New wire EDM range improves accuracies and flexibilities

CUT X 350. Photo courtesy GF Machining Solutions

Switzerland-based GF Machining Solutions has designed and introduced a new range of CUT X EDM machines at its Losone factory which are ‘challenging conventional thinking’. These new machines are available in two sizes — the CUT X 350 which accommodates maximum workpieces of 800 x 550 x 250mm, and the CUT X 500 which can handle maximum workpieces of 1,050 x 700 x 250mm.

Both machines are extremely accurate as they feature a new thermal management system and have optimised mechanics, which also help improve surface quality. Consistent thermal conditions are maintained by using sealed cabinet and doors that ensure cold air containment within the workspace as well as controlled air flow. By keeping heat sources away from the machine’s mechanics, the machines perform consistently without being affected by external temperature fluctuations.

The machine’s CNC collects data from an array of temperature and humidity sensors located inside and outside of the work area to further maintain ambient workspace conditions. The data drives an artificial intelligence (AI) algorithm that predicts possible thermal deformations and deviations, compensating the positioning of the X, Y, U, and V axes.

This AI-driven compensation enables high accuracy even with external temperature fluctuations — common during long cutting cycles and periods of operation. These EDMs also have the ability to switch between open and closed wire guides (sometimes known as V and round guides) respectively — on the same machine.

Superior surface finishes
Furthermore, the wire guides have interchangeable cartridges that can be switched by the operator in less than 15min (5min to change the cartridge and 10min to align the wire circuit). Open guides are more suitable for straight or less than 3deg taper angle cuts and can handle varying wire diameters without needing to be changed. Closed guides provide high accuracy, greater speed and superior surface finishes for taper cuts up to 30deg.

Pictured left: CUT X wire system. GF Machining Solutions’ CUT X machines have challenged conventional thinking

New additively manufactured upper and lower heads increase the cutting speeds of the machines. The heads reduce the distance between the guides and the part, creating better accuracy during the cut, while also increasing the amount of fluid that is pushed through to optimise flushing conditions and helping to increase cutting speeds.

Advanced software accessed by the operator through the UNIQUA human-machine interface (HMI) is used to set the necessary power settings to achieve the desired result. The machines’ Intelligent Power Generators with Direct Power Supplies (IPG-DPS) calibrate in the correct power settings with algorithms based on decades of work by GF Machining Solutions to deliver specified surface finishes and accuracies at specific speeds.

The HMI has a 19in vertical touchscreen and a full keyboard and mouse. The control supports legacy file types from older Charmilles (ISO-based) and Agie (dynamic-based) EDM machines and programs. The interface also has a graphics tool for programming both off-line and at the machine control that is compatible with major CAD/CAM programs.

Flexibility and continuous production
In addition to the series’ cartridge-based wire guides, flexibility and continuous production are achieved through the incorporation of automatic wire changer (AWC) technology that includes two identical, symmetrical wire circuits. With the AWC, operators can use a thicker wire for a fast, aggressive main cut followed by a thinner wire to trim-cut small corner contours and radii. The technology also enables the use of two wires of identical diameter, with and without coating, to optimise cutting speeds during the main cut and surface finishes during the trim cut.

To prevent wire breakage, the system uses Spark Track technology and Intelligent Spark Protection System (ISPS) to constantly monitor and evaluate the position of each discharge between the wire and workpiece in real time against set thresholds. If the discharge concentration exceeds the threshold, ISPS automatically adjusts the spark energy — maintaining the optimal wire condition and cutting speeds. The machines have 90deg corner doors that automatically open for operator entry and accessibility to the entire work area. The doors also enable robotic loading/unloading.

Further lights-out productivity is possible thanks to the integrated Z-axis touch probe that automatically measures the top surface of the workpiece and aligns the wire perpendicular to this new plane, and an automatic slug management system that removes slugs to a dedicated bin.

Wire management is also automated for autonomous operation with automatic wire threading, an integrated wire chopper that reduces downtime, and a double-wire spool with AWC technology.