TPT November 2011

T echnology U pdate

All-in-one machine controller simplifies development of plasma tube cutter

the angled end pieces for an elbow pipe and then assembling them – a task that previously took about 15 minutes in total – can now be accomplished in around 4 minutes. The tube being cut is mounted in the machine with its top end held in a rotating pneumatically driven clutch assembly. The plasma cutting torch is moved up and down as the tube rotates, at a rate that determines the severance angle or the size and shape of the hole being cut. Both the main rotational axis and the plasma torch height axis are powered by Baldor BSM series AC brushless servomotors driven by Baldor MicroFlex digital servo drives, and employ interpolation to secure a constant cutting rate regardless of the profile of the cut or diameter of the tube. The machine can handle a wide range of tube diameters, from 90 to 350mm, with wall thicknesses up to 1.5mm. The tube cutter also uses three Baldor stepper motor driven axes. Two of these control the position of a pair of guide rollers, which support the tube during the cutting process and are driven closer together or further apart

A NEW plasma cutting machine for flue pipes has been developed by Techserv Cutting Systems, a manufacturer of CNC profile cutting systems. Advanced interpolated motion of the cutting system is used to increase production throughput, using an economic real-time machine control module from Baldor. Capable of cutting aluminium and stainless steel flue pipes at any angle, as well as holes of any shape or size, the plasma tube cutter completely automates this aspect of manufacturing. For example, elbow pipes have traditionally been produced by cutting complex shapes from flat metal sheet, which are then rolled and welded before assembly. This time-consuming multi- stage fabrication process requires considerable movement of work pieces around the factory. The new cutter dispenses with the need to pre-cut complex shapes. Instead, the flat metal sheet is rolled into a tube and seam welded, then each tube is successively loaded into the machine. The entire cutting operation is handled autonomously; a simple angled cut takes a matter of seconds. Cutting

depending on the diameter of the tube. They also move aside automatically during the tube reload phase to facilitate operator access. The third stepper-driven axis dynamically varies the distance between the plasma torch head and the wall of the tube during the cutting process, to provide optimum performance. All five electrical axes are controlled by a Baldor NextMove ESB-2, a compact real-time machine control module that receives commands direct from an on-board PC-based CNC system developed by Techserv specifically for tube profile cutting applications. The CNC system software runs under Windows XP, with all operator information presented on a large, touch- sensitive, full colour HMI. Baldor’s NextMove controller provides all the control functions for the machine’s five servo and stepper motion control axes, with even the base model capable of accommodating a further two axes if required for future machine variants. The controller also features extensive built-in I/O capabilities, again with expansion options. According to Techserv’s technical director, Mike Cowley, “Baldor’s high- level Mint programming language helps us to develop motion control programs for custom applications like this very quickly. Integrating the NextMove controller with our front-end CNC system was also straightforward because it uses the same API naming conventions as ActiveX commands.”

Baldor Electric – USA Fax: +1 479 648 5792 Website: www.baldor.com Baldor UK Ltd – UK Fax: +44 1454 859002

Email: sales.uk@baldor.com Website: www.baldor.co.uk Techserv Cutting Systems – UK Fax: +44 1924 458630 Website: www.techserv.co.uk

Baldor’s NextMove ESB-2 real-time controller provides control functions for the tube cutter’s motion axes

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N ovember 2011

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