Outstanding milling

[article by Edoardo Oldrati, original source: "Tecnologie Meccaniche" Magazine, June 2017]

The German mould maker, WFT Werkzeug- und Frästechnik, has invested in Breton milling solutions. Specifically, in the recent Flymill HD for machining superalloy, steel and aluminium parts with complex three-dimensional shapes.

Founded in 1997, but the heir of an entrepreneurial history that started in 1919, WFT Werkzeug- und Frästechnik is a German company that manufactures matrices and moulds for punching, foaming and compression moulding of all kinds for the automotive, aerospace, medical and renewable energy industries. 

“State-of-the-art technology and many years of know-how”, explain Frank Elzener and Stefan Lühr, managing director and owner of the company respectively, “allow us to provide our customers with everything they need for each process phase, from design and manufacture to assembly and testing, giving them a single source procurement service”.

In the Coppengrave plant in Lower Saxony, more than 50 employees use modern production systems to machine blanks. The CNC machines have up to a maximum of 5 programmable axes and can machine workpieces up to 8 metres long and weighing up to 46 tonnes.

One of the strengths of WFT is precisely this advanced fleet of machines, which takes up four halls with an overall surface area of 3 thousand square metres. For the past three years, WFT has relied on machines supplied by Breton. Currently the company's plant houses a Breton Matrix 1000, with axis travel of 2200 x 2500 x 1000 mm, and a new Flymill HD with head change and an axis travel of 8000 x 3500 x 1300 mm.

Flymill HD in action

HIGH MILLING PERFORMANCE

A company like WFT must be able to rely on milling machines that can combine high material removal capacity with high accuracy. Precisely for this reason, a partnership was started with the Italian manufacturer Breton, which has supplied two machines in recent years.
The most recent one is the high-speed, high-performance milling machine with 5 continuous interpolated axes, the Flymill HD. It is ideal for machining superalloy, steel and aluminium parts with complex three-dimensional shapes that must be made accurately.

A sample worked by WFT with the Breton Flymill 1300 milling machine

To ensure high performance, the Flymill is equipped with sturdy shoulders made using the exclusive Metalquartz® technology, which provides high structural rigidity and a high degree of vibration damping to guarantee improved surface finish and increased cutting tool life.

The large work table size, the strength of the structure and the large operating travels make this high-speed milling machine suitable for use in a single work area or in pendulum mode, with a milling speed of up to 40 m/min for the linear axes, reaching up to 60 m/min in rapid mode. The bi-rotary heads (with continuous C-axis rotation, A-axis rotation up to 135°, power of 85 kW and rotation speeds of up to 100 rpm) allow the machine to rapidly perform even the most complex machining, working simultaneously in all three dimensions with very simple programming. In fact, considering that the A-axis can rotate up to 135°, it is easy to perform difficult undercuts without repositioning the workpiece. 

The machine model installed at the German company has an axis travel of 8000 x 3500 x 1300 mm. There are electrospindles for the Flymill HD heads that can guarantee high performance through their bilateral fork structure made of cast iron, which gives them structural strength and vibration damping ability. The Breton Flymill is equipped with the Tornado HD head, which can take a 75 kW (S1), 14,000 rpm spindle for rough machining and finishing.
Also noteworthy is the compact structure that meets the increasingly widespread demand for small-footprint systems. 

Furthermore, the Breton machine previously installed in WFT, a Matrix 1000 with an axis travel of 2200 x 2500 x 1000 mm, features high machining speed and high material removal rate.

It is a high-speed, high-precision machining centre for milling parts with complex three-dimensional shapes, ideal for applications in the aerospace, automotive, mould making and design industries. In fact, thanks to the speed of its linear axes, which can reach 60 m/min, and its Direct Drive head with a continuous C-axis rotation speed of 100 rpm, the Matrix can perform uncommon high-precision and dynamic machining of complex profiles with 5 continuous axis.

Matrix 1000 Dynamic

The bi-rotary continuous head with direct drive can be positioned at any angle within its operating range, thanks to powerful hydraulic brakes. This makes it possible to use spindles with continuous powers of up to 40 kW and 28,000 rpm, giving the machine a considerable material removal capacity.
It is also worth noting that it can easily handle high-speed machining and milling of both light alloys and other special alloys that are often used in the aerospace industry.

The completely enclosed structure with mechanisms at the top of the machine offer maximum operator safety with maximum machining reliability and precision. Its machining quality and precision are also achieved through the thermo-symmetry of the structure and the a thermal stabilisation system in the Z-axis lead screws and bearings and the axis drives, which keeps the temperature of these parts aligned with that of the machine structure during operation. 

