FEATURE ON CNC MILLS & MACHINING CENTRES

Future is bright for Bronte Precision Engineering

Mills CNCrecently supplied Bronte Precision Engineering, a Bradford-based precision subcontract specialist, with a new heavy-duty three-axis vertical machining centre.The machine, a box guideway Mynx 6500/50 II manufactured by DN Solutions, replaced an older Daewoo Mynx 540 machining centre supplied to Bronte by Mills CNC in 2004.

Since its installation, the Mynx 6500/50 II with FANUC 0iMP control and gearbox-driven 6000rpm (BT 50) high-torque spindle has been put through its paces machining a range of high-precision complex components. These parts include valve-type components (for subsea applications) made from Inconel castings for a long-standing customer and manufacturer of industrial pumps.

Programmed offline and machined in small batches, the pump valve components are approximately 400 x 300mm in size, involve long and intensive roughing and finishing operations, and are characterised by their tight tolerances and stringent surface finishes. Cycle times with the new Mynx 6500/50 II are significantly faster (up to 50%) than those achieved using the Mynx 540, vindicating the new machine acquisition.

Says Bronte Precision director Steven Haigh:“The Mynx 6500/50 II is a powerful, accurate and flexible machining centre that, in just a few short weeks, has proved its worth. Its rigidity, box guideway construction and BT 50 spindle with through-spindle-coolant capability has enabled us to improve our productivity and process efficiencies.The ability to ramp up speeds and feeds and take more aggressive depths of cut have shortened cycle times.”

He adds: “The machine is still being ‘bedded-in’ so to speak, but I’m confident that once we’re more familiar with its onboard technologies, we’ll hit tolerances of ±0.03mm on selected features.”

More information www.millscnc.co.uk

Starrag Machine Achieves Unprecedented MRR

The Starrag S1250 HD five-axis machining centre with hydrostatic guides, which is suitable for machiningtitanium thanks to its rigidity and damping attributes, achieved astonishing results in performancetestsperformed by Starrag at its main plant in Rorschacherberg. Using a carbide cylindrical endmill (40 mm diameter, 18 teeth), the machiningspecialist achieved a metal removal rate (MRR) of 1516 cm3/min. Starrag estimates this MRR is potentially a world record in titanium machining.

Even the prototype of the Starrag S1250 HD proved to be a highly efficient machine for cutting titanium structural components. Two years ago, in roughing tests, the machining centre with hydrostatic guides achieved up to three times the MRR of the Starrag STC 1250 version featuring roller bearings. The improved damping and dynamic performance also ensured high precision and surface quality during finishing.

For the series-produced machine, Starrag engineers imparted a few additional modifications to increaseMRR further and reduce tool wear. As the most critical factors in this context are rigidity and damping, Starrag made the machine and column structure even more sturdy.

Another revision concerned the rotary table, which is now designed as a gearbox version. With a high torque of 25,000Nm and a clamping torque of 32,000Nm, it fully meets the requirements of titanium machining. In addition, the compact swivel milling head was enlarged on one side, creating space for a 50% stronger Aaxis with 12,000Nm of torque and 20,000Nm of clamping torque while retaining accessibility.

In terms of the work spindle, a new feature is the HSK-B160 interface, which ensures high tool rigidity when cutting large depths.

Airbus has already ordered five Starrag S1250 HD machines for its Varel site in Germany.

More information www.starrag.com

Five-Axis Machining Centre Options Include Ultrasonics

Occupying just 3.8 sq m of space on the shop floor, a compactfive-axis machining centre with a working volume of 220 x 370 x 290 mm is now available from DMG Mori. The new DMU 20 Linear can meet a wide range of applications, from the micro-machining of watch components, through EDM electrode and impeller production, to die and mould making.

A rigid, FEM-optimised cast bed and thermo-symmetrical gantry design have been coupled with Magnescale axis position measuring systems to ensure long-term stability and machining accuracy to within single-figure microns.

The A-axis trunnion swivels from +130 to -93°, allowing flexible machining strategies and enhancing the operator’s view of the workpiece. The C-axis table rotates at up to 150 rpm, optionally 1500 rpm, while offering a positioning accuracy of two arcseconds. Zero-point clamping is standard, with the customer able to choose Erowa, Schunk or another make. There is also provision for the vacuum clamping of delicate or thin-walled workpieces.

