INTERNATIONAL NEWS

Grob sets dates for open house event

Machine tool manufacturer Grob is staging an open house at its Mindelheim, Germany headquarters on 21-24 March. The company will have over 30 machines on show – including four-axis and five-axis machining centres –running live cutting demonstrations. Grob’s liquid-metal additive manufacturing systems will also be in the spotlight, providing economical production of near-net-shape aluminium components. Technical partners at the event will includeSeco, Guhring, Schunk, Open Mind, Haimer, Blum, Heidenhain, Siemens, Lang and Hexagon among others.
For further information https://event.grobgroup.com/en/

REPEATABILITY OF NAKAMURA MACHINES PUTS AEROSPACE SUBCONTRACTOR ON RUNWAY TO SUCCESS

With more than 38 machine tools on the shop floor, Shannon Precision Engineering (SPE) is a major subcontract machining outfit in the Republic of Ireland. With a world-class manufacturing strategy that utilises systems like Kaizen, the SPE staff includes Six Sigma black belts and lean manufacturing green belts. To ensure production meets the stringent quality levels the company sets, it has recently invested in two Nakamura-Tome turn-mill centres, the WT150II and the SC100X2, supplied by UK sole agent, the Engineering Technology Group (ETG).

SPE is a second-generation family-run business that was founded in 1978 by Dominic Murphy senior. Starting with three manual machines in a 500 sq ft unit with one customer and two employees, the company has grown into a major player on a global scale for heavily regulated industries. Today, SPEboasts a modern 40,000 sq ft purpose-built unit with future plans for expansion and the most cutting-edge machinery powered by the latest CAM technology. Notably, the company has individual and collective training programmes to promote continuous development in its ambitious team.

The 80 employee manufacturer is AS9100 and ISO9001-certified, and the company frequently works on high-profile projects for blue-chip clients that include Airbus, Lear, Bombardier, Collins Aerospace, Liebherr, Safran, Spirit and many other leading names in the aerospace, automotive, offshore, rail and power generation sectors.

Machining everything from Inconel, titanium, Hastelloy, duplex stainless steel and Nitronic 40 and 60, as well as hardened steels, the stability and performance of the machine tools at SPE are of paramount importance. With the company winning a significant automotive order, along with major opportunities in the aerospace sector, SPE needed a new strategy in its turn-mill department.

Recalling the situation, Dominic Murphy, managing director at SPE, says: “On some projects, we’ve been struggling with repeatability when machining particularly difficult materials. For instance, we won a contract to machine electro-mechanical connections for the aerospace industry made from Nitronic 40 and titanium, and we needed to be very responsive with our changeovers and lead times. With regular batches from 200 to 500, and up to 20 different part families in the series, the project has some very ambitious cycle time targets. With tolerances of ±5 and ±10µm on many features, we didn’t want to be chasing repeatability – we needed a more robust process than we had.”

The County Clare company investigated the turn-mill market extensively and it was the Nakamura WT150II that won the day with cycle times more than 20% faster than its rivals.

“We gave ETG and other vendors a series of components as a prove-out,” says Murphy.“ETG built a machine set up around the family of components and they delivered a turnkey solution to our facility that was best suited to our requirements. We already have a lot of turn-mill centres on-site, so the Nakamura-Tome WT150II wasn’t just about cycle times. We needed a turnkey solution that could meet our ambitious cycle times and tight tolerances with relentless repeatability for long batch production – the Nakamura-Tome WT150II certainly delivered on that. Unlike many machine tool brands, Nakamura is a specialist in turn-mill centres; their pedigree stands out. We really liked the compact work envelope as well as the ability to bar feed up to 71mm diameter, which gives us options on some of our larger components.”

The twin-spindle, twin-turret turning centre provides 15/11kW and 11/7.5kW of power to the main and sub-spindle respectively. Complementing the spindle power are 5.5/3.7kW motors on the left and right tooling turrets to provide high-performance milling capabilities. With simultaneous cutting on both the upper and lower tool turrets on opposing spindles, the WT150II provides balanced turning to reduce cycle times significantly, reports ETG.

While ETG Ireland managing director Jamie Fletchmore was visiting SPE, Murphy mentioned an extremely complex automotive part that required machining on three machine tools, a four-axis horizontal machining centre and two single-spindle turning centres. With an annual output of 40,000 units, the forged automotive tensioning assembly component was permanently absorbing the capacity of all three machines. The solution was the Nakamura-Tome SC100X2.

The SC100X2is a twin-turret multi-tasking machine that utilises two tools on either side of the upper turret for superimposed machining, making it a logical solution for Swiss-style parts greater than 25 mm in diameter.Operators can also use the upper and lower turret simultaneously, turning the machine into a true twin-spindle, twin-turret machine, providing more ways to solve complex machining problems.

As a point of note, the machine’s design contributes to faster cycle times compared with other machining processes, reports the company. The SC100X2automatically unloads the workpiece once complete, minimising manual intervention and downtime. When the machine completes a cycle, the parts catcher grips the part and places it on a conveyor, removing it from the machining environment.

Alluding to the automotive components, Murphysays: “We’ve run this family of parts for more than two years and we’ve investigated the market for a solution on numerous occasions – without success. There just hasn’t been a machine on the market that can do the parts in ‘one hit’, until now.”

