High Quality Surfaces with Fidia Milling Centres
The mould makers of Farmingtons Automotive rely on a Fidia gantry machine to achieve a perfect surface for trim parts of car interiors. This new milling centre GTF3514/MA2200 comes in addition to milling machines used for roughing, considerably cutting production time and substantially improving quality of machined surfaces.
The requirements for surface quality of plastic parts in the automotive sector demand sophistication. A big challenge mould suppliers face is constantly keeping up with growing standards while producing fast and economical products. “Neither the price nor the delivery time allow for much space for quality improvement”, says Jörg Ulbricht, head of cutting processes and mould making at Farmingtons Automotive in Georgsmarienhütte, Germany. “Our Company makes moulds for a wide spectrum of plastic parts – although there are also technical parts, most of them, however, are trim parts that require an absolutely perfect surface.”
Farmingtons Automotive GmbH is part of the Welp Group and is as a complete supplier, offering from one source engineering, prototype construction, tool making up to series manufacturing. The business activities in tool making include:
- feasibility studies and tool related consulting;
- simulation of moulding and shrinkage and deformation calculation;
- product optimizing and mould engineering;
- CNC programming;
- tool production up to testing, calibration and optimizing;
- tool repair and maintenance.
Another strategic area is special vehicle manufacturing. Based on the standards vehicles Farmingtons automotive experts develop and produce custom designed vehicles.
The requirements for surface quality of plastic parts in the automotive sector demand sophistication.
Broad range of tools
Farmingtons Automotive is a complete supplier – the options ranging from components’ development to mould making and the in-house plastic coating for components delivered to the OEMs conveyor belts ready to be mounted. They produce a wide variety of parts from lighting over interior equipment to technical in-mould parts. The tools for the company’s in-mould production are made in Georgsmarienhütte as well. “The major part of our moulds, however, go to the in-mould productions of our customers”, Ulricht explains. “Most of the mould we produce for the Tier-1-companies of the automobile sector, for car as well as for utility vehicle builders”. Dimensions range from 600 x 600 mm with a weight of 4 to 5 tons up to 2600 x 1600 x 1000 mm with a weight of up to 40 tons. All common tool steels are machined as tempered materials up to 55HRC, which are not causing any particular difficulties in the workshop. “For that we dispose of a highly productive machinery”, Ulbricht reports. “For large parts we used to mill with a FOG-Type machine of Droop+Rein, well advanced in years and still reliable and productive – but for moulds for trim parts, however, it was no longer accurate enough”.
“Within few weeks of mounting and installation, the machine was ready and the
geometry calibrated. The very competent Fidia engineers did an excellent job.”
Looking for a machine for finishing?
Most of the plastic parts relevant for Farmingtons Automotive require an accuracy of ca. 5 hundredth of mm – this means one hundredth at the mould. “For roughing the Droop+Rein still is a good choice”, explains the head of mould making. “But particularly when it comes to surfaces where high accuracy is crucial, we had to take a lot of efforts to meet the requirements for our work.” Especially considering that time and costs for manual finishing are no longer acceptable today. In order to get the proper support for the Droop+Rein, the head of the workshop worked together with the machine operators to draw up a plan of action. They needed a machine for pre finishing and finishing, but at the same time suitable for heavier machining. “We wanted to achieve a better quality of surfaces together with a shorter milling time”, Ulbricht summarizes the core requirements. “In addition we wanted to put into practise the proportion of machining with reduced staff and at the same time considerably faster processing – and this with a view on the total process chain. Because optimising process steps isolated from each other is the wrong approach – possibly such proceeding on the whole has negative impacts on the total process.”
After thorough comparison of the concepts of various machine tool builders, the mould makers decided in favour of a Gantry machine of the Italian machine tool builder Fidia, a GTF3514/MA2200. “We were lucky, the machine Fidia exhibited at EMO in Milano last year was available with a short notice,” Ulbricht remembers. “But it was still in a stadium in which it could have been modified according to our own requirements and ideas. Within few weeks of mounting and installation, the machine was ready and the geometry calibrated. The very competent Fidia engineers did an excellent job.”
In their clear decision for the machine, the Farmingtons team found reassurance in knowing that quite a few of their customers had Fidia machines installed in their workshops. “Admittedly this gives you a reassuring and good feeling”, Ulbricht confirms. “We already knew Fidia as the producer of the CNC installed at our Droop+Rein,” the mould maker explains. “We highly estimate the Fidia controls as very powerful and at the same time easy to operate”.
“In our view the new C40 control is considerably faster and better than any other products available on the market.”
Powerful Control
The CNC Fidia C40 is believed to be the “flagship” of the numerical controls in the marketplace today. “In our view the new C40 control is considerably faster and better than any other products available on the market”, the head of mould making believes. “Thanks to the double processor architecture, external programs can run on the CNC while the machine is working. So we also can, without any problem, program at the machine in parallel with primary processing time. Or – but this is here still a future development – measure directly via the CNC with measuring probe and 3D Form Inspect of M&H.”
Functional machine
The new machining centre offers axis strokes in X/Y/Z of 3500 x 2200 x 1400 mm. The machine is built in mono block construction, which means it does not need a foundation. In case of a modified plant layout, the machine can also be moved and easily relocated. The operator can check and compensate geometric errors on the milling head by using Fidia’s Head Measuring System (HMS). This machine is designed for 5 axes simultaneous machining with a spindle rotation of 24.000 min -1 and offers 88 Nm with 55 kW. The velocity can be doubled from 30 m/min to 60 m/min to speed up work performance.
“The Fidia GTF3514/MA2200 is the optimal machine for us”, resumes pleased Jörg Ulbricht.
Better use of the working area
“The HSK 63 tool holder is shifted 75mm from the centre of the head resulting in a working area extended by a total of 150 mm,” Ulbricht calculates, “you only have to use the head accordingly”. The tool changer holds 42 tools up to a length of 300 mm. The mould makers in Farmingtons Automotive rely on Haimer tool holder devices. Ulbricht: “Especially in 5 axes simultaneous machining, but also in 3+2 axes operations, we can thus also use long tools. This brings a lot of advantages.” Cooling can be done with liquid coolant, minimal volume lubrication or by compressed air through spindle centre. This machine has three chip conveyors, two located next to the machine table and one in front of the machine table. The machine is also suitable for high volume chip removal.
Speed up milling time
The machine is very rigid due to its mono block structure. Its double rack and pinion drives system fully compensate backlash, ensuring high accuracy. “The Fidia GTF3514/MA2200 is the optimal machine for us”, resumes pleased Jörg Ulbricht. “We achieve our goal – higher quality at shorter processing time – to the full extent. And we could reduce considerably especially the reworking.”
Single-piece structure
The GTFM has a U-shaped cast iron monolithic structure. This solution saves time and cost at machine mounting, installation, along with possible repositioning in the plant. At the same time, it allows a modular structure that simplifies design and manufacturing of different size machines.