This stabilisation system makes the machine practically immune to deformation caused by the thermal dilatation of the structure that is induced by continuous daily use for high-speed machining. Sophisticated finite element method (FEM) dimensioning integrated with global dynamic simulation has made it possible to obtain strong structural elements that combine stable geometric precision with dynamic high acceleration of the operating units.

THE KEY TO SUCCESS

WFT manufactures prototype moulds, pilot moulds and production moulds for a wide range of plastic machining technologies. Depending on the geometry of the workpiece, the number of components and the customer's needs, WFT can offer the optimal mould concept from both the technical and economic points of view, providing its customers with recognised know-how as well as intelligent and highly technological solutions. 

In addition to its versatility, another element behind the success of WFT is its ability to follow the whole implementation cycle of moulds and customised machines, from design to production. “Our personnel create the three-dimensional model of the component to be made on CAD/CAM workstations. The design department is connected with customers around the world, allowing them to see the data on line and to perfect the design through direct consultation”.

The target industries for the moulds made by the German company impose high quality standards.

“Quality is our watchword”, confirms the technical department, “and many years of experience and the constant training given to our engineers and experts guarantee the highest quality combined with reduced production times. To ensure excellent quality, every aspect of all moulds and machines is tested before being delivered to the customer. Moreover, visual inspection is an effective method, but it is not enough to meet the current requirements imposed by the manufacturers of components for the automotive and aerospace industry. 

For this reason, we reply on complete control systems and we manufacture measurement devices and test equipment from aluminium, steel or light material, to guarantee accurate measurement of every product. Here, the distinctive feature lies in making the measurement: in fact, the test and measuring devices provide assessment, documentation and display. We can also build custom test devices to meet customer requirements”.

The ability to innovate is also essential, not only by investing in a fleet of state-of-the-art machines, as we have seen, but also by developing new technologies. An example of this approach is the innovative joint technology for plastic products that WFT uses in its plant. 

To make products such as trims for doors or bumpers, dashboards or fuel tanks, packaging components or medical items, plastic components are applied to various objects. In these cases, WFT uses latest generation joining technology to integrate metal elements into the plastic, fold laminated materials or securely fasten thermoplastics by welding or riveting.

For more information please write to mail@breton.it.

Thank you for the attention and best regards.

Bye-bye

Sergio Prior

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breton flymill, flymill hd, Matrix 1000 Dynamic, WFT

A suite for 5 axes

BRETON, MANUFACTURER OF 5-AXIS MACHINING CENTERS, PROMOTES THE INNOVATIVE BRETONGEAR SUITE TECHNOLOGY, A VERTICAL SOFTWARE PACKAGE FOR THE DESIGN AND MANUFACTURE OF GEARS. 

Cogwheel for wind turbine

The world engineering market is constantly evolving, and the gears sector follows the same trend. Modern gear manufacturers require machines that are accurate, versatile and user friendly to compete in a market in which production lot sizes are shrinking, and in which production requirements can change abruptly.

                                                                      

Traditional processes (with gear cutting machines) have some significant limitations, concerning product design, prototyping and manufacturing phases. They remain competitive only for high production volumes, but are unsuitable for producing prototypes and small lots (typical of large gears from 500 mm to 3,500 mm in size) as the tools are very expensive, have long procurement lead times and the geometric tooth finishing process is normally very long. It is in this niche that the commercial 5-axis milling machine shows its effectiveness.

Thanks to a partnership with KISSsoft - world leader in developing computation software for the mechanical engineering industry - together with decades of experience in manufacturing numerically controlled machine tools, Breton has developed BretonGear Suite, a vertical software package (BretonGear CAD and BretonGear CAM) developed in synergy with the machine tool for designing and manufacturing gears.

Starting from the very high accuracy of the surfaces generated in KISSsoft, the designer now has a freedom in defining the tooth geometries never seen before with traditional methods. With the BretonGear CAD application (using the CAD Rhinoceros engine) it is possible, in bevel helical teeth for example, to machine the relief groove at the tooth root in the same way as it is created using hobbing cutters with protuberance on cylindrical teeth. Or making topological changes to distort the surface itself, moving the contact area between mating teeth, which is key in reverse engineering.

Double-helical pinion for excavator

Once the gear geometry has been defined, you can pass to the BretonGear CAM environment, available in both the PC and the touch screen version installed on-board the machine, which through an integrated approach can guide the operator in selecting tools and defining cutting strategies. Today, in version 2.1 with an even more intuitive interface and with a tool library that now, for the first time, includes side cutters as well as the more generic cylindrical, toric and spherical end cutters.

