Four-Star series FDW mobile gantry double-column milling machine

The FDW series by Four-Star is a range of double-column machining centers with moving cross-rail, incorporating the W axis for vertical cross-rail travel between 1,000 and 2,000 mm. This extends the working height range beyond the fixed cross-rail configuration of the FD series.

The structure combines fixed columns with an extended base, a box-in-box cast-iron cross-rail, and a cross-rail positioning system using dual synchronous servo control with hydraulic clamping (Patent M511389). A triangular support design keeps the center of gravity within the columns, and cross-rail slope is maintained at 0.01/1,000. Each column incorporates 3 linear guideways and 1 positioning rail to ensure precision in vertical cross-rail movement at any position along the W travel range.

X-axis travel ranges from 2,200 to 6,000 mm; Y-axis from 1,800 to 5,400 mm; Z-axis from 800 to 1,500 mm; and W-axis from 1,000 to 2,000 mm. Column spacing covers 1,850 to 5,450 mm, with table loads up to 26 tons. The RAM spindle head has a standard cross-section of 450×400 mm, with an optional 550×550 mm version for larger models.

The BBT-50 spindle operates at up to 6,000 rpm and 22/26 kW (continuous/30 min), driven by a two-stage H/L planetary gearbox. The 32-tool ATC magazine with random tool selection is standard equipment. Positioning accuracy is ±0.015 mm, with repeatability of ±0.003 mm and cross-rail slope of 0.01/1,000.

The standard CNC is FANUC 0iMF. Optional configurations include 5-face and 5-axis simultaneous milling heads, automatic head changer (AHC), embedded CNC rotary table (diameter 800–2,000 mm, indexed or simultaneous to 0.001°), and 650 mm Y-travel extension for automatic 5-face machining. Mitsubishi, Siemens, and Heidenhain controllers are available as alternatives.

The FDW series targets manufacturers machining complex geometries or workpieces with significant height variation, where vertical cross-rail adjustment optimizes spindle reach without reconfiguring the fixture setup.