Okuma VTM-80YB

The Okuma VTM-80YB is a turn-mill machine whose travels are larger than its turning diameter: 1,120 mm (44.09 in) of X, 710 mm (27.95 in) of Y and 1,135 mm (44.69 in) of Z around a table that turns parts up to 800 mm (31.50 in). The table drive is 30/22 kW (40/30 hp) with 800 Nm (590 ft-lb) of torque and a speed range of 8–800 rpm.

The Y axis is the reason to pick this model. With 710 mm of true Y travel the milling spindle cuts flats, keyways, slots and off-centre holes with straight-line moves, where a machine without Y has to combine X with table rotation. And because X is longer than the part is wide, a tool can cross the whole face in one pass. The milling spindle takes CAT 40 (BT 40) tooling.

On the turning side, 800 Nm (590 ft-lb) at the table is the figure that limits depth of cut at large diameters, where the cutting force works on a long lever arm. The 8 rpm bottom speed suits full-diameter facing. The 800 rpm top speed is adequate for mid-size diameters but restricts cutting speed on small bores. A C axis is listed with a rapid rate of 20 min⁻¹ for indexing and positioning.

Z travel and turning length are 1,135 mm (44.69 in), long for the diameter. The VTM-100 takes a larger 1,000 mm (39.37 in) diameter but has 650 mm (25.59 in) of X and 840 mm (33.07 in) of Z, while the VTM-1200YB steps up to 1,200 mm (49.21 in) with 1,270 mm (50 in) of X. Okuma's table gives the milling taper but no milling power, milling speed, table load or tool count, so get those in the quotation.