The Mitsui Seiki J350G jig grinder offers a combination of application flexibility, accuracy, and operator-friendly operation. The machine’s grinding infeed stroke is the largest available among competing machines, with a U-axis range of -3 to +50 mm relative to the spindle center. This provides the flexibility to grind small and large-diameter holes, as well as multiple features, using a single wheel in a continuous, automatic mode.
To maximize accuracy, the X- and Y-axes of J350G are hand scraped and incorporate needle roller bearings. The machine bed consists of a thick, highly rigid casting supported by three-level points, assuring consistent perpendicularity and parallelism. Built-in, custom-designed Heidenhain scales contribute to +/- 0.0007 mm accuracy on the X, Y and Z-axes.
Table longitudinal travel (X axis) is 500 mm, transverse travel (Y-axis) is 300 mm, and quill travel (Z-axis) is 100 mm. Maximum distance from the table surface to the grinding spindle nose is 450mm. The machine’s work surface is 700 mm x 350 mm and permissible table load is 300kg.
Table and saddle maximum rapid feed rates are 2,000 mm/min and grinding feed rates are variable from 0.1mm/min to 2,000 mm/min. The standard high-frequency spindle motor operates from 9,000 rpm to 45,000 rpm. A variety of spindle motor options include an air-turbine motor with 75,000 rpm capability.
The machine’s 3m2 (2,220 x 2,610 mm) footprint is 50% smaller than that of the previous model, maximizing floor space efficiency. A standard total enclosure machine cover permits easy operator access while fully addressing safety and environmental concerns.
The J350G’s Fanuc 31i-B control has a 15" touch panel LCD screen and is preloaded with G-MAPS conversational-style programming software. The control also permits easy manual programming via graphic icons, data entry, or conventional methods.