Ball screws suit electric press brakes

NSK ball screws from the HTF (High Tough) series are helping press brake manufacturers switch from conventional hydraulic drives, to electric drive systems, which offer a number of notable benefits. The ball screws are being delivered to NSK customer Sangalli Servomotori, which is using the units in combination with its brushless servomotors to supply a complete system solution to a global manufacturer of electric press brakes.

When Sangalli Servomotori, located in Italy, was first approached by the press brake manufacturer for its latest range of electric-driven machines, the company knew it had the motor technology, but had to source a suitable supplier of ball screws.
For many years the company had been using NSK bearings in its motor production operations and, impressed with their performance and quality, made an enquiry to NSK about the ball screws in its linear product range.
NSK´s team of experts assessed the application and recommended the company´s HTF series of high-load ball screws. The size of the balls and their special design configuration, along with the material used, are among the principal differentiators in favour of HTF ball screws.
A 63 mm diameter HTF unit was selected to offer a press force of 20 tonnes. Together with a Sangalli servomotor, the ball screw formed the basis for a prototype that was successfully trialled on a customer press brake. In fact, for applications demanding 60 tonnes of press force, an electric system featuring two HFT ball screws has also been developed.
Such has proved the success of the project that NSK has already received its first production orders and Sangalli has started volume production. Importantly, the single-source solution from Sangalli can be applied to the press brakes of any manufacturer, as well as to presses.
For further information www.nskeurope.com

Custom Bystronic press brakes

Bystronic has introduced a newly developed range of press brakes that can be customised to suit a user’s requirements in terms of process speed and flexibility. Available in the UK through the Swiss manufacturer’s Coventry subsidiary, the modular Xpert Pro series comprises three models, plus a variety of optional extras.

First up is the Classic Edition, which is intended for prototype manufacture and job shops producing small batch sizes. Next is the Performance Edition for medium-sized companies that want to produce parts in larger series, while the third model, the Dynamic Edition, is suitable for companies needing even more speed to handle batch sizes of 1000 parts or more. Bystronic says the machines will be among the fastest on the market, with bend speeds up to 20 mm/sec.
Capacity ranges from 100 to 320 tons, enabling sheet up to 15 mm thick to be processed, while bending length is either 3 or 4 m. Companies that require even more flexibility can connect two machines together to bend longer parts.
Due to the variety of configuration options, application possibilities are extensive and an Xpert Pro can be flexibly adapted to new requirements through straightforward retrofitting of optional modules.
Fabricators that have already invested money in bending tools want to reuse them when they purchase a new press brake, but this is not usually possible when changing supplier as there are almost a dozen different tool systems on the market that are incompatible with each other. However, this problem has
been solved by the Xpert Pro range as the machines have been designed so that tool systems from other suppliers
can be used.
For further information www.bystronic.co.uk

Machining and 3D printing work in harmony

Matsuura Machinery will use Southern Manufacturing to show a MX-520 five-axis CNC machining centre and HP Jet Fusion 580 3D colour printer on Stand E260.

The machines will be working in harmony to demonstrate the real-world benefits of current production strategies being supplied by the company to UK manufacturers. Matsuura’s MX-520 will be utilising fixtures produced on the HP Multi-Jet Fusion 4200, demonstrating the time and cost savings generated by printing work-holding systems in hours rather than waiting weeks, sometimes months, for conventional metal solutions to be supplied.
For further information www.matsuura.co.uk

Die-casting shop begins switch to automation

Andover-based MRT Castings, which has long used robotic systems in its aluminium die-casting foundry, has started to introduce automation in the machine shop following the arrival of a Japanese-built Brother Speedio M140X2 five-axis mill-turn cell. The cell is fed automatically with raw material from an interlinked Feedio robotic handling system from the same manufacturer, the first to be installed in the UK. MRT’s turnkey cell was supplied by sole sales and service agent Whitehouse Machine Tools.

One-hit machining is the watchword at the die-casting firm to keep production costs down and remain competitive on world markets, as well as to avoid tolerance build-up and hence maximise component accuracy. A user of Brother 30-taper, four-axis machining centres since the early 1990s, the company now operates 20, half of which are equipped with a pallet changer. In addition, there are three twin-spindle CNC lathes with driven tooling on the shop floor.
MRT’s managing director Phil Rawnson says: “Our pursuit of single set-up production means that we sometimes find ourselves processing parts on our lathes that entail only one-third turning, with the remainder of the cycle taken up by prismatic machining using live tools in the turret. It is an inefficient method of milling and drilling, as the rotational speed and power of the limited number of tools in a lathe are considerably lower than those of the spindle on a machining centre, which also has the benefit of access to more tools.
“So we decided to invest in a mill-turn machine and identified the Brother M140X2 as ideal for our needs,” he adds. “It has a 16,000 rpm, face-and-taper contact spindle and a 22-tool magazine, plus a turning table with a 55 Nm direct-drive motor powering a 2,000 rpm turning table. When not performing a turning function, the C-axis table together with the A-axis trunnion can be employed to position a component in the two rotary axes for 3+2 prismatic machining, which is needed for most of our components.”

