CMS milling of high speed machining of composite materials

International machinery is a Guipuzcoan company specializing in systems engineering of manufacturing for the aeronautical sector, automotive and auxiliary companies. It develops turnkey solutions with processes integrated to the machining of composites, resins, brasses, light alloys, steels. One of its main represented is CMS.

CBS, Italian company specialized in the manufacture of components for the aerospace sectors, defense and automotive (racing and high-end sports cars), has recently consolidated the Alliance with CMS through the acquisition of its third model Antares PX5 CNC machine.

Founded in 1989 and certified according to ISO 9001: 2000 since 1998, CBS has won a good reputation as a supplier, highly qualified for parts of composite material, which has among its clients highly prestigious brands, such as Aermacchi, Agusta, Recaro Aircraft Seatings, Ferrari, Lamborghini, Maserati, Momo, Oto Melara.

The growth of this company has also increased its collaboration with the Enterprise CMS, which began with the supply of 5 axes from 1999 machining centers, and gradually gained a strategic role in the business of CBS. The director of CBS, Luigi Peroni, briefly tells the story of your company: "90 years our production consisted mainly in composite panels and components in 3D hand - finished to aerospace - getting them from moulds supplied by customers." Entering the market of the automotive industry meant a huge increase in the volumes of production and an increase in the quality requirements. We therefore had to move from a manual production to an industrial. The help of CMS 5-axis CNC machines allowed us to achieve higher productivity and a consistent high quality. With the passage of time the demand increased and the production required a more comprehensive control over the production process, a better and more flexible system that would allow us to react more quickly to the needs of the market. "So we decided to start the production of moulds and models ourselves."

It was at this point when CBS were able to appreciate and take advantage of the potential of the products and services of CMS; through machines CMS is now working models of resin or aluminium, templates and parts in composite material. For example, the production process for the manufacture of a panel of a car of high performance carbon fiber is composed of:

• The acquisition of CAD geometries of the client.
• CAM processing and generation of tool paths.
• Production of models (male or female) of resin epoxy in CNC machine.
• The production of molds for parts of fiber carbon, mooring in the model, and autoclave polymerization.
• Milling of the templates used to support and hold the pieces with braces during the finishing operations.
• Healed parts of carbon fibre in the autoclave.
• Finishing of the CNC machine parts: recanteado, drilling, etc.

Thanks to the dynamic characteristics of the machines CMS can achieve the precision, the repetitibilidad and the cutting speed necessary to obtain a competitive production costs. The investment made in the machine pays off quickly.

This is the biggest advantage on the milling machines and machining of metal centers. Traditional metal cutting machines losers, in price/performance ratio, when it comes to machining of aluminum or composite materials.

In addition, special solutions provided by CMS, to contain and remove the dust of the machining, the total safety of the operator and the ease of working in a category of machine made to measure for the machining of non-ferrous metals, are very different from the traditional machine tools for metals.

Luigi Peroni reaches the following conclusion: "Thanks to the Alliance with CMS acquired a very competitive machine which, together with our experience over the years and our professionalism, has enabled us to reach important goals." "Since 1999--when we bought the first machining center - CBS turnover has increased approximately 400% and our ability to competitiveness drives us to achieve more ambitious goals".

Crosby Composites of United Kingdom has invested and recently installed a CMS model 3626 Ares brand CNC machining centre. Mr Crosby founded his company for 25 years and has spent all his working life in the motor sports industry. He began his career as an engineer in March, when the use of composites in racing cars was introduced for the first time. "It was obvious that it was a very big opportunity so I created my own company," he recalls. "We started with very basic methods of 'lay-up', and soon to develop the means and knowledge to work with 'pre-preg' and cured in an autoclave".

Mr Crosby entered the modeling 3D and mecanizó with him over 8 years. Before that, I had thought that the systems were too expensive but this machining CNC and CAD/CAM quickly became the normal way of doing things. "Using this type of technology is the only practical way to machine make repetitions with the level of precision that we need," he adds. "The market of the F1 in general requires a maximum of sixteen parts running." "Unless you can be very efficient, it is difficult to justify the cost of producing the entire machining process".

Speaking of the newly installed machine and the positive impact it is having on business, Crosby said that "it is important that as a company we provide best available technology." "This is exactly what we have done with this new capability offered by CMS, we know will provide us them a higher precision technology for manufacture of the model to expand our competitiveness and secondly, a high capacity of recanteado and machining of carbon fiber with which we can obtain very competitive costs, so critical in today's market".

CMS UK conducted a well studied planning of the project to ensure that all parts of the project were delivered and installed in the correct sequence and at the right time to meet the tight deadlines requested by Crosby and issued by the motor sports industry.

The installed equipment is the machining center CMS model Ares 3626 of 5-axis, with a 3,600 mm, an axis X axis and 2,600 and a z-axis of 1,200 mm, equipped with a large work of 3,120 x 2.020 mm table. This system allows to work in tandem or in a single table. The automatic doors ensure that the operator will be completely protected from the machining area and a sophisticated vacuum gripper system provides a very effective mooring of the piece, a great benefit to this type of work. The two comprehensive axes of rotation with a power of 12kW, 24,000 rpm tools HSK spindle and automatic tool changer of 8 stations, guaranteeing exceptional cutting capacity.

One particular advantage of the CMS 5-axis machine head is the only mechanism for fixation of axis Rotary, giving greater rigidity in the mode 3 + 2 machining and 3 axes. As a result of the great experience of CMS in the industry, the machine is equipped with effective protection against the entry of dust from the areas electrical and mechanical carbon fiber, as well as a Bell of efficient extraction that turns with the movements of the axes in the head.

Tool breakage monitoring is carried out using a laser to ensure the accuracy of machining and avoid collisions. A catheter radiofrequency full package and provides the necessary functionality for the positioning of the workpiece and the inspection.

In addition to increase accuracy with this approach, another big advantage is that all the machining and inspection cannot be completed on the CMS machine in a single mooring and tooling. According to Mr Crosby, it is impossible to maintain the necessary tolerances when moves the piece of the equipment, while using multiple tools or fixation devices and control would take much more time.

The first group of seventeen components produced by this method is supplied to one of the teams in F1 and was mounted in the car without having to repeat the work.

It was the first time in the history of the Crosby company that had happened to the first set of composite parts to be fully approved for mounting.

"Since then have used in the company this verification system as much as us to have been possible", said Crosby. "This system ensures that we can find errors before the parts to reach our customers." In these six months since we started with this approach, we have only had one rejected piece and it was because of a smaller hole. "Will continue using this technology to make things better and more accurately," concludes Mr Crosby.