MAG's T-Rex spindle recently demonstrated triple the metal removal rates over previous spindle designs for an aerospace customer machining Carpenter 465 hardened to 50-52 Rc. A 75 mm dia Harvi inserted endmill with five flutes and 13 inserts per flute was used in the demonstration. The cutting parameters were 100 mm axial depth of cut, 24 mm radial depth of cut, and 0.5 mm/rev feedrate.
"This cut produced an excellent surface finish with no sign of chatter and virtually no vibration, using only one-third of the available spindle power," reported Pete Beyer, MAG's product development manager. "The spindle power is so great that it easily handled the full Y-axis thrust of the demonstration machine, which can be equipped with higher torque axis motors to produce even higher metal removal rates."
MAG's high torque T-Rex spindle, available on 4-axis HMC 1250/1600 machines, can deliver up to 2,600 Nm torque into a cut to produce extreme metal removal rates on large workpieces of hard materials, such as titanium, Inconel and Carpenter 465.
Developed for the machining needs of aerospace, energy and heavy equipment manufacturers, the T-Rex spindle is engineered with 130 mm ID bearings to handle the 42.3 kN cutting thrust capability of the HMC 1250/1600 series horizontal machining centres. The T-Rex spindle is currently available on 4-axis machines, configured with 80 kW drive and two speed ranges up to 5,000 rpm.
The HMC 1250/1600 features an X-bed, Z-bed and column of cast ductile iron, with pallets up to 1,600 by 2,000 mm, headstock and rotary table housings in grey cast iron. The 360,000-position full-contouring rotary table provides a rigid work platform, while a rugged worm gear drive with clamp securely holds axis position. Rotary table positioning accuracy is 10 arc-sec, repeatable to 5 arc-sec.
The HMC series comes as standard with linear scale feedback in X, Y and Z axes, providing 8 micron positioning accuracy and 5 micron repeatability. Heavy duty hardened and ground roller guideways enable a rapid traverse rate of up to 40 m/min with high acc/dec rates.
Eight spindle options include: 6,000 and 8,000 rpm/46 kW tilt spindles with +90/-120º A-axis travel; a 10,000 rpm/46 kW spindle; high speed 24,000 rpm spindle; T-Rex high torque 2,600 Nm/80 kW spindle and two live spindles (110 or 130 mm diameter).
The high torque T Rex spindle is specially engineered for hard metal cutting, while the live spindles extend W-axis reach by up to 800 mm, enabling deep cavity milling to high precision with shorter, more rigid tools. MAG's Z-axis thermal compensation system, standard on the live spindle, dynamically offsets spindle growth to maintain correct axial position regardless of spindle temperature.