Author: Derek Kern

Laser engraving can take some getting used to. Even seasoned operators will find themselves confronted with the occasional head-scratcher during a laser engraving project. Below, I’ve outlined a handful of laser engraving tips and techniques to help you avoid costly mistakes.

What are some of the common mistakes laser owners and operators make that end up costing them in the long-run? Here are four laser engraving mistakes to avoid.

WRONG AIR PRESSURE

Setting the proper optic air pressure when cutting metal is a very important step, and you will notice the negative effects of incorrect air pressure almost instantly.

When it comes to engraving, air pressure commonly gets overlooked as most materials are much more forgiving, and the air pressure setting is not critical. However, there are certain engraving and etching applications where setting the air pressure correctly is key.

One of these applications is plastic etching—such as an acrylic sheet. Using a higher optic pressure through a small nozzle concentrates the air flow onto the area being processed and can leave a hazy ghosting or shadowing effect around the etched area. By simply decreasing the air pressure you might see a decrease in this effect immediately. Don’t turn off the air completely, as you do need some positive pressure to keep smoke from entering the beam delivery.

Another tip to go along with this is using a wider nozzle opening. Kern offers a wide nozzle that can be added to any S-FOCUS assembly.

SKIPPING THE TEST RUN

Before diving into a new project, it pays to run a little test cut on an excess piece of material, even when you’re relying on presets. The fact of the matter is, you never truly know what the final result will be until you see it. Material variation is a common problem especially in wood and stone.

One tip here is using a neat feature in our KCAM laser software. The “Position in File” feature allows you to move to any engraving line in your project. If there is a more critical area of your engraving with lots of detail, you can simply type in that line and the laser will start at that point. KCAM makes it easy and highlights the line you type in so you can get to the line you are looking for easily.

Notice the red and cyan line across the engraving file below. Generally, an inch or two of engraving will give you a good idea if your settings are correct.

TREATING ALL MATERIALS THE SAME

Laser engraving leather is going to be different from laser engraving glass. And the same thing goes for engraving acrylic or wood. These materials are all different, and those differences impact how they respond to laser engraving.

Taking the same approach to laser engraving regardless of material types is a recipe for disaster. There is no one-size-fits-all to laser engraving, because the variables—and possibilities—are endless.

The KCAM software accompanying your laser system includes the ability to save your settings in a directory for future use. This works great for customers that process the same materials on a regular interval. Simply load in the settings file and you are back to the same great settings you were using a month ago on the same material. This helps to maintain consistent engraving from job to job, and it helps reduce startup time for each project.

Over time, your settings directory will become one of the most important parts of your system!

FORGETTING TO CLEAN YOUR MACHINE

Are you noticing your laser engraver’s performance is slower than it used to be? It might be time to give your machine a thorough cleaning, with special attention to the optics. Like any piece of equipment or machinery, laser engraving machines require routine maintenance.

Depending on the materials you are engraving, dust and debris buildup may be a frequent problem. It is important to make sure your vacuum blower system is running efficiently. Ensure there is not build up in your vacuum hose lines and smoke/dust is quickly being picked up by the vacuum ports. As always, check your operator’s manual for tips on cleaning your machine and other maintenance specifications, especially if you’re noticing a sharp decline in processing speed.

One common mistake I see is when customers are using a known good setting but for some reason they are not getting the results they did previously. Most users instinctively increase the laser power to get back to the proper setting. However, most times that is the last thing you want to do. The best solution is to determine what is causing the drop in power. It could be a dirty optic that just needs a good cleaning. If you ignore these warning signs, the increase in power will only heat up the optic more and eventually it will crack.

For customized laser engraving tips and techniques, you can always connect with the team at Kern Laser Systems to discuss your approach to engraving. Oftentimes, it comes down to understanding your material, your laser system and how the two react to each other. Luckily, getting the hang of laser engraving is relatively quick and easy, especially when you have the support you need. 

At Kern Laser Systems, we’ve cracked the code on combining low wattage CO2 lasers and metal cutting applications. Our customers have been doing it for years! Request a demo to see it for yourself or keep reading to learn more.

