Compact Automatic Jig Grinder

The Mitsui Seiki (Franklin Lakes, NJ) J350G jig grinder combines flexibility, accuracy, and operator-friendly operation. The machine’s infeed stroke is the largest available among competing machines, with a U-axis range of -3 mm 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 are hand-scraped and incorporate needle roller bearings. The machine bed’s thick, highly rigid casting supported by three level points ensures consistent perpendicularity and parallelism. 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 table surface to grinding spindle nose is 450 mm. Work surface is 700 mm x 350 mm and permissible table load is 300 kg.

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. Spindle motor options include an air-turbine motor with 75,000 rpm capability.

The machine’s footprint of 2,220 mm x 2,610 mm is 50% smaller than the previous model’s, maximizing floor space efficiency. The total-enclosure cover permits easy operator access while addressing safety and environmental concerns.

The Fanuc 31i-B control has a 15-in 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.

Mitsui Seiki USA, 563 Commerce St., Franklin Lakes, NJ 07417, 201-337-1300, www.mitsuiseiki.com.