Warwick Machine Tools is the exclusive UK and Eire agent for Taiwan's Excetek Technologies wire-cut EDM machines.
The entry level V350G machine offers a cost saving of between £20,000 and £25,000 against any equivalent size Japanese or Swiss machine tool, with the price including training and installation. Fitted with a 600 litre tank, it is capable of accommodating parts up to 700 by 500 by 215 mm and weighing up to 450 kg. This fully specified wire machine has U and V axis travels of 80 mm and there's a ± 30° taper capability, and an accuracy of 3 micron over 100 mm.
There are currently around 35 machines operating in Europe, and WMT has an entry level V350G machine for customer trails and demonstrations in its showroom.
Established in Taiwan in 2006, Excetek Technologies focuses solely on wire-cut EDM. Excetek's senior management team has over 150 years' experience of wire EDM technology between them. And, driving the technology forward, the Japanese technical manager, Mr Matsuo, has over 45 years experience in the wire cut sector. All machine tool research and development is done in-house, and the software and high frequency pulse control generator have been created by Excetek.
Even the CNC system has been developed by the company, using Windows-based 64-bit architecture with a 15 inch LCD touch-screen for programming. Excetek says it is easier for operators to understand as they are already familiar with the 'look and feel' of the Windows environment. It cuts down the training time required, so one day's training is all that is required before the operator is competent to program and run the machine. Programming can be done using standard ISO G code or Excetek's Icon Assistant conversational software, which uses the controls extensive database of cutting technologies.
While the cutting speed of every wire EDM machine is limited by the laws of physics and set by the thickness of the raw material being cut, it is a manufacturer's corner control that defines its machine accuracy. Excetek's software ensures the motion control and spark generator work together for the optimum power ramping and compensation dwell on corners, avoiding wire twist and reducing corner 'washout'.
The control system can also apply offsets to allow for any misalignment during workpiece loading. Before machining an edge finding operation sets the actual position of the raw material, and the control software resets its datum points accordingly.
All the standard range of wire EDM machines feature a C-frame structure designed using FEA software to provide exceptional accuracy in the linear axes movements and to minimise any thermal influence. The AC servo motor driven C1 class ball screws are cryogenically treated to minimise the thermal effects of the machine's ambient operational environment, with high accuracy linear scales fitted for positional feedback.
Also developed by Excetek, the automatic wire feed and threading system is produced in-house. Designed to provide continuous unmanned operation around-the-clock, the AWT offers the ability to thread the wire at the point of the breakage. An automated annealing system straightens the wire so that it can be threaded at the break point during machining with almost 100% reliability and without the need to return to the start position. Submerged wire threading is possible, which removes the need to drain and refill the tank. A water jet assist system is available for automatic wire feeds on tall workpiece.
As well as standard wire machines, Excetek design and manufacture bespoke EDM solutions to address customers' requirements. These include a machine with a 1,000 mm Z-axis for a Japanese customer. Believed to be the first in world, the machine is still capable of holding an accuracy of 60 to 70 micron.