July/August 2019

MACHINE BUILDING n used in combination with movers (carriages) that can be controlled as servo axes. Each mover can be controlled individually, allowing on-the-fly product changes and opening up many possibilities for different time sequences in a production cell. “We also looked at other drives, but most did not offer the high flexibility of XTS we needed,” explains Christian Schärtl, Gefasoft’s head of project development. “Beckhoff referred us to HepcoMotion. The British company specialises in linear guide systems, and with its advanced 1-Trak linear guide system (which can be manufactured in almost every possible two-dimensional form) and high-capacity carriages, make the ideal complement to Beckhoff’s XTS system.” “The clothoid curve elements from Beckhoff and Hepco provide smooth transitions and guarantee a consistently fast and precise movement,” adds Alexander Mend, HepcoMotion’s German sales manager. “The handling of the relatively large weight on each mover is no problem. In addition, our specially developed three- bearing mover achieves minimal play around the corners, guaranteeing exact positioning in front of the cameras.” For Gefasoft, it was crucial that the combination of the two systems would allow installation of the slowest workstation in two positions, allowing parallel function of this work step and achieving the desired average cycle time of 1.9 seconds. Another important factor was the longevity and low maintenance requirements of the system, ensuring minimal downtime of the system, which is used in a three-shift operation. “We agreed a three-monthly maintenance schedule with our customer, to manage any play that has developed in the V-bearings,” Schärtl reports. Usually, the readjustment of the V-bearings is conducted while the carriage is mounted to the track. “Due to restricted access to the XTS system, we have installed a separate 300mm long length of track,” he explains, “simplifying the readjustment process and reducing the time required to maintain carriages.” The final design of the automatic optical inspection system includes a total track length of 11 metres, on which 35 movers travel simultaneously through 15 inspection stations. Each mover is numbered with an unique identifying code. When the system starts up, the tools are initialised at an RFID station that identifies the position of each mover. This allows the position of movers to be monitored throughout the entire system. As a diffuser moves through each of the stations, the results of individual inspection cameras are transmitted to a computer. Here they are evaluated and the result is returned in time for the end of the testing process, where each diffuser is classified accordingly. The system can inspect up to 46 parts every minute. “The construction of such a large production unit was new territory for us all,” says Gefasoft marketing manager, Georg Schlaffer. “It was a learning process for us, but we would definitely use Beckhoff and HepcoMotion again for similar challenges. The system has been working successfully for two years with our end-user, showing the courage to try new things can pay off.” n ,ecivreS,selaS ceMdnaecnanetniaM DON’T K Contact EMO gnireenignElacina EEP ON GOIN y for all our Electric h G ROUND A Motor and Automati ND ROUND ron elated needs ele@selas yad7,yadasruoh42 nosevlesruoedirpeW serdnasrotubirtsidera pxesraey-03revohtiW enilnOsrotoMcirtcelE ilno.srotom-cirtc .raeyasyad563,keewas naecneirepxeegdelwonktcudorpruo amrojamforebmunegralarofsrelle tuadnarotomcirtceleehtniecneire uNnidetacolssenisubnurylimafasi 808967420 en –edivorpewtahtecivresehtd .srerutcafun ewseirtsudninoitamo .erihskciwraW,notaen irtcele.ww 33 w enilno.srotom-c Gefasoft’s diffuser inspectionmachine transports items to be tested fromone test station to the next using“movers” that travel along a linear track with curved ends.