FEATURE ON CNC MILLS & MACHINING CENTRES

Autonomous five-axis machining around the clock

Since 1983, Peter Josef Klein Feinmechanik GmbH (PJK) – a 50-employee subcontractor based in Sankt Augustin near Bonn, Germany – has been producing precision components and assemblies from aluminium, titanium, stainless steel and high-performance plastics for customers principally in the medical, food and aerospace industries. For metal cutting, the company mainly uses machine tools from DMG Mori, including seven DMU 60 eVo machining centres, all of which feature automation.

Two of the machines are connected via a pallet handling system, which has 40 locations and can accommodate 300 fixtures that are exchangeable between pallets. An Erowa MTS zero-point clamping system serves as the basis for the flexible, automated cell.

Second-generation Peter Klein, who runs the company with his brother Julian, says: “Our main challenges are the extreme quality customers require and the high degree of competitive pressure. Our components are accurate to within microns, while at the same time we also have to continuously check and optimise our processes.”

One way of meeting these challenges is autonomous manufacturing, with PJK using automated cells to maximise machine utilisation since 2011. It means an employee can operate several machines during day shifts, while the company gains extra production output during unmanned running overnight and at the weekend.

To ensure precise and dynamic machining, the majority of DMG Mori machining centres on site at PJK are fitted with linear drives.

Says Julian Klein: “The machines produce our range of components efficiently by five-axis machining and meet our tight tolerance requirements. Customers stipulate accuracies down to single-figure microns, which we have to hold consistently. Five-axis machining contributes to our ability to control this level of quality, as the number of manual re-clamping operations is reduced or even eliminated.”

More information www.dmgmori.com

SW to launch BF 12-21D at EMO 2025

The right solution for every application, from small to large series production: at this year’s EMO 2025 exhibition in Hanover, Schwäbische Werkzeugmaschinen (SW) is presenting a new machine tool on stand C05 in hall 12. With the BF 12-21D, SW says it is responding to the current trend in automotive engineering toward die-cast aluminium body parts. The BF 12-21D is suitable for high production volumes, in particular for the fast machining of frame and structural components.

“In automotive engineering, we’re seeing a clear trend toward the use of aluminium die-cast parts in vehicle body construction,” explains product manager Michael Kreuzberger. “These parts require less manufacturing precision than, for example, gearbox or stator housings. With the BF 12-21D, we offer an economical and dynamic machine concept for precisely these applications.”

The BF machine series differs from other SW machines in its structural design: to fit specific market conditions it features a hybrid axis configuration, utilising a linear drive for the X axis, while the Y and Z axes are driven by ball screws. SW also relies on proven twin-spindle technology to meet high productivity requirements. With two three-axis units and one spindle per working area, the BF 12-21D can replace two conventional single-spindle machines and achieve higher output with a smaller footprint, reports the company. When components are changed in one working area, the second spindle in the other working area can be used to achieve even higher productivity.

SW will also exhibit an established machining centre at EMO. The BA 442 is one of SW’s fastest and most sustainable machines. With four spindles, it offers high effectiveness per square metre of space while also being energy-efficient.

More information www.sw-machines.com

Traditional homeware made on modern XYZ machines

Capacity in the Suffolk workshop of Jim Lawrence Traditional Ironwork is mainly taken up by producing parts for a range of lighting products. With recent growth, particularly during the pandemic when the company virtually ran out of stock, the focus of company owner Jim Lawrence is firmly on making investments to maintain high productivity and efficiency. This is among the reasons he recently approached XYZ Machine Tools to look at more effective ways of manufacturing the housing for the company’s popular ‘Harbour’ range of outdoor lights.

Production manager Chris Moore says: “We were machining these housings in six operations with the added complication that they are coming from a brass casting. The aesthetic appearance of these lights is critical to our customers, so ensuring that the two parts fit together correctly and the wiring inlets are central to the boss is of paramount importance.”

Having provided drawings and samples to XYZ, the applications team looked at how the cycle time could be reduced and that every single one of the housings machined looked pleasing on the eye. The team proposed an 800 HD vertical machining centre fitted with a Nikken 5AX-201 five-axis table and Renishaw OTS tool setting probe, along with an OMP 40 spindle probe arrangement.

“With the help of XYZ, we’ve reduced the machining of these parts to two operations,” reports Moore. “Having produced a fixture to hold the part on the bed for op 1, the parts are then located on a fixture which sits in the tilt/rotary table where [for op 2] we can machine not only the main face of the housing but also the features located around the outside in the same set up.”

More information www.xyzmachinetools.com

New Heckert large-machine series on its way

Starrag, which unveiled its new large-machine series in November 2024, says the four planned Heckert models will be launched and presented to the market in stages throughout 2025.

The company’s HPMS (High Performance Machining Systems) business unit, which includes the Chemnitz and Rorschacherberg sites, has developed a new large-machine construction kit from which new machining centres can be derived.

Development engineers considered the latest technical aspects when redesigning the large Heckert machines. For example, the frame components, such as the beds and columns, were optimised for thermal symmetry. If the ambient temperature changes, the core components expand or contract evenly in all directions. This behaviour is predictable and correctable. The chip fall in the area between the work spindle and the workpiece has also been improved so that hot chips have minimal opportunity to transfer heat to the workpiece or the machine.

An important advantage of the new machines is the improved productivity. The decisive factor here is an increase in the diameter of the ball screws from 63 to 80 mm. A further stiffening of the structural components complements this improvement. As a result, users can achieve even higher cutting values, increase chip volumes and ultimately reduce machining times. The machine has also become faster. Instead of a 40 m/min rapid traverse rate, it now enables 50 m/min, reducing non-productive times.

The approximately 20% smaller footprint is another benefit in light of high floor space costs. This reduction is primarily due to the repositioning of an energy chain, which enables further integration of the chip conveyor into the machine.

More information www.starrag.com

DMG Mori releases DMX five-axis machines

Based on the robust design of DMG Mori’s DMV series vertical machining centres, the company has developed its new DMX 60 U and DMX 80 U for workpieces weighing up to 300 and 350 kg respectively. With travels of 600 x 600 x 510 mm for the DMX 60 U and 800 x 600 x 510 mm for the larger model, the competitively-priced, 3+2 axis machining centres with their swivelling rotary table are suitable for producing complex components.

The machines feature a design based on a monolithic machine bed and massive castings, providing up to 50% higher static rigidity compared with their predecessors. Combined with wide roller guideways in all axes, DMG Mori says it ensures excellent stability during operation. The design also enables dynamic machining and rapid traverse rates of up to 42 m/min, some 40% faster than predecessor machines. Moreover, the speed of the rotary B axis and C axis for positioning parts has been raised by an even higher percentage, from 6 to 10 rpm.

Comprehensive, multi-sensor temperature compensation ensures thermal stability and consistently precise production, while direct drives and linear scales in the X and Y axes guarantee high positioning accuracy.

The energy-efficient production centres are suitable for a variety of applications thanks to a choice of spindles, starting with the 12,000 rpm inlineMASTER spindle as standard. SpeedMASTER spindles with a high torque of up to 200 Nm or a speed of 20,000 rpm are optionally available.

The standard BIG PLUS face-and-taper tool-holding interface provides additional stability and accuracy during machining. Customers can choose from different tool magazine options with 30 to 120 pockets.

More information www.dmgmori.com