Mitsui Seiki
Mitsui Seiki PJ 303X five-axis machining center

High Precision, Versatility in Five-Axis Machining

June 8, 2022
IMTS visitors will see a new model in action for smaller workpieces, offering speed, accuracy, and functionality in a compact workspace.

MITSUI SEIKI’s PJ 303X five-axis machining center will be on display at IMTS 2022 – Booth 338700. The PJ 303X maximizes precision and versatility in processing workpieces up to 230 mm tall and 280 mm in diameter (9 x 11 in.), and weighing up to 20 kg (44 lbs.)  Typical applications include lens molds, medical products, EDM electrodes, and fuel cell components, and a range of other critical parts.

In contrast to Mitsui Seiki machines for machining of large, critical components, the PJ303X is designed to machine smaller parts accurately. Its X-, Y-, and Z-axis travels are 300, 325, and 200 mm (11.8, 12.8, 7.9 in.) respectively. The A-axis rotation is +40˚ to -100˚, and the C-axis rotates a full 360˚.

High-speed linear motors move the X-, Y- and Z-axes, while the rotary axes employ direct-drive motors. Rapid traverse speed for the X-, Y-, and Z-axes is 20 m/min (66 ft/min).

A 50,000-rpm, HSK-E25 taper spindle offers high-speed machining capability, and an automatic tool changer stores up to 24 tools as large as 40 mm (1.57 in.) in diameter and 100 mm (3.9 in.) long.

The attachment surfaces of the ways as well as other critical areas of the PJ 303X are hand-scraped, to maximize precision. Advanced spindle thermal displacement technology is standard, including a symmetrical gantry column structure that accommodates thermal deformation fluctuations and a thermal compensation mechanism for the machine spindle/head.

Operator-friendly features include a 15-in. display with touch panel capability that can be moved to the most convenient position relative to the work envelope. The control is Fanuc’s new F31i-B5 with the i-H Pro control panel. The machine’s double-stage rotary door provides wide access for visibility and set-up.

As for floorspace, the PJ 303X occupies 1,755 x 2,375 x 2,890 mm (5.75 x 7.79 x 9,48 ft; W x L x H) and weighs approximately 5,500 kg (12,000 lbs.)

“The compact PJ 303X machining center provides high precision, speed, and versatility for the processing of an important range of part sizes across a wide variety of applications,” according to Mitsui Seiki USA chief operating officer Bill Malanche.

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