The laser (CO2 and fiber) cutting machine has become the ultimate cutting tool for sheet metal in recent years. It’s also one of the most rapidly evolving technologies in metal fabrication and not so long ago you’d be hard pressed to find a fiber or disk cutting laser at a custom fabrication shop. Today they’re popping up everywhere. Some figures bandied about say that 28 machines were imported into South Africa just from China, last year.
Guenter Schmitz of TRM Supplies, a company that has specialised in the sourcing, importing, and installation of a wide range of new sheet metal machines, as well as offering service, support and repairs of the equipment, believes that the manufacturing industry in South Africa needs to be educated about the do’s and don’ts of purchasing a laser cutting machine.
“For most manufacturers, buying an industrial laser cutting machine is a major investment. It’s not just the initial price you pay, but the fact that the purchase will have a great impact on the entire manufacturing process. If the wrong equipment is chosen, you have to live with the decision for quite a long time. It is not unusual to see manufacturers keep a laser for seven to 10 years, before upgrading,” said Schmitz.
“Do you know the best way to go about purchasing a laser cutting machine? Even if you currently own one, how long ago did you buy it and what has changed since then?” continued Schmitz.
“Production managers are always on the line for costs. Whenever the economy takes a dip, the microscope comes out for a closer look at how an operation can be more efficient. For a custom fabrication shop, one way is to bring the laser cutting work that they were previously outsourcing – a big decision – in-house. What they do not realise is that along with this comes a multitude of learning curves and problems, mainly because of the lack of experience and know-how of the process.”
“But there will come that time when you have to ask yourself if it is time for the company to bring laser cutting in-house. This has to be considered even if the business relationship with the subcontractor is great. If the decision is made to bring laser cutting in-house, you may be put in a position where you need to justify why the investment needs to be made. The costs associated with subcontracting out the laser cutting are just the starting point for the justification. How much more productive will the manufacturing process be with in-house laser cutting? How does this affect lead times? From an expense standpoint, not only do you have the cost of the laser cutting machine, you have labour and consumable costs.”
“This scenario doesn’t involve a lot of risk and can work if you have some flexibility with lead times.”
“Lasers have become the true workhorses of metal fabrication, and they have never been more productive. They cut nests at unprecedented speeds, which has made material handling automation even more important. All the high cutting speed in the world may not dramatically affect overall cycle time if a laser sits idle for prolonged periods, waiting for operators to load sheets and unload parts.”
“Similar thinking also applies to edge quality. Edge quality is, of course, subjective. A fabricator will look at a laser-cut component and find that the edge quality is not very good. A welder, on the other hand, may look at the same part and see a smooth, consistent, high-quality edge. Regardless, the application requirements dictate what is considered a quality edge or not. A laser can finish a nest of components in no time flat, but what if those components need to be sent through a secondary operation?”
“To evaluate which machine is best for you, you must first understand your application and define your needs and limitations, all the while accounting for new opportunities and future goals. By doing so, you best match the system capability with your needs, allowing you to take full advantage of the productivity, versatility, and quality benefits that automated laser cutting has to offer.”
“For example, since the game-changing fiber lasers were launched they have made their mark on thin-gauge cutting and speed of cutting. Power sources on fiber machines have progressed rapidly and I believe you can even get a 20kW machine these days. All will be revealed at the forthcoming EuroBlech 2020 exhibition in Hannover, Germany in October 2020.”
“The thickness of the gauge that a fiber laser can cut is increasing but at what cost, both in quality and price? I am sure technology will improve but at the moment you must consider CO2, plasma or waterjet cutting, depending on the gauge thickness that you operate in. Each brings its own unique strengths to the table. Which begs the question: Which process is right for you? Or do you even need to go the laser cutting route? Depending on the component volume, a stamping press, a traditional turret punch press or a high-definition plasma system may deliver the lowest cost per component.”
The pitfalls of buying cheap
“These are normal business decisions and manufacturing practice that I have explained. However, South African manufacturers are notorious for buying cheap when investing in capital equipment. It is a generalisation, but I have been around long enough to give an informed opinion. Other than monetary issues, when manufacturers offer reasons as to why they are looking at purchasing a laser cutting machine, they mention control. Ask yourself these questions to see if you fall into this category:
• How many times have we lost business because of late delivery?
• Have we ever had to reject components because of poor quality?
