Absolute Machine Tools offers the Johnford ST-40BH, a heavy-duty CNC turning center for the oil-field, energy, construction and other industries that need large lathes for big parts. The 60-degree slant-bed machine is available in bed lengths ranging to 240" and spindle holes as large as 21". According to the company, the machine's torque tube — a hole cast through the center of the slant bed — improves rigidity and heat dissipation.
With a one-piece Meehanite iron design, the turning center features a 35-hp, high-torque spindle motor and a standard four-speed gearbox, which delivers high torque at low rpm, the company says. An optional 50-hp spindle motor is available for machining large diameters. The spindle structure is mounted with double-row roller bearings in conjunction with angular contact ball bearings. The spindle quill inner and outer linings are precision ground to fit with the spindle, which ensures concentricity and accuracy, the company says.
Also contributing to rigidity are hand-scraped, square box ways. Turcite B is applied to all mating sliding surfaces for high rapid traverse rates and accurate positioning, and the headstock, tailstock and saddle are mounted on the same plane to ensure precision and thermal stability. A 12-station, bi-directional turret or optional VDI turret provides 0.5-second indexing and has coolant-through capability. Other standard features include a hydraulic 15" chuck with soft jaws, a chip conveyor and a hydraulic, programmable tailstock body and quill. A C axis with live tools and accuracy of 0.001 degree is optional.