Sharp 30120TC-F

The Sharp 30120TC-F is where the 3000 series changes character. With 118 in (3,000 mm) between centers on a 177 in (4,500 mm) bed it weighs 15,400 lb (6,985 kg), about half as much again as the 78.75 in model, the 3080TC-F, at 10,120 lb (4,590 kg).

That jump tells a buyer something the capacity table does not: the long-bed machines carry far more iron, and with it more foundation, more rigging and a 18.70 ft installation length. Width and height do not change from the short machines at 6.56 ft and 5.91 ft.

A ten-foot shaft makes its own demands on a lathe with a single carriage. Z travel is 118.1 in (3,000 mm), driven by a 1.96 in (50 mm) ball screw and a 4 hp Z-axis servo motor, the same screw and motor Sharp lists for the shortest bed. Cutting feed is 118.11 ipm (3,000 mm/min). Sharp's inch and metric rapid figures disagree, so no rapid rate is shown here; ask for it, because traverse time over this length is part of every cycle.

Swing over the bed is 29.92 in (760 mm) and the bore 6.7 in (170 mm), with the usual 20 hp (14.91 kW) geared head running 10-1,000 rpm. For work this long the standard steady rest (3"- 8") is a starting point. The hydraulic tailstock with foot pedal and the follow up rests on the options list deserve a look before the order is placed.