• How would it help our image if we had our own laser cutting capabilities?”
“Once they have said yes to these three questions and the decision to invest in a laser cutting machine is made, then they go and dig themselves in deeper by buying cheap. As a manufacturer, you have numerous sources from which to purchase a laser cutting machine. There are dealers that specialise in used equipment and original equipment manufacturers that offer state-of-the-art cutting equipment and even refurbished machines that may not have the production prowess of new machines, but can still perform much more efficiently than machines of a similar age with no rework done to them.”
“Ask the supplier questions about service availability. Today’s fiber technology does not require as much maintenance as compared to CO2, but when a machine goes down, you’ll want it back up and running as soon as possible. Find out about parts availability and delivery to fix your machine if there is a breakdown. We are working with technology and things do go wrong. This is not taking the human element into the equation. Again, a laser cutting machine that can’t cut because of a damaged part just doesn’t cut it.”
“Also be aware that laser cutting machines from OEMs that are recognisable in the industry typically have higher resale values.”
Technical quality and backup service
“As the name suggests, CO2 laser uses a gas mixture based on carbon dioxide. The mix of CO2 and other gases, commonly nitrogen and helium, is electrically excited to create the beam. Solid-state lasers come in fiber or disk varieties and are available in the same power ranges as their CO2 counterparts. Like the CO2 variety, the name is descriptive, identifying the laser’s beam origin as a solid, either an extruded glass fiber or a small crystalline disk. Both have a rare-earth element suspended, or doped to use the industry term, in the solid matrix that is excited by diodes to emit light in in wavelengths from 900 to 1 070nm (commonly called 1µm).”
“From a facilities standpoint, solid-state lasers do not require nearly as many resources as their CO2 counterparts. Beyond the simplified beam delivery system, possibly of greater value is the modest floor space requirement. These days, fiber lasers from eight to 10kW require just 20 per cent of the floor space of CO2 lasers of similar power. Add the fiber laser’s electrical efficiency, which is three to five times better than that of CO2 lasers, and the hourly operating costs are much less than those of CO2 technology.”
“As fiber laser technology has rapidly advanced over the last several years, it can be hard to distinguish what is important when considering a high-power fiber laser. There are more things to consider than the highest kilowatt rating or the fastest advertised feed rates. Putting an entire package together for your success involves many areas of evaluation and can be challenging.”
“You have to consider the body and table, as well as the stability of these two fabricated items, the laser source, laser cutting head, air compressor, air cooling dryer and filter, the CNC system and many others. These are the standard items on a fiber laser and can be sourced easily, like many of the fiber laser manufacturers that have emerged in recent years. 15 years ago there were probably less than 20 OEM manufacturers of machines and the industry was dominated by a couple of manufacturers of fiber lasers, amplifiers and modules. The market has opened up and there are now many more manufacturers of these power systems, as well as the cutting systems. The software providers and CNC control manufacturers have exploded.”
“The end result is that virtually anybody with a bit of know-how can manufacture a fiber laser cutting machine. Who knows how many there are now? I estimate that in China there could be over 300.”
“This has led to the market being flooded with cheaper options, relatively speaking, and herein lies the problem. Everyone wants to gain market share and you now have a host of new one-man agents and representatives who have little knowledge about the process, have no back-up service, don’t carry spares and just sell on price. Daily we get calls from companies that have gone with the cheap option and their machine has broken down and now they want us to fix it. Well, their machines are still standing still.”
“Besides the power and cutting systems and the CNC controls, there are a whole host of intricate operating features that make up a laser cutting machine. These include the laser cutting heads, the nozzles, the diode modules, fiber block, digital power supplies and digital control electronics, to name a few. Then there are the safety aspects.”
“Technology in this industry over the last 25 years has seen many changes. It’s not just a case of buying from Alibaba and then plugging in and playing!”
“Big technology implementations are demanding. When investing huge sums of money in fiber laser cutting machines with elaborate material management setups, you expect an advantageous ROI. However, in the new rush to install these super-fast cutting machines, you might be discovering that navigating such an implementation project is more than you expected.”
“Like buying a CNC machine tool or your dream car, you need to be educated and informed about your capital expenditure. Deal with those that have the know-how, experience and services and resources to back them up.”
For further details contact TRM Supplies on TEL: 011 974 7744