The Johnford HT-30-2SD is a heavy-duty, high precision CNC turning center built for industries that need the productivity afforded by a two-spindle turning center. Absolute Machine Tools Inc. offers this 45-degree slant bed machine, which offers a 30-hp high-torque, double-wound main spindle as well as a 15-hp double-wound subspindle.
The 16,500-lb turning center is cast from Meehanite iron, and the 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 excellent heat dissipation, the company says.
Square boxways provide the rigidity for heavy-duty turning, the company says. Hand-scraped Turcite-B applied to all mating sliding surfaces ensures high rapid traverse rates and accurate positioning. To ensure precision and thermal stability, the headstock, tailstock and saddle are all mounted on the same plane at a 45-degree angle. 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, according to the company. To further ensure accuracy and precision, the ballscrews are double-nut type and pretensioned to eliminate thermal growth.
The turning center has 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 used for the C axis is backed by a 10-hp spindle motor that delivers as much as 3,276 rpm. The C-axis accuracy is 0.001 degrees. 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 bidirectional servo turrets or optional VDI turrets provide 0.3-second indexing as well as coolant through the toolholders. Fanuc CNC controls are standard as well as a complete coolant system, a chip conveyor and a hydraulic 10" main chuck and 8" rear chuck.
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