Multitasking Turning Center Offers Twin Spindles

The Johnford HT-30-2SD high precision, CNC turning center is built for industries that require the productivity of a two-spindle turning center. This 45-degree slant-bed machine features a 30-hp, double-wound main spindle that delivers high torque at low rpms. There is also a 15-hp, double-wound subspindle.

The 16,500-lb turning center is cast in Meehanite. The true 45-degree slant-bed is a torque tube design. The torque tube, or hole cast through the center of the slant bed, provides a rigid bed and enables heat dissipation, the company says.

Square box ways provide the rigidity for heavy-duty turning. Hand-scraped Turcite-B is applied to all mating sliding surfaces to ensure high rapid traverse rates and accurate positioning. Also, the headstock, tailstock and saddle are all mounted on the same plane at a 45-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 is said to promote easy cleanout and maintenance. To further ensure accuracy and precision, the double-nut type ballscrews are pretensioned to eliminate thermal growth.

The center features a high precision spindle that incorporates 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 to ensure extreme concentricity and accuracy.

A full C axis with live tools is optional for milling operations. The live tooling is backed by a 10-hp spindle motor that can turn at a rate of 3,276 rpm. The C-axis accuracy is 0.001 degree. The subspindle can also be equipped with an optional C axis with live tools. An optional Y axis provides vertical turret movement for complex off-center milling functions.

Twin 12-station, bi-directional servoturrets or optional VDI turrets provide 0.3-second indexing as well as coolant through the tool holders. Fanuc CNCs are standard. Other standard features include a complete coolant system, a chip conveyor and a hydraulic 10" main chuck and 8" rear chuck.