Okuma VTM-100

The Okuma VTM-100 is a turn-mill machine for parts up to 1,000 mm (39.37 in) in diameter and 840 mm (33.07 in) long, with a turning spindle that runs from 13 to 1,250 rpm and a separate milling spindle. Okuma lists 30/22 kW (40/30 hp) for each of the two spindles. X travel is 650 mm (25.59 in) and Z travel is 840 mm (33.07 in).

That top speed is high for the diameter. The rim of a 1,000 mm part never needs 1,250 rpm, but small bores, hubs and bosses near the centre do, and large flanges and housings usually carry exactly those features. A range that starts at 13 rpm and ends at 1,250 rpm lets one setup face the full diameter and then finish a small bore at a proper cutting speed.

For milled features the table lists a C axis with a rapid rate of 20 min⁻¹, so the workpiece can be indexed or rotated under the milling spindle for bolt circles, cross holes and flats. Linear rapid traverse is 16 m/min. Neither rate is fast, but on parts of this size cutting time dominates the cycle.

The X travel shapes what the milling spindle can reach. At 650 mm (25.59 in) it covers the radius of the largest part and a little more, so features on the far side of centre are brought round by the C axis instead of being reached by traversing across the face. The VTM-80YB is laid out the other way: a smaller 800 mm (31.50 in) turning diameter with 1,120 mm (44.09 in) of X and 1,135 mm (44.69 in) of Z. Okuma's table for the VTM-100 gives no Y travel, table load or tool magazine figure, so confirm those if the work depends on them.