The long-term partnership between US manufacturer, Metalex Manufacturing of Ohio and the Starrag Group has resulted in the installation of the company’s fourth Starrag machine, a large-capacity Droop+Rein T 6-axis portal-type machining centre.

The model T 60 80 DT TT60 HR100 C has X, Y and Z axes of 19,000mm, 9,000mm and 3,000mm, respectively, and to date it is the biggest portal-type machine made in the Droop+Rein T line.

Metalex is a specialist in machining extremely large components of aluminium, stainless steel and titanium, for example, and the capacity of the new machine means that even very large workpieces can be machined in a single setting.

Founded in 1971 Metalex has grown to become one of the leading high-tech manufacturers in the US, employing 130 staff in three factories which produce primarily extra-large components from challenging materials such as titanium, Inconel, nickel aluminium bronze and stainless steel. Customers include large clients in sectors such as aerospace, energy, defence and power generation.

Its new Droop+Rein machine is of rigid construction and is based on hydrostatic operating concepts and so is ideally suited to high-precision/tight tolerance machining of extremely large workpieces with complex geometries.

The machine has a Z axis slide feed milling unit with integrated C-axis and a wide range of milling heads. It includes two rotary tables and turning tool holders (from the Dörries range).

5-axis machining is enabled by two continuous universal fork-type milling heads with up to 2,400 Nm of milling torque. The machine can also be used with motorised milling spindles at high speeds, which can be changed automatically. And, for even more flexible, universal work, there is a 5,500 mm continuous mobile crossbar as the 6th axis (W).

The two tables of 6,000mm by 8,000mm allow one to be used for set-up or inspection outside the work area while the other is being used for machining, and extra-long workpieces can be machined in a coupled tandem formation - which extends the tables to 18,000mm. Each table also has an integrated rotary table of 6,000mm diameter which, thanks to the 111kW main drive, also enables rotary machining of components weighing up to 200 tons. The rotary tables can also be used as a C axis for precision positioning when milling and drilling.

While the 11 machining heads create universal functionality for Metalex, there is also an integrated motorised 18,000rpm spindle for the 5-axis fork type milling head, initially being used for milling large aluminium rings for an aerospace customer. The extra spindle allows Metalex to increase productivity by a huge amount when machining this ring.

The machine has an electronic system for managing the machining heads; an X-Y angular milling head can be ejected to swap with a fork type milling head, for example, so Metalex can effectively keep 30 machining heads to hand.

With over 400 tools served by a robot tool change system, the machine allows the use of tools with CAT 60, CAT 50, Capto-C8, HSK 100 or HSK 63 holders.

Metalex’s latest investment arose after the company was on the hunt for a machine that would satisfy not only its current production needs, but also likely future demands. Although the company already has three Starrag machines, it decided on the Droop+Rein after an intensive benchmarking process. A key factor in the decision was the strong partnership between Metalex and Starrag.

Costing several million dollars, the machine represents the largest single investment in the company's history and Metalex constructed a state-of-the-art production building - with extremely low-vibration foundations weighing 7,000 tons – specifically for it in the Centre for Advanced Large Manufacturing.

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