To leverage the productivity potential of the M140X2, the plan is for any rotational part that requires a majority of milling and drilling in its cutting cycle, whether machined from a casting, billet or bar, to be assigned to the five-axis machine. The Feedio system, equipped with a six-axis ABB robot, is capable of handling billets up to 80 mm diameter, or aluminium castings up to 120 mm diameter, and delivering them to a hydraulic chuck on the machine table.
A vision system and built-in PC allows the robot to detect where on the upper inlet conveyor of the Feedio the raw material has been placed, so the billets or castings do not have to be aligned on a grid or in a tray. After machining, components are returned to an output conveyor that, to minimise the footprint, is positioned below the first rather than to the side.
Rawnson says: “Until recently, we operated a day shift with a few hours’ overtime in the early morning and evening. The new Brother cell has added to this by allowing us to run lights-out for up to eight hours, depending on component size and cycle times, as well as unattended during the day.”
The first contract to be fulfilled in the automated cell is a family of aluminium bodies for a range of LED light fittings. Prototypes were produced on twin-spindle lathes with live tooling, but as only around 30% of the machining is rotational, it is better suited to production on the M140X2 mill-turn. Cycle time has been almost halved from 15 to 8 minutes, thanks to the higher power of the 16,000 rpm milling spindle and its rapid acceleration and deceleration, tool change in less than one second, up to 30 m/min cutting feed rate, and 50 m/min rapids.
MRT’s production team had been looking for some time at different possibilities for automating its Brother machining centres to increase the efficiency of producing parts in batches of typically 500 to 1,000-off. According to Rawnson, such medium size volumes do not lend themselves readily to automated solutions, which normally require expensive, dedicated, hydraulic clamping fixtures in the machine tool. However, he points out that the M140X2 already has a hydraulic chuck and, therefore, the work-holding function is already in place, so no extra fixtures are needed. It is thus a suitable machine to trial automation in this type of production environment.

To assist in finding the best robotic handling configuration to go with the machine, MRT enlisted the help of the Manufacturing Technology Centre (MTC) in Coventry. After researching the market, its advisers concluded that a conveyor system and a teach-in programmed, vision-enabled, six-axis robot with interchangeable 3D-printed grippers would best suit the types of components produced and machines in use at Andover.
“It was a perfect fit for our needs, which was to acquire a standard, compact, entry-level cell that does not need complex robot programming or workpiece trays, delivered and commissioned by a single-source supplier, in this case Whitehouse Machine Tools,” says Rawnson. “Feedio is suitable for retrofitting to all our Brother machining centres, both non-APC and twin-pallet types, allowing us to reduce operator attendance and maximise production hours during the day. Quality is enhanced, as workpiece loading is more consistent.
“In addition, we are able to extend our single day shift by taking advantage of lights-out running into the evening or even overnight, raising output without increasing our headcount,” he adds. “Importantly, all our operators are supportive of introducing new technology like this.”
He goes on to cite other advantages of the automation system. At present, the LED lighting components are still produced by first completing Op 10 and then reloading them for Op 20. However, they could be produced in one hit if a turnover station was to be introduced. Alternatively, one Feedio could serve two machining centres carrying out both operations simultaneously. There are also possibilities to integrate other functions such as component deburring and washing.
Rawnson concludes: “We see automation as the future for our company. Aluminium billets have been machined so far but the suitability of automatically handling castings is being investigated. We plan to target a wide range of different components for production in the new mill-turn cell, and will be looking in particular at parts where turning content is less than half of the cycle time.”
For further information www.wmtcnc.com

Work holding makes UK debut

From Stand G205, 1st Machine Tool Accessories will show for the first time in the UK the Kitagawa Swift Klamp, a rigid work-holding product that uses the proven HSK tool interface to provide a secure, low-interference, quick-change clamping arrangement which resists bending forces generated during metal cutting.

Developed for five-axis machining applications but equally suited to use on three- and four-axis machines, the system consists of three parts – the clamping head, work holder and workpiece. The head is supplied either as a manually or automatically operated HSK clamp, while the work holder comprises an HSK interface at the base and multiple options at the top for holding the workpiece, including flange clamps and side clamps.
For further information www.1mta.com