Okuma VT1000EX

The Okuma VT1000EX is a large-diameter turning lathe for work up to 1,000 mm (39.37 in) across and 1,000 mm (39.37 in) long, driven by a 55/45 kW (75/60 hp) spindle that runs from 10 to 800 rpm. X travel is 650 mm (25.59 in) and Z travel is 1000 mm (39.37 in), so the envelope is as deep as it is wide.

The speed range says what the machine is for. At a 1,000 mm diameter the rim of the part reaches a normal cutting speed at a few hundred rpm, so the 800 rpm ceiling only restricts small bores and hubs near the centre. The 10 rpm floor matters more: it lets a full-diameter face or an interrupted cut in a casting run at a controlled surface speed. With 55/45 kW behind it, the spindle is sized for roughing forgings and castings, and sustained cuts should be planned around the lower figure of the pair.

Among Okuma's machines of this diameter, the VTM-100 also turns 1,000 mm (39.37 in) on the same 650 mm (25.59 in) of X, but it lists 30/22 kW (40/30 hp) and 840 mm (33.07 in) of Z travel and turning length. The VT1000EX is the one to look at when the job is heavy turning that needs the larger motor and the full 1,000 mm of length.

A few details need attention before ordering. The chuck in Okuma's table is a 254 mm (10 in) hydraulic unit, small against a 1,000 mm (39.37 in) turning diameter, so rings and discs near the limit need jaws, a larger chuck or a fixture agreed in the quotation. Rapid traverse is 16 m/min (52.49 fpm) on both X and Z, which is slow but has little effect on long cuts in heavy parts. The table gives no table load, turret or machine weight figure, so those have to be requested.