Here at Kern Laser Systems, we’ve developed metal cutting technology that enables CO2 lasers of 100 to 650 watts to quickly and efficiently cut metal. This technology makes thinner gauge metal material, like stainless steel, aluminum and brass, processable via CO2 lasers.

METAL CUTTING TECHNOLOGY

Our metal cutting option was developed internally by the team at Kern Laser Systems. It allows our customers to save time, lower operating costs and laser process sheet metal with intricate designs.

Watch this video to learn more about this innovative laser technology:

As you saw in the video, Kern’s metal cutting technology allows for laser processing of stainless steel, mild steel, aluminum and other light gauge metals without the high operational costs of a large, multi-kilowatt laser.

In fact, the sheet metal applications that fall within Kern’s metal cutting capabilities have been known to shock customers.

Here’s a cut edge comparison between oxygen and nitrogen assist gasses. These gasses are injected through the metal cutting nozzle, resulting in a dross-free cut edge on cut metal.

In terms of cutting capabilities, a 500W laser outfitted with the laser cutting option can cut:

• Mild steel up to 4.8mm thick
• Stainless steel up to 3mm thick (with oxygen assist)
• Stainless steel up to 2mm thick (with nitrogen assist)
• Aluminum up to 1.5mm thick

The metal cutting option is compatible with four out of the five CO2 lasers in the Kern lineup. The Kern lasers compatible with the metal cutting option are:

• OptiFlex
• LaserCELL
• OptiDual
• MICRO

Once properly outfitted, these CO2 lasers will etch metal, providing stunning, intricate and consistent results.

The products created with our metal cutting options are endless. From control panels to interior design, our productive and accurate metal cutting technology is a perfect fit for your business needs.5

The COVID-19 crisis has placed intense pressure on companies as we strive to maintain (and potentially future-proof) bottom-line revenue amidst possible shutdowns, corporate mandates, and operational changes. As the pandemic is teaching us, unique challenges require unique solutions as well as pivoting where required. At Kern Lasers, we’re always impressed with the work our customers do and appreciate where our efforts help them achieve theirs. Now, more than ever, we’re in awe and proud of the work our customers are conducting to combat the effects of COVID-19 and its far-reaching implications within industries and the economy alike.

Here are some of those stories of impact and versatility.

WOODCHUCK USA

Ben VandenWymelenberg is the founder and CEO of WOODCHUCK USA, a Minneapolis, MN-based custom wood production company specializing in truly unique gifts. As Minnesota entered the shelter in place mandate from Governor Walz’s Stay Home order, Ben entered his company into a new production territory.

Originally, WOODCHUCK USA shifted half of its production to face shields for medical staff members and personnel, developing a prototype within 24 hours of the decision. As word spread and obvious need grew, Ben and team shifted 100 percent of its production to that of face shields, cranking out 45,000 a day at first, and ramping up to 105,000 units per day now. Ben said their team recognized the “extra, extra high demand” for PPE across the U.S. and made the unanimous choice to support the cause. He explained that the face shields are compliant with N95 masks and are produced at John Hopkins’ standards. The face shields essentially elongate the lifespan of N95 masks worn by medical professionals on the frontlines of this crisis.

On the company website, Ben writes, “As an entrepreneur, you get used to the daily intensity of ever-changing situations and opportunities to grow. The opportunity to go against the beaten path, venture out, experience something new, and forge a new road. Over the past few weeks, we have all experienced an exponential amount of change. A change in the global markets, a change in our national procedure and benefits, a change in our state policy, likely a change in our employment, and a change in our homes and family life. Myself and my entire team here at WOODCHUCK USA are standing by and ready to help in whatever way possible.”

Order Face Shields from WOODCHUCK USA

Watch Ben’s Video via LinkedIn

Kudos, Ben and the entire team at WOODCHUCK USA. As part of your mission statement reads, your passion is to be a daily reminder of our planet’s vulnerability … it’s not about you, it’s about your planet and how you can make a difference now.

I’d say you’re doing just that.

LASER CUTTING, INC.