This innovation introduces a further degree of versatility to the cutting methods available, resulting in considerable time savings when machining gear wheels with straight or helical teeth. Side cutters can be of two types: shaped (where the tool defines the shape of the tooth), or the more common variety, straight sided, where the machine creates the shape of the tooth by envelopment. All of this can be viewed by the operator through real-time simulations, offering him complete control over the cutting strategies, thereby eliminating the need for the dedicated CAM office required in other specialised sectors such as aerospace.

BretonCAM accompanies the operator throughout the cutting process with dedicated applications even after the gear has been case-hardened. Careful management of the excess metal and a best fit function that determines the piece’s ideal position within the machine with a measuring cycle before and after hardening, limits the distortion that follows heat treatments. In addition, the T.A.O. (Tooth Accuracy Optimizer) algorithm calculates the tooth cutting order to distribute the tool wear and improve the accuracy of the tooth. These technical solutions are the result of research and development in the field alongside experts in the gear sector.

So far we have only talked of 5-axis gear cutting using commercial milling machines, which is competitive compared to the traditional bevel gear cutting methods for more than 5 modules and diameters greater than 300 mm. 

For smaller numbers of modules and diameters, face milling strategies are more effective. The basic difference between the two lies in the fact that, in the face milling method, the profile of the tooth is created by the synergy between the machine’s movements and dedicated shape of the cutter. 

Breton Ultrix with “face milling”

Traditional CAM software is not able to simulate this delicate interaction between the machine and the cutter. For this reason, Breton has undertaken a collaboration with HyGEARS, developer of a powerful gear design and analysis software.
Through an interface designed together with Breton, HyGEARS replicates the movements of a conventional gear cutting machine. 
The result? A considerable reduction in cutting times. A case study conducted on the same bevel gear cut using both methods found execution times four times shorted (25 mins against 100 mins),  ideal for medium sized lots.

Of course, developments in the world of 5-axis gear cutting are not just limited to software but also hardware. Breton has optimised its range of machines with an emphasis on monoblock models ULTRIX and XCEEDER, now equipped with trunnion tables with a central hole which allows machining pinions up to a maximum length of 850mm and shank diameter of 220mm (until now a limit for this kind of machine), and FLYMILL and MAXIMA gantry models that can machine gears with diameters up to 3500mm.

For INFO and request about Breton machine for gear production, write now to mail@breton.it. 

Well, that’s all for today. 

Bye-bye

Sergio Prior

(Software KISSsoft, Rhinoceros and HyGEARS are trade mark ®)

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5-axis gear cutting, 5-AXIS MACHINING CENTERS, breton flymill, breton maxima, breton Ultrix, breton xceeder, BretonGear

Breton FLYMILL- Vertical machining centre for milling carbon fiber, steel, titanium, resin and aluminium.

A solution to meet all your needs: from carbon fiber to titanium

High-performance and precision machining centre for milling complex three-dimensional workpieces which require accurate machining and 5 continuous axis interpolation. FLYMILL is the ideal solution for any application in the aerospace, automotive, gear and mould sectors since it can machine a variety of materials, from composite to aluminium, steel and titanium.

Wide choice of configurations for customized performances

Various solutions for the best machine configuration to satisfy any need:

- Standard version with one work area

- Two work areas for pendulum machining

- Model with pallet change system or with integrated milling table.

Easy access and clear view

Excellent accessibility and a clear view of the work area thanks to the machine gantry structure with moving bridge and wide frontal/back doors.

High precision, dynamics and flexibility with 5 continuous axis, high-speed machining

In order to always ensure high performances, FLYMILL is provided with heavy-structured shoulders manufactured using the ground-breaking Metalquartz technology that ensures a very high structural rigidity and vibration damping, which guarantees a better surface finish and a longer service life of the cutting tools.

Three high-performance Direct Drive heads

Electrospindles always offer the best machining performance thanks to the cast-iron fork designed head which offers structural rigidity and efficient vibration damping. 

FLYMILL can be equipped with the Tornado HD head capable of housing a 75 kW (in S1 duty) spindle with 14.000 rpm in order to perform roughing and finishing operations.

High-Speed, Dynamics and Precision

The carriage and beam travel on well dimensioned, double recirculating roller guides ensuring machining precision and stability. All axes are moved by systems with double preloaded pinion and rack. 
Maximum precision is achieved thanks to the position detection through optical scales. Axes are controlled by digital drives with latest generation brushless servomotors.

