FEATURE ON CNC LATHES AND TURNING CENTRES

Latest Y-axis, sub-spindle turning centre

The next-generation Y-axis, sub-spindle Doosan Puma 2600SY Mk II turning centre series is now available from Mills CNC. Although the new machines are equipped with a 10” chuck, unlike Puma 2600SY Mk I models, they have a larger 81 mm bar diameter capacity. The machines are also supplied with built-in type spindles (as opposed to belt-driven spindles), which generate less vibration during cutting operations.

Further innovations include six strategically positioned heat sensors that automatically monitor and compensate for any thermal displacement during machining operations. In addition, the spindles feature a reconfigured bearing structure comprising two angular-contact bearings and two taper roller bearings to improve C-axis positional accuracy and spindle runout (less than 6 µm).
The Puma 2600SY Mk II uses high-performance NTN material (as opposed to Turcite) on its box-guideway axes, a move that is said to result in improved and more responsive movement, and reduced wear. Other performance improvements include a revised design of milling turret that incorporates a Curvic coupling piston structure delivering up to 12% additional clamping force; improved durability of the Y-axis carriageway; and a spindle air-purge function that helps prevent chip and coolant ingress.
The machine was exhibited for the first time in the UK at the recent Mills CNC open house, which took place in October.
For further information www.millscnc.co.uk

Mil-Tu-Fit installs DMG Mori CLX450

From its Bristol factory, Mil-Tu-Fit Engineering has been manufacturing precision components for the electronics, oil and gas, defence, construction and medical industries for over 40 years. The company’s machined products are generally under 125 mm diameter with low batch quantities from just one or two parts up to around 100. Commonly machined materials include 303 grade stainless steel and plastics.

“Some of our existing machinery was reaching the end of its useful life and we needed to replace it, and at the same time upgrade our manufacturing capabilities,” says production manager Paul Beattie.
Mil-Tu-Fit evaluated a range of options. The main criteria were a 4th axis, driven tools, the spindle diameter, the number of tool stations in the turret, accuracy and ease of programming.
“Simplicity of programming on the machine was a major consideration as, with small quantities, we need to be able to complete this task quickly and be sure it is right first time,” says Beattie. “I am familiar with the Siemens control on the DMG Mori CLX 450 and had absolute confidence in the system. Programming the Y axis and driven tools can be done easily, while the verification and graphics check ensure a reliable milling and turning toolpath.
“Previously, we would often have to carry out turning and milling operations on multiple machines,” he adds. “We can now combine the operations on the CLX 450, with many parts coming off the machine completed in one hit. As well as manufacturing parts around 20% quicker, we save on handling, we only have to set one machine, and fixtures for different operations have been largely eliminated.”
For further information www.dmgmori.com

Haas lathe boosts stopping power

EBC brakes has been manufacturing high-performance braking components at its Northampton headquarters for nearly 40 years. In addition to the brakes used in various racing classes, the company produces a comprehensive range for road cars, motorbikes and bicycles, both as a standard series built to OEM specifications, and oversized brakes to increase performance.

Central to EBC Brakes’ production are its Haas machines. Machine shop manager Vince Goosey says: “We chose Haas because we love the fact the machines are built in the US. As a company that is built around manufacturing in the UK and US, we want to select machine suppliers that align with our company’s ethos. Investing in Haas – who were selected over a number of competitors – has allowed us to take full control of our manufacturing process by machining all components in-house.”
The Haas DS-30 SSY dual-spindle lathe is used to machine the hubs of two-piece discs for the car side of the business, allowing turning of both sides and the drilling of mounting holes. The two-piece disc, a steel rotor with an aluminium hub, is used predominantly to save weight and improve brake disc performance at the extreme temperatures seen on the track or during fast road driving.
To solve the issue of the rotor fluctuating in size as it heats or cools, EBC uses an SD (square drive) system, allowing the rotor to slide against the hub as it expands or contracts and therefore avoid warping.
For further information www.haas.co.uk

Tornos delivers 200th MultiSwiss

The rise of the Berger Company has seen it become one of the world’s largest enterprises in the field of high-precision turning for the automotive industry, a business built with Tornos turning centres. Berger is constantly investing in state-of-the-art technology to produce turned parts with maximum quality at reasonable cost. Against this backdrop, only a few months after its market launch, the 200th MultiSwiss was delivered to the Berger plant in Ummendorf, Germany.
Berger recently pitched to a leading auto OEM for the global supply of a key component on an advanced direct fuel injection system. The volume amounted to 16 million parts. Herbert Maurer, director of corporate sales, recalls that the requirements were, and still are, fierce. For instance, as the part is installed directly in the combustion chamber, it is made of high-strength material, while the complex geometries have to be machined to a tolerance not exceeding 2 µm.
In the run-up, Berger considered Tornos and other competitive machines to find the appropriate manufacturing strategy. However, the new MultiSwiss soon turned out to be the best option.

“At the moment, it is simply the most precise lathe and, it seemed to be the most appropriate machine to achieve stable processes,” says Maurer.
Instead of experimenting on a sole machine, Berger purchased 10 MultiSwiss machines and has optimised the processes from the very beginning with series production in mind. All 10 machines are now running 24/7.
For further information www.tornos.com

Lathe takes over production of prismatic parts

Looking at the cuboid aluminium components produced for medical diagnostic equipment by subcontractor AES Precision Engineering, one would think they were milled, drilled and tapped on a machining centre rather than a lathe; indeed they used to be, from sawn billet in two separate operations on a pair of three-axis vertical-spindle machines in a total cycle time of 12 minutes.

However, since April this year, they have been machined complete from round bar in one operation on an Italian-built Biglia B565-YS 6-axis turn-mill centre supplied by UK agent Whitehouse Machine Tools. Program run time has more than halved to 5.5 minutes, accuracy is improved and there is no handling between machines or work-in-progress on the shop floor, significantly reducing the cost of production. Only two turning tools can be found in the machine’s 12-station turret, one for facing the bar end and another for parting-off, the remainder are axially and radially driven tools.

Mark Wilson, director of the family-run subcontracting firm, says: “We asked four potential suppliers to offer a turnkey package based on production of the aluminium medical part. Whitehouse demonstrated the best process in terms of quality, capability and cost on a Biglia lathe at its Kenilworth technical centre.”
Production engineer Trevor Orman adds: “The quality of the Italian lathe is high for this class of machine, costing under £200,000 with tooling. Although tolerances on the medical part are fairly open at 0.1 mm, the Biglia repeats to within microns, which means we no longer have to chase tolerance all day as the temperature varies on the shop floor.
“The machine’s accuracy will also be invaluable for the production of more tightly toleranced components, while its rigidity means that tool wear is noticeably lower than on our other lathes,” he concludes.
For further information www.wmtcnc.com