LCI is a full-service sign and point-of-purchase display house located in Milwaukee, WI.  For nearly 30 years, LCI has served the industry to design and manufacture signs and displays, while also offering laser cutting and laser engraving services with secondary operations. Now, for perhaps the first time ever, Laser Cutting, INC. has turned its capabilities to that of the growing PPE shortage in a time of global pandemic.

John McMillan is the sales manager at LCI and shared, “We have 10 lasers for short lead times and make protective barriers, face masks, and other custom parts. Our lasers can cut most non-metal substrates, and we are making essential parts for fighting the Coronavirus.”

Inquire About LCI for PPE Needs

Connect with John on LinkedIn

We appreciate your service, John and team, and applaud your efforts!

FAULKNER PLASTICS

Faulkner Plastics is a family-owned and operated plastic distribution and fabrication company celebrating its 50th year in business. Based in Hialeah, FL near Miami, Faulkner Plastic is a source for all types of plastic custom fabrications for retail, wholesale, and export. Though Faulkner has decades of experience, the company hadn’t produced any medical equipment, but the coronavirus changed all that.

Responding to local fire and rescue and first responders in Hialeah facing a shortage of PPE and safety equipment, Faulkner Plastics quickly flipped production to plastic face masks. Joseph McCabe, VP of Faulkner said, “we’re operating 24 hours a day now to make these face masks.”

Mask orders came in rapidly and the first batches were in the hands of first responders and emergency personnel by March 26th. In addition to the City of Hialeah, Faulkner also collaborated with Lawrence Franchetti, CEO of One Beat Medical in Miramar, FL, a business that distributes medical supplies. After learning about the new equipment Faulkner Plastics is creating, he reached out to the company to help get the equipment in the right hands. He told 7 News Miami, “We are able to work with them to protect our first responders out there.”

Because Faulkner Plastics has been successful in making these face masks during the upheaval of normal business, they’re currently looking at different organizations across South Florida to determine who they can help during this pandemic.

Watch News Story via 7 News Miami

Way to go, Joseph and Faulkner Plastics crew. Florida is lucky to have you.

CLEAR IMAGE, INC.

Based in Glendale, AZ, Clear Image, Inc. has been manufacturing lucite embedments for over 30 years. As one of only a few embedments producing manufacturers in the world, Clear Image, Inc. offers in-house casting, printing, silk screening, lasering, fabrication, design, artwork, and now, USA Splash Guard a new line of business dedicated to the COVID-19 crisis.

When the shortage of PPE products started being reported by the media, the company’s first thought was, how could we help and how do we keep our staff working through this? The answer became obvious: face shields.

They purchased the necessary materials, and found an inexpensive conveyor that was refitted and motorized to accelerate the bagging, boxing, and shipping process. In a matter of days Clear Image, Inc.’s went full throttle into manufacturing face shields. The team at Clear Image, Inc. is now in the process of bringing on a second shift to help fill the shortage of PPE’s.

“I’m so proud of the way our staff has responded to this change in direction” said Greg Smith, owner of Clear Image, Inc. “My creative team is working on the assembly line right alongside our shop and management team. This is a true case of American ingenuity and USA manufacturing at it’s finest. The worst of times does bring out the best of people. I wish everyone in the country could get a glimpse of our day to day operations… it would give them hope.”

Keep up the good work.

EXCEL PLASTICS

Excel Plastics has three locations — two in Minneapolis and one in Fergus Falls, MN. Currently undergoing marketing initiatives including a rebrand as Excel the company also shifted its production from typical custom point of purchase (POP) for visual merchandising in retail settings to PPE capabilities. The company had a team meeting to determine how they could keep their business running as essential to ensure employee welfare while also serving a need for the community. That led Excel to produce plastic face shields from a prototype, resulting in the first batch of 4,ooo units created for Lake Region Healthcare in Fergus Falls.

Craig Koefod is Excel’s COO and told Otter Tail Lakes Country, “As a local family-owned business, we pride ourselves not only on making great products but also in the way we care for our employees and our community. We are privileged to help in any way we can,” Koefod said.

