VMC Offers Jig Milling/Boring Accuracy with Machining Center Productivity

Mitsui Seiki USA Inc. continues to advance U.S. critical parts manufacturing capabilities with the launch of the PJ812 CNC vertical machining center (VMC). Its jig borer feature aids in more complete machining of critical medical, optical, electric vehicle, mold and die and aerospace parts including precision boring, milling, drilling and tapping. 

The PJ812 offers travels X: 1,200 mm, Y: 800 mm and Z: 500 mm. Max work size is 1,200 mm x 800 mm. Table load accommodates 1,500 kg. The VMC also provides positioning accuracy and repeatability of +/- 1µm. A thermal compensation system employs sensors on the machine faceplate and inside the spindle to minimize the effects of temperature changes on part accuracy and cut temperature-generated displacement by 60%, the company says. The system also is said to reduce Z-axis thermal growth and deflection by 30%. Cooling systems for slideway lubrication and ball screw cores stabilize axis feed precision.

Mechanical design features that maximize machine rigidity and accuracy include hardened and ground tool steel box slideways as well as contact elements that enhance acceleration, reduce stick-slip and allow for feed accuracy of 0.1 µm. Another proprietary engineering detail is said to improve the static rigidity of the Z-axis to more than six times that of conventional Z-axis arrangements. The machine features a full enclosure and various coolant system options.