Italians turn innovation into productivity

Dec. 1, 2003
ALTHOUGH GENERALLY SMALLER than their international competitors, Italian machine tool builders say their strengths are their flexibility and quick response to customer demands. Coupling these with innovations in machine development, equipment integration,

Riello Sistemi's mc 2 production cell combines two independent, single-spindle/ twinspindle machining centers and a fourposition pallet changer (top) to optimize productivity, flexibility, and accuracy.

Mandelli overhauled its Storm 1100 machining center to improve its rigidity and vibration-damping qualities.

Built for the aerospace, automotive, and die/mold industries, the Breton Ultrix 800 mills, turns, and grinds.

The PAMA Speedram 1000 high-speed machining center has the accuracy, spindle speeds, and rapidtraverse rates needed to tackle steel and light alloys.

Buffoli Transfer's Trans-Bar 55+ completely machines parts in one clamping from nonrotating barstock.

ALTHOUGH GENERALLY SMALLER than their international competitors, Italian machine tool builders say their strengths are their flexibility and quick response to customer demands. Coupling these with innovations in machine development, equipment integration, and application-specific solutions lets the Italians complete on a global scale. This was in evidence at the recent EMO 2003, held in Milan, Italy, where companies like Riello Sistemi, Mandelli, Breton, Pama, and Buffoli Transfer exhibited high-tech machining centers, boring machines, and transfer systems.

For instance, Riello Sistemi SpA, Minerbe, Italy, debuted the mc2, a flexible production cell that reportedly optimizes productivity, flexibility, and accuracy. It boasts two independent single-spindle/ twinspindle machining centers and a four-position pallet changer that simultaneously rotates the pallet and any relevant guarding. This configuration permits automated loading/unloading.

To reduce machine weight and maximize static and dynamic rigidity, Riello engineers employed a monolithic base with web-like ribs. In addition, they designed the machine's traveling support, which carries the rotary table and the X and Y axes, to optimize the weight/ dynamic-rigidity ratio for high accuracy and acceleration.

The mc 2 tackles medium-tohighvolume production of steel, cast iron, and aluminum parts with dimensions that fit within a 19.69-in. cube. It has four 24-kW spindles delivering 12,000 rpm, and each has its own toolchanger and 20-position tool magazine. Shops can use each spindle as a single spindle for critical applications and as a twin spindle on other operations.

When the mc 2 runs as a singlespindle system, its chip-to-chip time is less than 1 sec. This is possible because one spindle cuts while the other changes the tool, accelerates, and moves into position for the next operation.

Another Gruppo Riello company, Mandelli Sistemi SpA, Piacenza, Italy, unveiled its overhauled Storm 1100 machining center. The machine's claim to fame is a modular build that accommodates end-user specifications such as integrated material-handling systems. Mandelli can also equip the machine with a U 8000 head that provides a 30% increase in rpm compared with the previous U 6000 version. The Storm 1100 is also available with a 6,000, 10,000, or 15,000-rpm horizontal H head.

In addition to these features, the machine sports performance improvements that boost acceleration and deliver speeds of 131.23 ft/min. For example, linear axes have guides fitted with a thermo-stabilized device that monitors thermal variations and dampens vibration.

For shops requiring high-speed systems capable of milling, turning, and grinding, the Ultrix 800 from Breton, SpA, Treviso, Italy, may fit the bill. Breton engineered it for vertical and horizontal operations — from hard roughing to accurate finishing on materials ranging from light alloys to steel — on one machine.

Ultrix 800s come in two versions: the Basic, with four axes, and the 5-axis RT. The RT version also features a direct-drive milling/turning rotary-tilting table.

The machining center includes several accuracy-enhancing features, including a mobile-bridge gantry that ensures rigidity and maximizes the working area. Also, a thermalstabilization system compensates for thermal expansion of the machine's structural components. And the machine's metalquartz structure dampens vibrations, further ensuring accuracy.

Another noteworthy introduction at EMO was the Speedram 1000 floor-type horizontal boring and milling machine for machining medium and large workpieces. According to builder PAMA SpA of Rovereto, Italy, it engineered the system for both modularity and reliability. Its X-axis column has a 158-in. stroke that extends with the addition of 40-in. modular units. PAMA also offers three boring spindles — 5, 6, and 6.3 in., with a maximum rotational speed of 4,000 rpm.

The machine features hydrostatic guideways, a geometriccompensation system, and a completely closed ram assembly. Toolchangers of different capacities and workpiece-checking devices offer progressive levels of automation, making the Speedram well suited for everything from single-workpiece machining to large-batch production.

Brescia, Italy-based Buffoli Transfer SpA unveiled its Trans-Bar 55+ horizontal-axis transfer machine at EMO. Fed by nonrotating barstock, the machine finishes even the most complex parts from both directions and transversely, in one clamping. On average, the machine generates cycle times of 2 to 10 sec, which is roughly 50% shorter than a multispindle automatic, according to the company.

The nonrotating-bar process ensures the machine's working tolerances are held to tight process specifications. In addition, it guarantees the concentricity of internal and external operations. And with up to 40 tools, the Trans-Bar 55+ precisely machines parts, front and back, as well as complete external and internal surfaces and transverse features in seconds.

The modular transfer system can be equipped with CNC profiling heads for precision machining using CNC-guided interpolation; 3-axis multiprocess modules for drilling and threading operations and interpolated milling; and accessories for rolling, marking, knurling, broaching, or milling.

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