Because of Excel’s specialty in plastic, the company is also considering other products that can aid in the safety and protection of individuals during the pandemic, including sneeze guards or other plastic installations to be used in public settings, like grocery stores and other essential businesses.

Watch Excel Plastics Story via Otter Tail Lakes Country

Order Face Shields from Excel

Craig and everyone across the Excel brand, thank you for serving your communities so well.

The k-vision package is a fully integrated hardware and software solution that allows for accurate cutting of printed materials. This process starts with a nozzle mounted camera which automatically measures the dimensions between registration marks on printed materials. The following are a few tips to consider when creating registration marks.

SHAPE

The shape of a registration mark is a critical factor. The K-VISION camera can recognize a variety of shapes. However, the two most popular and accurate shapes are circles and crosses. Circles and crosses are concentric and work great as they share center points. All registration marks used in a file should be identical in shape, rotation and appearance.

CONTRAST

Registration marks with good contrast between the mark and background are ideal. The most common configuration is a black solid fill dot on a white background. Image 1 displays a very good contrast, which will result in a high confidence mark recognition. Image 2 displays a poor choice of background use. Glossy sheets and low contrast sheets may require additional fine tuning for dot recognition.

SIZE

The K-VISION camera assembly is mounted directly to the lens assembly. The camera has a field of view of about 1.5” x 1.5”. For accurate recognition, marks should be sized from .080” – .250” in diameter.

NUMBER

For every part that is laser cut a minimum of three registration marks is required. In general, the more registration marks placed around each part, the more accurate the final cutting result will be. When considering large parts, we suggest a registration mark every 6 – 12 inches around the part.

LOCATION

The location of the registration marks is critical to achieve accurate cutting performance. Registration marks should be located on the outside corner extents of each individually cut part.

For more information on Kern’s K-Vision Camera System, please contact our friendly sales team.

Paper Honeycomb

This product is an alternative solution to using standoffs, acrylic slats or aluminum honeycomb. Paper absorbs the laser’s energy and does not result in flashbacks or tick marks on the backside of the materiel being processed. Kern’s paper honeycomb features a flame retardant coating which reduces the chance of fires and prolongs the honeycombs life. This product is best used for applications with cut rates of .5″/sec or greater. Paper honeycomb is considered a consumable and will have to be replaced from time to time.  The following video shows a Kern Laser System processing acrylic on the paper bed structure.

Paper inserts of 52″ x 50″ are now available on the LaserLocker.com website. Please check out our other cutting bed options like the aluminum honeycomb, acrylic slat bed and various spacer options.

About Kern Lasers

Kern Laser Systems was founded in 1982 by Gerald Kern, with the main objective to design and manufacture top-quality industrial laser cutting and laser engraving machines to meet demanding production schedules. The company headquarters are located in the beautiful lakes country of Minnesota. The facility consists of a modern 70,000 sq. ft. building with 50 full-time employees.

Kern Laser Systems started by supplying motion systems for the existing computerized rotary engraving machines. As the sealed CO2 lasers became commercially available, Kern incorporated its motion package with the laser, developing a complete turnkey laser cutting and engraving solution. Kern’s vision has always been to manufacture laser systems that will fit the customer’s needs, at an affordable price, with the versatility to suit a variety of industries.

Today, Kern Laser Systems is proudly owned and operated by the first and second generations of the Kern family. Our goal moving forward is to constantly improve our products, improve processing times and continue to offer our customers the best customer service in the laser industry.

Reducing Back Splatter / Reflection

Many of you have likely experienced the disheartening feeling of opening up a lens assembly and finding pits or a complete rupture of your focusing lens. These special optics can be an expensive maintenance item, especially when processing materials that tend to generate high levels of back splatter.

SPLATTER 101

Splatter refers to small particles of metal that are released when laser cutting metal. Most of these small particles fall through the cut kerf and into the table chamber. However, small amounts of splatter can still find their way into the beam path. Eliminating splatter is not possible, but the following tips will help to reduce the amount of splatter or eliminate its ability to enter the beam path.