Wide choice of electrospindles

FLYMILL machining centre can be supplied with a wide range of electrospindles depending on the type of machining required. Machining precision is always guaranteed by the spindle thermal stabilizing system and a software designed to compensate natural thermal expansions of the Electrospindle when machining conditions change.

M 51/28
Electrospindle featuring a power of 40 kW, continuous torque of 51 Nm in S1 duty and 28.000 rpm: the ideal choice for customers requiring high-speed machining on either steel or light alloys, from rough-machining up to precision finishing.

M 100/18
Electrospindle featuring a power of 40 kW, continuous torque of 100 Nm in S1 duty and 18.000 rpm: smartly performing any machining operation on either steel or light alloys, from rough-machining up to precision finishing.

M 300/14
Electrospindle featuring a power of 48 kW, continuous torque of 300 Nm in S1 duty and 14.000 rpm: amazingly efElectrospindle featuring a power of 48 kW, continuous torque of 300 Nm in S1 duty and 14.000 rpm: amazingly efficient when machining either steel or super alloys, from rough-machining up to precision finishing.

Simple and reliable tool magazines

According to the various models, wheel-type or chain-type tool magazines with fast manipulator to reduce tool changing times are available. 
Installed outside the work area and therefore free of dirt, these tool magazines ensure the greatest reliability over the time. 
They can be equipped with an automatic coding system containing tool data and chip reading.

Top-roof bellows and dust extraction

Ideal for machining composite materials and aluminium, FLYMILL can be fitted with an efficient dust extraction system which is installed on the spindle nose and top-roof bellows that enclose the machine thus isolating the work area from the immediate surroundings. 
Different models of dust extraction and fume intake systems are available to satisfy any specific customers' needs.

The ideal tool cooling system

Depending on the need of machining, the coolant system can use external or through the spindle coolant with fixed or variable internal pressure (up to 70 bar), or incorporate a spray mist system, or simply use compressed air.

Monitoring and in-process inspections

FLYMILL can be supplied with a laser/touch tool presetter and a radio controlled probe to acquire the size and coordinates of the workpiece and position it more easily.

For INFO and request write now to mail@breton.it. 
Well, that’s all for today. 
Bye-bye
Sergio Prior

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5 continuous axis, aerospace, automotive, breton flymill, carbon fiber, gear, machining centre milling, mould, titanium

Fast, for complex moulds

Mondialstampi needed to produce large, high quality moulds with complex profile shapes as quickly as possible; the answer was the Breton Flymill 1000 machining centre, and considering the mould improvements achieved, it was exactly the right choice. 

When we move around the home or the garden we rarely pay much attention to the objects around us because we see them every day and know them well. If we did stop to look at them closely we'd soon realize that most of them are made of plastic. The same conclusion would be reached also if we were to examine our cars, both inside and out.   What's fascinating about this is the complexity of some of these parts: wafer thin in sophisticated shapes. A lot of work goes into the design of parts like these, not just the design of the part itself but in particular the mould into which the plastic will be injected. 

For Mondialstampi  a company that has become highly successful in the industry since its incorporation in Vicenza in 1990, solving problems in the plastic injection-moulding process is their daily bread.

For your home and car

“Our company is entirely dedicated to the production of injection moulds,” says Mondialstampi owner Giorgio Cortese. “We specialize in medium-large moulds mainly for household goods, such as under-bed storage units, boxes and other storage units of various shapes and sizes. We also produce moulds for automotive parts, such as bumpers, wings and interior trim, and last but not least, we make moulds for various garden articles such as outdoor storage cupboards, plant containers, composters and ornamental objects. In collaboration with third parties we also touch on many other minor sectors, but the three I have mentioned are the primary drivers of our business.”                  

“We've always worked very intensively in Italy, although market conditions have led us increasingly to look towards exports,” continues Diego Bertollo, Head of Mondialstampi's Engineering Department “Today, our production is roughly half and half: 50% for the domestic market, and the rest for export, mainly to other EU countries. We also export to Russia, Canada, and South America and, on a smaller scale, to several other countries.”
Today the company has a workforce of around 50, of whom 10 in the Engineering Department, where mould design activities are conducted using CAD/CAM systems. We have 20 technicians in the workshop and another 15 people engaged in mould assembly and testing procedures.

A well-defined structure

The Engineering Department has a very delicate job: the moulds are produced in a co-engineering process together with the customer since this approach has proven to be the optimal way to produce any given component, but it means we must also adapt each and every solution to comply with the technology and plant available to the customer.                               