The machine features a Fischer spindle (HSK 32, 42,000 rpm) as standard, although HSK 32 or HSK 40 spindles up to a maximum of 60,000 rpm are available. If elevated levels of precision are necessaryin combination with long running times, a shaft-cooled version is available for the HSK 40 variant. The tool magazine offers 26 pockets, optionally up to 60 tools, suitable for flexible production requirements with frequent tool changes.

For machining hard, brittle materials such as glass, Zerodur or technical ceramics, the machine is available as a third-generation Ultrasonic 20 Linear. In this model, tool rotation is superimposed with an additional ultrasonic oscillation, reducing the force generated by the tool during machining by up to 50%.

More information www.dmgmori.com

Positive investment for precision subcontractor

Mills CNChas recently supplied NextGen Precision, a precision subcontract specialist based in Blackburn, with a new high-performance three-axis vertical machining centre.The machine, a fourth-generation DNM 5700 from DN Solutions equipped with Siemens 828D control, was installed at NextGen’s machine shop in July 2025. It is the first machine tool acquired from Mills CNC in the company’s 44-year history.

NextGen Precision is a successful family-owned business that employs five members of staff.

The company is committed to continuous improvement and, as such, regularly invests in its people, plant and machinery.NextGen is currently undergoing a strategic review and revamp of its machine shop in order to strengthen the company’s supply chain relationships and facilitate organic growth opportunities with existing customers in the highly-regulated aerospace, security and nuclear sectors. The business is also looking to win business from new customers.

In spring 2025, a new customer operating in the security sector approached NextGen Precision to discuss its requirements for high-precision components supplied in volumes up to 2500 per month.

Says Stephen Fairbrother, NextGen Precision’s co-owner and director:“Although the new business was clearly welcome, we could see the quantities involved would put our existing machining capacity and capabilities under pressure.As a result, we made the decision to invest in a new high-performance machining centre and run it in tandem with one of ourexisting machines.”

Says Mark Fairbrother, Stephen’s brother and fellow co-owner and director:“Before we approached the market to talk to individual machine tool suppliers, we drew up a detailed checklist for the new machine.”

The checklist included the following ‘must have’ features: a rigid design and construction; a powerful, high-torque, directly-coupled spindle; a good-sized worktable; and a generously sized and fast tool changer.

After reviewing suitable machines, NextGen Precision visited Mills CNC’s facility in Leamington where it was introduced to the fourth-generation DNM 5700.

“We liked and valued their approach,” says Stephen. “Not only could they ‘customise’ the DNM 5700 to meet our requirements, they could also arrange a flexible finance solution install the machine from stock in double-quick time.”

He concludes: “We’re delighted with our newDNM 5700, which is fast, accurate and flexible.We’ve also developed a great working relationship with Mills CNC.”

More information www.millscnc.co.uk

Affolter Group debuts AF140 precision gear hobber

The Affolter Group, a world specialist in high-precision gear hobbing solutions, has launched its state-of-the-art AF140. The company’s newest gear hobbing centre is designed for small gears up to 40 mm in diameter and a maximum module of 1.0 mm. Positioned between and replacing the AF90 and AF100, the AF140 delivers the strengths of its predecessors while introducing next-generation automation and connectivity features.

Affolter’s AF140 was developed in close collaboration with users and industry partners to meet the growing demand for simplicity, compactness, versatility and ingenuity in gear hobbing. Designed primarily for the watchmaking sector, the machine is equally suited for precision applications in micromechanics, aerospace, automotive, micromotors, robotics and medical technologies.

“With the AF140, we’re offering our customers a perfect balance between performance, flexibility and innovation,” reports Mikael Affolter, head of sales at Affolter Group. “Its compact footprint makes it ideal for workshops where every square centimetre matters, while its compatibility with existing loaders and the option of a robotic arm provide new levels of automation and productivity. Combined with remote service features, the AF140 represents a true step forward in precision gear hobbing.”

The AF140 reaches cutter rotation speeds of up to 16,000 rpm and workpiece rotation speeds of up to 5000 rpm. A new and customisable robotic arm option for automatic loading and unloading significantly boosts the productivity of the AF140, enabling easy automation and reliable 24/7 production. At the same time, the machine remains fully compatible with established loaders such as W20, W25, W31, AF45, deburring units and more. Built on the powerful Pegasus CNC platform, the AF140 provides digital integration with IO-Link sensors, simplified commissioning, and advanced remote service for real-time support and updates.

More information www.affoltergroup.ch