PROPER PIERCE

Customers are always looking to optimize their settings to achieve the fastest cut or best quality edge. They tend to ignore optimizing for proper pierce settings. However, the vast majority of splatter is generated during the piercing process. In general, the thicker the metal, the more splatter generated, the more likely the lens is affected. The best practice is to pierce with the smallest nozzle hole possible to reduce the amount of splatter generated. When piercing reflective metals such as aluminum, brass and copper a high power and moderate assist gas pressure, results in a nice small pierce point. When cutting thick mild steel, the ideal pierce is generally achieved with a lower power, lower assist pressure, along with a longer pierce dwell. For example, when processing 4.5mm mild steel on our 400W CO2 laser, we generally use a 3 second pierce, 35% power and 40 PSI oxygen.

INVEST IN A COVER LENS

A cover lens is a protective barrier that is specially designed to fit between the nozzle and focusing lens. Kern refers to their covers lens as the K-Lens for CO2 laser systems and F-Lens for the FiberCELL. These sacrificial lenses are considered a consumable. However, they are priced economically on the LaserLocker.com website.

Starting in 2017, all of Kern’s V-FOCUS metal cutting optic assemblies include a K-Lens. The K-Lens are accessed by unscrewing the lens holder from the ceramic isolator. This allow for easy replacement without having to remove the focusing lens. The V-FOCUS metal cutting assemblies are compatible with and laser system that uses the 1” round optic tube. We suggest customers prior to 2017 invest in a new V-FOCUS assembly, especially if you find yourself replacing focusing lenses often.

The FiberCELL machines are equipped with a LaserMech FiberMini beam delivery. This delivery has a very convenient cover lens drawer that can be accessed without removing any components. This allows operators to check the F-Lens often and replace as needed.

NOZZLE SELECTION

A variety of nozzles are available for Kern’s laser systems. The standard nozzle on our CO2 metal cutting assemblies have a 1.5mm diameter opening. If you find yourself replacing your optics more frequent that you like, try switching to a 1mm nozzle. The beam alignment through this smaller nozzle becomes more critical and will need to be re-calibrated. However, the smaller opening drastically reduces that amount of splatter reaching the optic.

The FiberCELL system is equipped standard with a “double-nozzle”. Double nozzles are essentially a nozzle within a nozzle. As the cutting gas enters the first nozzle, cross airflow is created. This cross flow creates a barrier, which greatly reduces the return of splatter, prolonging optic life.

GAP DISTANCE

This aspect is pretty basic. A larger gap between the nozzle and material being cut reduces the amount of splatter that successfully makes its way back into the nozzle. A general rule of thumb in the laser industry is to set your gap at the same thickness as the material being cut. The theory being the thicker the material, the more splatter, the larger the gap you need. I have found this tip to drastically reduce pitting on the cover lens especially when piercing thicker materials that tend to splatter.

The FiberCELL FiberMini AF (Auto Focus) is capable of adjusting the focus point of the laser beam automatically in the KCAM software. This is a super powerful feature to reduce back platter during pierce. To setup this properly, set the gap distance to a very large amount like 7mm. Then drop your focus down in the KCAM software so that the pierce point is at the top of the metal. This setup results in a quick pierce through the metal and a drastic reduction of splatter as the nozzle is far away from the metal being processed.

The CO2 V-Focus assembly also has a variable knob which allows adjustment of the focus point when changing gap distances. On older CO2 machines with fixed optic assemblies the lens would need to be physically adjusted when a gap change is made. I recommend our CO2 customers invests in the new V-FOCUS lens assembly, it will save you a lot of time and reduce maintenance costs.

NON-METALS

When piercing plastic, wood, foam and other non-metals, splatter is not generally an issue. However, smoke and residue are created during the piercing and cutting process. The vacuum system will remove a majority of the smoke and residue, although some lingering traces may collect on the focusing optics. To help combat smoke and residue from getting into the nozzle, a knife air should be used. The knife air is installed on Kern’s laser shroud and injects compressed air perpendicular to the cut, pushing the smoke and residue away from the nozzle opening.

FINAL THOUGHTS

Again, the vast majority of splatter is generated during the piercing process. Operators should start by optimizing their pierce settings/gap and installing a cover lens. These two items alone will save you a great deal of time and money!