FEATURE ON CNC LATHES AND TURNING CENTRES

Versatile solution for large-part machining

Okuma’s new two-saddle lathe – the LU7000 EX – which is available in the UK from NCMT, is equipped with a high-power spindle and allows for the turning of large workpieces.

Providing a wide variety of features and modifications, the four-axis lathe can be customised in accordance with the client’s individual requirements, making it suitable for a multitude of applications.
Especially when turning large and heavy workpieces with diameters of up to 900 mm, Okuma’s LU7000 EX reveals its true potential. Equipped with a bed that is 2 m long, even very long parts can be machined, aided further by a self-travelling tailstock. These specifications make the LU7000 EX a good choice for the manufacturing of oil and gas parts.
The machine is equipped with two turrets that can be utilised simultaneously. Said to be a first for this class of machine, the lathe offers a milling turret which allows for a high chip removal rate of up to 120 cm³/min. For ideal cutting conditions, manufacturers can choose from different main spindles featuring sizes ranging from a bore diameter of 200 mm with a maximum spindle speed of 1500 rpm, to a bore diameter of 560 mm with a maximum speed of 350 rpm.
When designing the LU7000 EX, Okuma also focused on achieving high dimensional accuracy. The lathe’s high constructional rigidity, but also Okuma’s Thermo-Friendly Concept contribute to this goal. The application avoids any generation of immoderate heat during the manufacturing process, detects changes in temperature and compensates for thermal deformation. This way, inaccuracies due to thermal fluctuations can be prevented.
For further information www.ncmt.co.uk

£500k investment at NDB ups productivity

Willenhall-based NDB Engineering, a specialist subcontract fastener machining business, has spent £500,000 in the past 12 months on the latest turn-milling technology from Citizen Machinery UK.

This budgeted spend, funded through Citizen’s tailored finance package, covered two Citizen Cincom L20-VIIILFV sliding-head turn-mill centres and a Miyano BNE-51MSY fixed-head turn-mill centre (pictured), plus Citizen’s Alkart CNC Wizard programming aid, all of which now form a critical part of the future business strategy. As a result, opportunities are being created to gain higher productivity and spindle utilisation, with ever greater confidence in quality being maintained.
Managing director Andy Williams says: “These machine installations have also saved us having to seek outside help to satisfy our growing order book, as we were very concerned about loss of direct control, especially over quality if we used outside subcontractors.”
Joint director Rebecca Dainter adds that over the previous 15 years the company had installed sliding-head machines but swarf control was a constant attention-seeking headache. “It restricted output and, without care, could easily degrade quality and decimate our productivity targets,” she says.
She follows on to reveal that when Low Frequency Vibration (LFV) technology became available from Citizen, the company immediately saw the potential to achieve greater security and control during the machining of difficult materials. “Swarf nesting problems have disappeared. In addition, we have improved our productivity by having the confidence to run unmanned, and on many parts can go through the night, giving us a massive leap in capacity with the added bonus of one setter/operator tending three machines.”
For further information www.citizenmachinery.co.uk

Tornos plays right tune for guitar specialist

Top guitar players and metal-cutting experts share a common passion: the search for the last micron and the perfect sound.

Both of these factors can be found at Schaller, a company that produces precision mechanical components for electric guitars. To achieve the accuracy required, Schaller relies on CNC automatic lathes from Swiss manufacturer Tornos.
Schaller GmbH is a German manufacturer of hardware for musical instruments and is headquartered in Postbauer-Heng, near Nuremberg. The company develops, produces, markets and sells machine heads, bridges, vibrato systems (so-called tremolos), strap locks and other guitar accessories on a global scale.
A look at output levels reveals that the company is actually a highly prolific manufacturing enterprise. In the online shop, customers will find about 19,000 products and 160 end assemblies that consist of up to 500 individual parts having eight different surfaces each. The fact that Schaller supplies more than 1.5 million products per year is testament to factory manager Dominik Weininger and his team.
The company possesses two Swiss GT13 and two Swiss DT26 machines. For Schaller, the technical features of the GT 13 and its six-axis kinematics are the prerequisites to meet all challenges associated with the production process. The Swiss GT13 is intended for diameters up to 13 mm and has six linear axes and two C axes. These axes can be equipped with up to 30 tools, 12 of them being driven tools.
The Swiss DT26 boasts a tried and tested kinematic structure with five linear axes. Spindles can reach a power rating of over 10.5 kW. Moreover, the Swiss DT 26 is no longer restricted to mere turning and milling tasks, but can be equipped with various tool holders.
The Tornos machines at Schaller are running 24 hours a day, five days a week.
For further information www.tornos.com

100 options for new lathe

New from DMG Mori is a universal turning centre, the CLX 550, featuring robust construction, a 33 kW (40% DC/3250 rpm/630 Nm) spindle and the option of a Fanuc 3D control instead of the standard 19” SLIMline multi-touch control panel with Siemens 840D solutionline and Operate 4.7.

The lathe joins two smaller models – 350 and 450 – to expand a range that was first announced at the AMB 2016 show in Stuttgart.
Able to turn components up to 480 mm in diameter by 1225 mm long, the CLX 550 offers users a larger work area in a compact footprint of 7.4 sq m. The cast-iron bed ensures rigidity, minimises vibration and allows improved chip evacuation.
Large ballscrews, sturdy spindle bearings and a VDI 40 turret with 12 stations, live if required, ensure high productivity and accuracy, which is further promoted by feedback of axis positions via linear scales. When configured as a bar automatic, the machine produces parts up to 80 mm in diameter, or alternatively 102 mm. In terms of precision, circularity of less than 3 µm is quoted.
A choice of over 100 hardware and software options enables application-oriented specification and upgrading of the CLX 550. In addition to the optional larger bar capacity and possibility of choosing a 120 mm Y-axis, VDI 30 or VDI 50 turrets are available, as well as a tailstock and a steady rest, both of which can be programmable to facilitate the manufacture of crankshafts, for example. If a counter-spindle replaces the tailstock, six-sided machining of complex workpieces can be carried out in one hit.
For further information www.dmgmori.com

Latest precision lathe generation

The sixth generation of precision turning centres from Spinner – the MicroTurn series – was displayed for the first time at the AMB 2018 show in Stuttgart recently.

Available in the UK through sole agent Whitehouse Machine Tools, the MicroTurn is built in two sizes and is capable of producing components to within 5 µm dimensional tolerance in series production.
To enable this degree of precision, including when hard-turning and micro-finishing components, what Spinner describes as ‘disruptive influences’ from turrets, Y axes and unnecessary heat sources, have been minimised.
The concept is based on the company’s previous precision lathes, which employ a two-axis spindle head on a compound slide, in this case moving 600 mm in X and 350 mm in Z, with balanced thermal characteristics for fine positioning. On the MicroTurn, the spindle operates in conjunction with a static, linear tool carrier integrated into the vertical machine bed (L-Version).
Recognising that companies producing smaller batches of parts need greater flexibility and fast set-up times, Spinner has provided a number of options. One is a BMT45 turret with a ±50 mm Y axis and 12 stations (optionally driven at 8000 rpm), which can be added at the bottom of the working area (LT-Version).
For extra versatility, the BMT45 turret can be joined at the top of the working area by a 15 kW/12,000 rpm pivoting B-axis milling spindle with ±50 mm of Y-axis movement and an HSK40 interface (LBT-Version). The spindle can be served with cutters exchanged from a 33- or 72-station tool magazine. There is also an LTBS-Version with an opposing counter-spindle, identical to the main spindle, for simultaneous parallel machining or synchronous workpiece transfer.
For further information www.wmtcnc.com