Super turning center tackles big parts, heavy duty turning
The Johnford ST-40BH is a heavy duty, high precision CNC turning center built for industries such as oil-field, energy, and construction equipment – industries that need large lathes for big parts. Absolute Machine Tools, Inc. offers this massive (25,000 lb) 60 degree slant bed machine, which is available in bed lengths up to 240” and with spindle holes up to 21”. Solid machine construction is key to the ST-40BH’s heavy-duty cutting performance. Built in classic style, the 60 degree slant bed is a torque tube design. The torque tube, or hole cast through the center of the slant bed, provides an extremely rigid bed and excellent heat dissipation. Built tough, with a one piece Meehanite iron design, the turning center takes full advantage of its powerful 35 HP high torque spindle motor and standard four-speed gear box, which delivers high torque at low RPM. An optional 50 HP spindle motor is available for heavy-duty machining on large diameters. The precision spindle structure is mounted using precision double row roller bearings in conjunction with angular contact ball bearings for high rigidity and accuracy. The spindle quill inner and outer linings are precision ground for fit with the spindle, thus ensuring extreme concentricity and accuracy. The machine also features hand scraped, square box ways that provide the rigidity for heavy duty turning. Turcite B applied to all mating sliding surfaces ensures high rapid traverse rates and accurate positioning. In addition, the ST-40BH’s headstock, tailstock, and saddle are all mounted on the same plane at a 60 degree angle to ensure precision and thermal stability. The coolant tank is separate from the machine base to prevent heat transfer from the coolant to the machine casting, which ensures precision and promotes easy clean out and maintenance. To further ensure accuracy and precision, the ballscrews are double nut type and pretensioned to eliminate thermal growth. A 12 station bi-directional turret or optional VDI turret provides 0.5 second indexing as well as coolant through the tool holders. A full C axis with live tools is available for applications requiring milling operations. Fanuc controls are standard for performance and reliability. Other standard features include a hydraulic 15” chuck with soft jaws, a chip conveyor, and a hydraulic, programmable tailstock body and quill. Options include a C axis with live tools. The C axis accuracy is 0.001 degrees. The live tooling used for the C-axis is backed by a 10 HP spindle motor that delivers up to 3,276 RPM.