Put to the test

Today, the company employs 210 members of staff and enjoys a turnover of €30 million. It specialises in the manufacture of high-added value parts, making good use of its expertise in tool manufacturing and complex mechatronic systems.

As many as 70 staff across two eight-hour shifts, work in the project department. Since 2005, the focus on the design and manufacture of titanium, aluminium, Inconel and refractory steel parts and sub-assemblies, has facilitated strong growth. This of course requires ongoing investment in technology; on average, €2 million a year has been spent on high quality machines and tools as purchasing manager, Mikael Helloco explains.

“The first goal was to find gantry vertical milling machines capable of machining 80% of engine parts and structures,” he explains, “and we had to find the right balance between efficiency and precision to ensure excellent quality without breaking the bank.

"For the manufacture of complex parts produced from hard and light metals with a high stock removal rate, our machines have to offer high levels of rigidity during roughing operations and good dynamics and precision during finishing.”

After selecting a shortlist of suppliers with equipment potentially meeting the above criteria – large-sized machining centres that combine power, torque, high speed and high axis dynamics, it was decided to put the machines through their paces through a series of technical titanium machining tests in the presence of Sermati engineers.

These tests showed that Spanish manufacturer Correa scored well above the required levels. The machines were required to perform a 25mm chatter-free stroke using an end mill with the ram fully extended. Correa’s Fox machining centre managed to reach an impressive 60 mm.

"During the test, we even surprised ourselves,” states Juan Martín, sales manager of the Correa Group. “The 3-axis UAD machining head in the Fox machining centre develops 52kW of power with a torque of 1,300nm and 6,000rpm. This is further complemented with a 5-axis UGV milling head rotating at 12,000rpm generating 35kW with 190Nm. Available for automatic loading straight from the adjacent magazine, the two heads fulfil this complementary role to ensure both roughing with major chip formation on the most difficult materials, and finishing of complex shapes with the highest possible precision, are achievable.”

The Fox machining centre combines both cutting-edge technology with 70 years of Correa know-how in the design, manufacture and distribution of milling machines with more than 1,000 gantry milling centres sold in the last 25 years.

Based on a finite element analysis, Fox machines combine mechanically welded structural and cast iron elements with a mixed guiding system on cooled, large-diameter linear guides leading to a sound balance between stiffness, damping capacity, dynamic movements and precision. In addition to a thermo-symmetrical design, a thermal compensation system and cooling of essential mechanical elements such as the milling head, considerably reduce expansion.

Sermati has selected the two milling heads that best meet its requirements from the extensive choice available. The range of mechanical spindles reaches 6,000rpm and 1,500Nm in S1, with increments of 0.02º by mechanically locking the crowns. The HF spindles offered for 5-axis milling heads reach speeds of up to 24,000 rpm.

The change of milling heads is automatic, using the magazine located at the base of the gantry. Thanks to the wide range of available accessories, Correa Anayak can offer turning-machining solutions for these types of centres. For Sermati, a high-pressure lubrication unit was installed on the two Fox centres, providing a lubrication pressure of 38 bar pressure through the spindle centre and 14 bar for external lubrication.

"As soon as we ordered the Fox machining centres, we advised our customers of the capacity available,” Mr Helloco advises, “and by the time installation was complete, we already had enough work for two eight-hour shifts.”

In the UK, sales and support of Correa Anayak machines is handled by Chorley-based DTS (UK). Formed in 2005 by Gary Sanderson and Andrew Bailey, the company is sole has sole distribution agreements established for Nicholas Correa and Johnford machining centres

DTS (UK) www.dtsuk.co.uk