He continues: “The challenges have included the turning of two spindles on either side of the part that is 40-50mm off-centre. Added to this, we have to mill features that require long-reach tools to overcome interfering features. ETG has overcome this issue with the SC100X2. The machine has cut our cycle time by almost 50% from 14 minutes to 7.26, but more importantly, it has freed the capacity of two single-spindle turning centres and a four-axis horizontal machining centre whose capacity we desperately needed. We’ve reclaimed three machines and two employees, and massively improved our throughput. We are delighted with both of our new Nakamura-Tome machines.”
For further information www.engtechgroup.com

New Heckert T55 machining centre from Starrag

Starrag has announced the second – and larger capacity – member of its new Heckert range with the launch of the T55 five-axis horizontal machining centre for the multi-tasking and complete machining of workpieces weighing up to 700 kg.The machine can perform single set-up milling, turning, drilling, gear-cutting/skiving and pointing to accuracies down to 3 µmdue to the interaction between its temperature- and vibration-stable mineral cast machine bed and the double symmetrically-mounted rotary drive unit.

Drive elements such as planet carriers and wheel hub drives for commercial vehicles, agricultural machinery and industrial applications are typical applications.With pallets of 500 x 630 mm and X, Y and Z-axis travels of 850, 1020 and 1000 mm respectively, the T55 is of compact, robust design and has a low-vibration rotary drive unit specially designed for turning operations – plus a dynamic main 72 kW spindle rated at 15,000 rpm and 292 Nm. Acceleration rates are up to 10 m/sec², while rapid traverse is 80 m/min. The NC rotating table carries a rating of 900 rpm and the HSK-T100 toolholder also encourages high chip removal rates.

Although the T55 can machine components with a workpiece contour of 900 mm, chip-to-chip time is only 4.3 seconds and pallet change time is 14.5 seconds. Like its smaller stablemate (the T45), the new T55 is ergonomic, and easy and reliable to operate, while workpiece loading is easily automated by pallet storage units or robots.

Indeed, the success of a two-T45 machine cell with robot load/unload saw a drive manufacturer double productivity, halve overall machine footprint and reduce tool and handling costs by 40%. The T55 could easily mirror this performance on larger workpieces.
For further information www.starrag.com

New entry-level five-axis machining centre

At the recent DMG Mori open house held at the machine tool manufacturer’s Pfronten factory in Germany, a new five-axis machining centre was launched aimed at the entry-level market. Less than 2 m wide, the compact, competitively priced DMU 40 is capable of fully interpolative five-axis machining to within microns inside a 550 x 450 x 420 mm working volume.

Of trunnion-mounted rotary table design, the machine is based on the DMU 50 3rd Generation, of which more than 10,000 have been sold worldwide.The one-piece machine bed is made from grey cast iron, while the optimised geometry of the Y- and Z-axis slideways and the inline spindle with hydraulic clamping further ensure high rigidity. In addition, direct-drive ballscrews in the X and Y axes improve surface quality. For machining flexibility, the swivel range of the B axis extends from -35° to 110°.

The ergonomic design of the DMU 40 offers optimal accessibility to the work area. Table loading height is 800 mm and the distance from the operator to the table centre is short, while it is also possible to load components by crane. A large window and improved lighting provide good visibility. Optionally, the tool magazine may be loaded from the front.

There are three machine options with different equipment packages to meet individual requirements. The standard DMU 40 has a 12,000 rpm spindle and 24-position tool magazine, while the DMU 40 PLUS features a 15,000 rpm spindle and a tool magazine with 30 pockets, linear scales and passive cooling of all main components. Finally, the DMU 40 PRO is the most accurate and productive model, with active cooling and a 20,000 rpm spindle.
For further information www.dmgmori.com

Five-axis 30-taper VMC aimed at 40-taper market

30-taper vertical machining centre (VMC) manufacturer, Brother, has introduced a new five-axis model with a swivelling rotary table. Despite having a nominal footprint of just 1.5 x 2 m, the Brother Speedio U500Xd1 is capable of multi-face machining of components up to 500 mm diameter by 270 mm high, and weighing up to 100 kg.

Combined with a 28-position magazine for tools weighing up to 4 kg and either a 10,000 rpm/18.9 kW or 16,000 rpm/15 kW spindle with a face-and-taper interface option, Brother says that the production centre redefines machines in this class and is aimedsquarely at competing with 40-taper machining centres.

Sole sales and service agent in the UK, Whitehouse Machine Tools, points out that there is little competition to the machine on the market in terms of its operating speed. Rapid traverse is 50 m/min in X and Y, and even faster in Z, which accelerates at 2.2 g up to 56 m/min. Chip-to-chip time is 1.3 seconds, or faster still if a 14- or 21-tool magazine is fitted. Cutter exchange and axis motions take place simultaneously to minimise cycle times.

Trunnion swivel (A-axis) at 50 rpm is a -30/+120°and the table (C axis) rotates at 75 rpm. Roller gear cam mechanisms drive both rotary axes and 0-90° indexing times are 0.9 and 1.2 seconds respectively. Clamping torques are high at 610 and 500 Nm.

Lowering the power consumption of its machines has long been Brother’s aim. For a start, the electricity and air used by a 30-taper machine is only about 20% of that required by a 40-taper machine. The U500Xd1 is also equipped with a power regeneration system that reuses energy generated when the spindle motor decelerates.
For further information www.wmtcnc.com