Once the 3D model of the part has been created, meetings are held to eliminate any possible misunderstandings between the mould designer and the customer in terms of the solutions to adopt. When the project has been approved, the 3D model is used to produce the actual mould. First, the guidelines of the mould are defined, and then the engineering department uses CAD software to produce the definitive 3D model. The next stage involves the transition to CAM, the implemented features of which mean it can automatically recognize a large number of the work processes defined in CAD. 

“At this point the production department takes over, but first the steel ordered by the engineering department for the mould is checked before it goes into production,” explains Cortese. “The initial roughing operations are now performed on some of the machine tools at our disposal. As the production cycle proceeds, the plates are moved to the finishing machines to create angled holes and for other special machining processes.”

Once machining chips have been removed, the plates are transferred to the assembly area, where operators check conformity of the parts before proceeding with assembly. “To aid our personnel and minimize the risk of errors we've equipped the various assembly areas with CAD stations,” explains Bertollo. “Thanks to this solution, our personnel can actually see how the various parts fit together, leaving no room for doubt.” Once finished, the mould is tested in a mould testing press to check for any problems and see if any minor corrections are needed. Final testing is performed in the presence of the client, and if all requirements are met, the go-ahead for production can be given.

There's no dedicated unit in charge of quality control, which is instead performed directly on the machine using probes that can detect even the smallest imperfection so that the part can be reworked without having to remove it from the machine. Mould quality is therefore guaranteed by the two Breton machining centres installed in our factory, which are used for mould finishing operations.

Reliability pays

“In the household articles industry in particular we work with very thin parts where even one-hundredth of a millimetre can make a difference”,  continues Bertollo – “We need machining centres that can guarantee the highest quality and that’s why we chose the Breton Flymill 1000.”

“Producing large, complex moulds, reducing milling times, improving surface quality and increasing working life.  These were the requirements we wanted to address by purchasing a new 5-axes machining centre,” says Cortese. “Ten years ago we bought a Breton Matrix 800, and we've never had any problems with the plant or the after-sales service. That's why we decided to look at the possibility of purchasing another Breton machine.”

The company finally opted for a Flymill 1000, a 5-axes machining centre that differs from the Matrix in its working range, structure and spindle power: longitudinal travel of the new machine in fact is up to 8 meters and it is equipped with a 5-axes head with Direct Drive motors. In any case, both solutions were designed specifically to meet the requirements of high-speed machining in the mould  making industry, so they are the natural choice for these applications. 

In particular, the Matrix is a travelling cross beam gantry type machining centre with a fully enclosed structure and drive assemblies located at the top of the machine, making it extremely safe for operators and guaranteeing the highest level of reliability and precision during machining. The high quality and precision of the machining work are also a result of the thermal symmetry of the structure, while a thermal stabilization system for the Z axis ball nuts and bearings and axis drives keeps the temperature of these parts the same as the machine structure.

Both the Matrix and the Flymill are equipped as standard with a continuous rotation Direct Drive twist head with C axis continuous control, and the spindle can be used with a continuous power output of up to 40 kW at 18,000/28,000 rpm giving the machine considerable chip removal capacity. 
Mondialstampi actually purchased the Flymill with a more powerful head to use the new machining centre not only for finishing, like the Matrix, but also for prefinishing operations.

In addition, the new machine is much faster than the original one: 60 m/min for the X and Y axes and 100 rpm for the C axis compared to the 40 m/min and 19 rpm of the Matrix. This performance derives from the choice to equip the machine with guideways mounted on racks rather than on recirculating ball screws, giving the system a more rigid structure and allowing it to reach higher speeds.  
Furthermore, the Flymill is ideal for machining complex profiles thanks to the generous working range of the A axis, which is from –105° to +120° thus making it possible to machine difficult undercuts without having to reposition the workpiece.

“Both units are extremely high-tech solutions and that's why they're entrusted to highly specialized technicians dedicated exclusively to running the machine”. Cortese concludes – “Our aim is to exploit the Flymill to its maximum potential in order to transform our investment into a technological advantage that will help us consolidate our market position.”

For more INFO about Matrix  800 and Flymill 1000 write to mail@breton.it.

Thanks to Mondialstampi

Thanks to TM - Tecnologie Meccaniche, by Davide Davò. 
By-by
Sergio Prior

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aerospace machining, automotive machining centre, breton flymill, breton machining centre, breton matrix, mondialstampi