The stiffness of a Giddings and Lewis HMC 1600, combined with the machine's 42.3 kN (9,500 lb) cutting thrust, provided an ideal platform for the high-torque T-Rex spindle to demonstrate the industry's highest titanium metal removal rate (MRR) for a single spindle at 33.1 in3/min. The above video depicts a recent test for an aerospace customer on titanium 6Al-4V utilizing a Harvi indexable-insert end mill with 76.2 mm (three inch) tool diameter. The tool was driven at 245 rpm with an axial depth of cut at 76.2 mm (three inches) and a radial depth of cut at 25.4 mm (one inch), with a feed rate of 1.14 mm/rev (0.044 in/rev). "This cut produced an excellent surface finish with no sign of chatter and virtually no vibration," said Pete Beyer, director of product strategy and development at Fives Giddings Lewis. "The power of this spindle is so great that it easily handled the full Y-axis thrust of the machine, which can be equipped with higher torque axis motors to produce even higher metal removal rates.” The T-Rex spindle, available on four-axis HMC 1250/1600 machines, can deliver up to 2600 Nm (1,918 lb ft) torque to produce extreme metal removal rates on large workpieces of hard to machine materials, such as titanium, Inconel and Carpenter 465. The HMC 1250/1600 can also be provided with a five-axis high-torque tilt spindle with continuous torque of 1161 Nm (856 lb ft). Many other spindle options are available for the HMC series as well, including quill spindles and high speed units up to 24,000 rpm. The T-Rex spindle provides 60 kW (80.5 hp) continuous power. Developed for the machining needs of aerospace, energy and heavy equipment manufacturers, the T-Rex spindle is engineered with 130 mm (5.1 inch) ID bearings to handle the 42.3 kN (9,500 lb) cutting thrust capability of the HMC 1250/1600 series horizontal machining centers. Meeting industry needs for tighter part tolerances and accuracies, the HMC Series comes standard with linear scale feedback in X, Y and Z axes, providing eight micron (0.0003 inch) positioning accuracy and five micron (0.0002 inch) repeatability per ISO 230-2. Heavy-duty hardened and ground roller guideways enable a rapid traverse rate of up to 35 m/min (1378 inches/min) with high acceleration and deceleration rates, double the load capacity and nearly 10 times the wear life of ball-type guideways.