An Austrian manufacturer of motobike chassis components has improved weld seam quality and increased welding productivity with the introduction of a welding system from Fronius, the TPS/i series.
“The TPS/i is not just a development; it represents a quantum leap in all the areas that are important to us”, is how Josef Baier, production manager at WP Performance Systems GmbH, summarises his experiences of working with the latest welding power source from Fronius. The manufacturing specialist bases his opinion not just on the welds he has carried out himself, but also on the results of the widespread use of the devices in frame and exhaust manufacturing. “There is currently no comparable device on the market. That is why we always turn to the TPS/i when we need to satisfy a requirement such as guaranteed penetration, high welding speed or a totally spatter-free weld seam.”
As a result of the benefits the company has realized with the new welding system, WP is now using more than a dozen devices from TPS/i series for frame construction and exhaust manufacturing.
Guaranteed penetration if stick out fluctuates
WP deems reliable penetration to be essential in the manufacture of motorbike frames. Ninety-eight per cent of all the chassis welding is carried out by robots using 25CrMo4 steel. However, robots can’t carry out the remaining 2 per cent, as they are unable to access the relevant locations on the tube intersections. These locations have to be welded by hand. “It is imperative that the required penetration is achieved reliably, even in out-of-position welding or in the case of longer stick outs”, explains Josef Baier. “This is where the penetration stabilizer of the TPS/i comes into its own.” This innovative feature regulates the arc extremely quickly and precisely to ensure that the penetration remains constant whenever the stick out may fluctuate.
The company places another requirement on the quality of the weld seam, even though the TPS/i maintains the penetration at a constant level in the case of very long stick outs, a feature that in itself fulfils to previously unattainable levels one of the most important demands of WP regarding the weld seam. “It is only a few years ago that small amounts ofmspatter on the frame were considered acceptable by our internal quality control team. Today, that is no longer the case”, emphasises the WP production manager. “We now expect even those areas that will later be completely invisible because, for example; they will be covered by the casing to be spatter-free.”
The first spatter-free weld seams
Up to now, spatter has been almost unavoidable when welding manually, even in situations where the most advanced MIG/MAG devices were employed. “Some spatter always seemed to occur, particularly during the start and stop phases”, says Josef Baier. As the seams welded manually by WP during frame construction are very short, the company used to have to invest quite a bit of effort into cleaning them.
A fundamental change took place following the switch to TPS/i. “Now that we carry out the manual welding of the tubular sections of the motorbike frame exclusively with the TPS/i, we can say without any embellishment or exaggeration that the weld seams are spatter-free.”
A significant factor behind this achievement are the new LSC (Low Spatter Control) dip transfer arc characteristics specially developed by Fronius, which, as they exhibit extremely high levels of arc stability, are mainly used by WP to weld the frame.
High gap-bridging ability on thin sheets
LSC Root was specially developed for root passes. Its unique current profile ensures excellent root fusion and gap-bridging ability. The outstanding gap-bridging ability of the TPS/i is especially welcome when it comes to exhausts, as the stainless steel, structural steel or titanium sheets used at WP are usually only a millimetre thick. “With sheets this thin, there is always a danger that the weld seam will drop through”, notes Josef Baier. “Thanks to LSC Root, however, this is not a problem that we face.”
As with frame construction, WP is uncompromising in terms of quality in the production of its exhaust systems. Josef Baier has ensured that the many weld seams that are visible on the exhaust are always welded using a TPS/i device.
As there are many more manually welded seams, not to mention some long ones, in an exhaust system compared with the frame of a motorbike, the welding speed that can be achieved in this application has a marked impact on productivity. This is another area where the TPS/i and LSC show their combined strengths. The new Fronius offering, with its higher root arc pressure and deposition rate compared with the previously available and implemented solutions, is again to the fore in terms of welding speed, as Baier can confirm from practical experience: “With the TPS/i, our welders achieve a welding speed that is about 20 per cent faster than before.”
Faster welding results in higher productivity
WP manufactures all its own exhaust systems, starting with the metal sheets or 6 m long tubes made from stainless steel or structural steel as well as titanium sheets through to the silencers and exhaust manifolds. As a great deal of welding is involved in the production of exhaust systems, productivity since the introduction of TPS/i has increased dramatically, particularly in the manufacture of exhaust pipes. With the production of frame and exhaust systems running at more than 120,000 per year, the acquisition by WP of modern welding systems like these pays for itself within a few months as a result of the practically nonexistent reworking requirement and the higher levels of productivity.
For Josef Baier, the role that this latest innovation from Fronius will have at WP in the immediate future is already apparent: “This power source will enable us to maintain and extend our leading position in welding technology. We have therefore decided to install TPS/i at every workplace where spatter-free weld seams are required.” He enjoys the full support of his employees in this respect. “Once they’ve tried it, our welders seem reluctant to use anything else”, concludes the WP production manager.