Tipping point for fibre lasers?

Many of the big names, as well as a significant number of small and less well-known names, have added fibre lasers to their cutting armoury. The benefits of fast cutting speeds on thinner materials, low energy consumption, the simplicity of fibre delivery systems, compared to the mirror systems on CO2 machines, and, in theory at least, low maintenance, seem to have driven the sector to a technological tipping point. Fibre lasers could also be disruptive to the established order of the laser market. There were a lot of new entrants on show – with manufacturers coming in from the plasma sector and relative unknowns coming in to attack the new level playing field. Exceptions included Trumpf (01582 725335), which favours its YAG disk lasers over fibre lasers for metal cutting, and LVD (01295 676800) and Mazak (01905 755755), both of which are biding their time and following developments, but are not yet convinced fibre is a mature and field-proven technology. The biggest of the big new entrants to the fibre laser field was Amada (01562 749500), with its widely trailed FOL-F NT series. In a break with its past reliance on third-party laser suppliers, Amada developed its own laser resonator to power the machines. As with all solid-state systems, the beam can be delivered by fibre optic, which means the resonator can be placed well away – so less space is required on the shopfloor. At the same time, the fibre laser is energy-efficient, highly productive and can process difficult materials, such as titanium, copper and brass. With the top-of-the-range 4 kW laser, the Amada machine can process 1 mm stainless at cutting speeds up to 60 m/min. Image: Amada has developed its own laser resonator to support its fibre laser venture Bystronic (0844 848 5850), too, launched a fibre laser system, showing a BySprint 3015 with a 2 kW fibre laser source, aimed at material up to 4 mm. Salvagnini (01989 767032) built upon its coup at EuroBlech 2008, when it showed one of the first fibre laser machines from a big manufacturer, with the launch of its L3 machine. The company has taken the view that it doesn't make sense to simply add a fibre laser to a machine base designed for a CO2 laser. Instead, it has designed the L3 to play to the strengths of the fibre laser. The result is a highly rigid, lightweight and highly dynamic, bridge structure that takes full advantage of the fibre delivery system. This is combined with a patented 'compass' design positioning system for the cutting head that can move it at 5 G over a distance of 170 mm and is superimposed on the axis drives. Image: Not all the new entrants to fibre are low profile. More commonly associated with plasma cutting, Hypertherm (0031 165 596907) has now developed a fibre laser source. As with its plasma units, Hypertherm sells these to cutting system OEMs, rather than users. The 1.5 kW unit is aimed at the 'sweet spot' of what most sheet metal shops require and is sold as a complete package, including CNC, gas management, height control, offline programming software and the laser itself. Hypertherm says that the fibre laser makes machine design much simpler than a CO2 source. There is practically no limit to the size of the cutting area and no complicated mechanisms to ensure constant beam length. This provides an easy route into lasers for makers of plasma machines. It also makes it easy to combine laser and plasma on one machine – with the fibre laser used for thinner material and precise features, and the plasma coming into its own on fast profiling and thicker materials. Several firms at EuroBlech had taken this approach, including Slovakia's Microstep (www.microstep.eu), Italy's Soitaab (Accurate Cutting Services, 01527 527058), which offers fibre laser machines with or without plasma, and the Germany's Messer (0191 250 4610). Under the slogan, 'Why think in black and white?', Messer showed its MultiTherm system – a portal machine that can be fitted with plasma, gas or laser torches – or even two plasma and two laser heads on the same bridge. Again, depending on the thickness, cost, precision and heat input requirements, any process can be used in the same nest, while both laser heads can be used simultaneously. Image: Plasma, gas or laser torches – or even two plasma and two laser heads on the same bridge, is the offer from Messer As a further twist on the combination machine, Eckert Cutting Technology (www.eckert.com) not only showed plasma, water jet, CO2 and fibre laser machines, it also showed a combination water jet/plasma machine. The company says the main benefit comes when a part can take advantage of the strengths of both processes – using the high-quality, low-heat input of the water jet process where the highest accuracy is required, and the fast profiling power of high-definition plasma where it isn't. Tube specialist BLM Adige (01525 402555) has also taken the route of offering both CO2 or laser on its Adige laser cutting machines. On the LT9 combo machine, which can cut either sheet or tube, it offers a 3 kW fibre laser source or a CO2 laser up to 4 kW. A major new market for BLM has been fibre laser processing of copper tube for applications such as heat exchangers. Laser manufacturer Rofin (01327 701100), which showed its first fibre laser at EuroBlech 2008, has now completely switched its solid-state offering to fibre lasers. Rofin 2 kW fibre lasers were being used in laser cutting machines on show from Adira (www.adira.pt), Baykal (Press & Shear, 01827 250000), Ermaksan (www.ermaksan.com) and Soitaab, and on its own stand it showed a new 4 kW source, a compact 1 kW source, designed for integration in machine tools, and its latest remote scanner welding system: a fast, robot mounted beam deflection system for multiple spot welding of complex 3D components. Rofin's Corinna Brettschneider says: "We generally say that fibre laser is best for cutting up to 3 to 4 mm, but a lot depends on the absorbtion as well as the thickness. Its still a big area of discussion. Nobody knows, for example, why the quality of the cut edge on thicker materials is so much better with CO2. There is still a lot of work to be done, but we try to give customers an idea of the things they need to think about." Box item Not just fibre lasers Although the main focus of attention may have been the step change in the laser cutting sector, there was plenty of incremental improvement in punching and forming. An interesting innovation from Trumpf is 'skeleton-free' punching. This uses software to program in common cut lines between parts – saving material and cutting strokes required. Any remaining unused material is chopped up on the table and disposed of down a chute. Safan's latest servo-electronic press-brake is a 300 tonne 4 m machine featuring a new dual-drive system. As with all Safan's E-brakes, the pulley-based drive system ensures a very even distribution of forces so in most cases no crowning control is required. Image: Safan's latest servo-electronic press-brake is a 300 tonne 4 m machine featuring a new dual-drive system The latest Finn-Power Shear Genius 30-tonne punching centre with an integrated right angle shear is now completely servo-electric. The right angle shear has its own servo electric system so its stroke is fully controlled and can be optimised for maximum efficiency. In the field of press brake automation, Amada showed a two-armed robot system that had an almost humanoid look to it. It stands at the press brake picking up sheets, positioning them on the lower beam and then unloading them. The system is teamed with a fully servo-electric press brake and is aimed at high-precision work and exceptionally small workpieces. Image: Amada showed a two-armed robot system that had an almost humanoid look to it First published in Machinery, December 2010