high-precision, tight-tolerance parts.

 

LCSI operates four Mazak lasers (CO2 and fiber) ranging from 2.5 kW to 4 kW. These lasers incorporate auto-focus, non-contact cutting heads along with automated loading and unloading systems that increase productivity by minimizing setup and downtime. Designed and optimized for heavy plate cutting, LCSI routinely uses the machines to cut steel plate up to 1 in. thick, stainless up to 5/8 in. thick and aluminum up to 1/2 in. thick.

 

With two shifts processing hundreds of orders each week, part cleanup time and related costs had become an issue.

 

“In this business, your reputation is everything,” explains Stanley Walker, president of LCSI. “We come to work every day with a mission to provide our customers the industry’s highest quality and fastest turnaround. We rely on new technologies to keep us ahead of the competition and get the results we need to meet customer demands. Time and time again, SigmaNest is at the forefront of such new advancements. When we were approached about a new feature that would slash deburring, we were anxious to put it to the test.”

 

As a long-time SigmaNest user, LCSI was confident that the new recessed tabbing feature would provide improvement. However, the impact it had on part quality and cleanup totally surpassed the company’s expectations. Recessed tabbing resulted in quick de-tabbing and little to no grinding or deburring.

 

“We saw perfect fiber laser cut parts with no rough edges,” Walker says. “Reducing grinding on 4,000-plus parts saves us hours of grinding time and related costs, allowing us to be even more responsive and cost-effective to our growing customer base.”

 

In the case of LCSI, it’s estimated that reducing or eliminating grinding and deburring operations saves the company about $100,000 annually on labor costs. For fabricators facing tight margins and stiff competition, this offers a huge competitive edge.

 

LCSI programming supervisor, David Keniston points out that while it takes a bit longer to post sheets due to added coding, it’s well worth the extra time needed to set up nests with the new features.

 

“With less time spent grinding and deburring parts, we will definitely save time and costs in the cleanup process,” Keniston adds. “And, we’ll be able to run more schedules rather than having to use features like auto-destructing.”

 

The settings dialog allows for precise control of the end result.

 

 

Measurable results

 

With fiber laser cutting, some additional costs are inevitable – even justified: consumables, repairs, software enhancements, and so on. But taking on or reallocating resources for grinding, deburring and related cleanup shouldn’t be one of them.

 

SigmaNest recessed tabbing is shown to not only reduce labor costs, but material costs and consumables associated with grinding and deburring, as well. For organizations with multiple lasers, this can easily translate into savings of hundreds of thousands of dollars.

 

Less grinding also means a cleaner work area with no harmful dust and airborne contaminants harming workers and machines. There are also substantial time, cost and quality paybacks with downstream press brake, welding, painting and cleaning operations.

 

Even lower end fiber lasers represent a hefty investment for most companies. Advanced manufacturing software, such as SigmaNest, therefore, is a key in optimizing cutting performance and delivering a measurable and sustained impact on the bottom line.

 

Laser Cutting Services Inc.

SigmaTek Systems LLC

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