New wire cutting EDM technology

The new Excetek NP Plus series of advanced CNC wire EDM machines, supplied exclusively by Warwick Machine Tools, offers a giant ‘green’ leap forward for machine shops and engineering businesses. Equipped with high precision linear motors and an extremely efficient generator developed to cut energy consumption to the bare minimum, each model in the NP Plus range provides key business benefits.

With the launch of the new Excetek NP Plus series of CNC wire EDM machines, the company is combining the very latest technology to offer machine shops a substantial case for investment. Fitted with high precision linear motors, a Green Sparking generator, low energy pumps and a new efficient water chiller based on advanced invertor technology, the NP Plus series not only reduces energy consumption but they also cut significantly quicker.

The Green Sparking generator runs through an energy-saving discharge circuit. It incorporates a sink energy recovery system that recovers energy (in a similar way to energy recovery on Formula One race cars). When coupled with high-speed discharge pulses, this innovative circuit not only increases machining speed by up to 25%, but along with the other energy efficient features on the machine reduces overall power consumption by up to 35%.

An ECO Mode optimises fine finishing discharge performance by reducing the number of machining passes required compared with previous models, resulting in improved surface accuracy. It also features automatic compensation for brass wire wear, helping to minimise wire consumption. The new generator achieves a fine surface finish of Ra 0.5 in three cuts and Ra 0.3 in five cuts, compared with a finish of Ra 0.7 and Ra 0.35 for the same number of cuts using the previous generator.

Additionally, peripheral systems such as the chiller used for the die electric fluid and linear motors, are intelligently controlled to operate only when needed, further lowering overall energy usage.

“The combined power saving is impressive,” states Technical Manager Paul Barry. “A 35% reduction in energy consumed adds up. Over a year it represents an annual carbon emissions reduction of 4,310 kg and electricity saving of almost 9,000 kWh*. With current prices at nearly 30p per kWh, the savings quickly make a strong case for businesses looking to invest in ‘green technology’ that provides real world benefits.”

An onboard energy consumption monitoring system lets any business see for itself. Engineered for energy efficiency and carbon footprint reduction, this system offers real-time energy monitoring, historical data analysis, and parameter management to help optimise overall energy usage.

Real-time monitoring continuously tracks voltage, current, power, power factor, machine status and three-phase power consumption with second-by-second updates. While energy data analysis provides daily and monthly energy consumption reports, automatic carbon emission calculations and clear energy consumption insights. The latter provide:

• Daily and monthly analysis – pie and bar charts visualise energy distribution trends over a period of up to 24 months.
• Energy trend charts – displays real-time and historical power consumption with customisable comparison options.
• NC machining history – logs energy usage for each NC machining process and converts it into cost data to support more accurate financial planning.

As Paul reveals: “Accurate energy data from this system empowers users to make smarter, more effective energy saving decisions.”

The structural castings and machine frames have been designed and developed using the same trusted FMEA system as the established Excetek G Plus range. However, the new NP600L Plus features a fixed table with the linear motors moving the gantry and wire feed.

“This allows the maximum amount of load on the worktable, up to 800 kg,” reports Paul. “With a static workpiece and moving wire feed the cutting speed can be optimised – reduced by 25% – with no detrimental impact on volumetric accuracy or repeatability. Both are better than +/- 2 micron.”

Interested parties can see the new Excetek NP Plus series CNC wire EDM machines in action at Warwick Machine Tools’ showroom.

*These figures are based on Excetek’s internal processing data. Actual results may vary depending on specific machining conditions. The simulation is based on the following scenario: 250 working days per year, two shifts per day, 8 hours per shift, with a 70% machine utilisation rate.