Marginal Column

Four spindles counter standstills

July 2013

 

An Italian manufacturer of custom-engineered equipment, Sistech S.r.l., has developed a machine tool aimed at flexibility. Its forte is minimizing the setup times needed prior to machining.

 
 
Photo | Sistech s.r.l.

Photo: Sistech s.r.l.

Thanks to components made by Rexroth, the T0.5 processing center is far down the track – while other machines are still on the starting blocks. Tailor-made solutions, numerous uses, simple operation – and economical, to boot. The demands mechanical engineers are expected to fulfill are enormous. As sophisticated and optimized as a machine might ultimately be, periods of standstill are and continue to be efficiency’s biggest enemy. One good example is the setup time required when changing tools. The machine is stopped, production is suspended, the clock continues to tick away the expense. One custom machine manufacturer – Sistech – has succeeded in markedly reducing this particular cost factor. With its model T0.5 this company, founded in Brendola in northern Italy in the year 2000, is making available a machining center that can process a wide variety of materials, including light alloys, steel and cast iron.

A winning team of four

All this is made possible by four machine spindles that can accept up to 120 different tools. Those spindles speed up throughput time and lower the costs per piece. The clue? During ongoing production, the spindles are always used in pairs. While the first two spindles machine the first two workpieces, the others change out the tool.

“When we started developing the T0.5 two years ago, we tried to employ every possible resource and concept to set us apart from the competition,” recalls Pierangelo Nardon, CEO at Sistech. The results are proof of the success. During a processing cycle involving 30 tool changes, productivity rises by 60 percent when compared with other machines. “The more frequently we change out the tools, the more evident the benefits become,” Nardon explains.

Classy mass production

The T0.5 machining center embodies all the properties needed for superb precision in mass production. In addition to its wide variety of uses in machining, it is also true that the CNC controls make for simple changeover and quick machine setup – a matter of real significance. With as many as five axes, the machine can process workpieces from every conceivable angle. And since these are all under individual control, the parameters for each individual axis can be modified even during the machining process. That increases flexibility and reduces the reject rate, since machining faults can be corrected as soon as they appear.

It’s the mix that counts

Rexroth technology is responsible for trouble-free drive. IndraMotion MTX Advanced is used for the CNC controls. The IndraDrive, with the SafeMotion function, delivers the drive power while motors from IndraDyn series S, T and H drive the shafts and spindles. These are complemented by roller rail systems, a variety of hydraulic components, and sophisticated hydraulic system concepts. And finally, variable-speed pump drives guarantee energy-efficient power for the hydraulic system. “These Sytronix systems combine the reliability of high-performance hydraulics with energy efficiency and the dynamics of compact electronics,” explains Paolo Lonati, sales engineer at Bosch Rexroth. The configuration of the Rexroth products to create this custom system was tailored to the specific needs that Sistech had formulated. It was developed in close collaboration with Sistech, an arrangement that went far beyond the usual relationship between the supplier and the user. “Since this was an entirely new application, our ‘development coalition’ was very intense. By sharing our experiences, we were able to further optimize our own system and, using Rexroth components, could achieve optimum results,” Pierangelo Nardon stresses.

A trend-setting machine

“It is not easy to find a company like Sistech – one that is able to provide this kind of innovation so regularly and so effectively. The new machining center clearly shows how successful such cooperation can be. The model T0.5 machining center has everything it needs to become a benchmark in this segment of the market,” Lonati adds. In the meantime it has also been awarded patent protection. “This confirms that we have developed a cutting-edge machine, something that has not been seen on the market for a long time now,” Nardon notes.