High-precision Four-Star Series HRP and HDT sliding gantry milling machine

The HRP and HDT series by Four-Star are compact and medium-format ranges of fixed-table gantry milling machines with sliding columns, designed for precision machining of long workpieces: transmission shafts, linear guideways, structural profiles, extrusion molds, and aerospace components where part length can reach up to 20 meters while maintaining high dimensional accuracy.

Both series share an architecture with columns and beam as a single one-piece casting, and base with table also as a one-piece casting, eliminating intermediate joints and maximizing structural rigidity. The column slider is dimensionally enlarged to reinforce rigidity under lateral loads. X-axis drive uses a ball screw for travels up to 4 m and rack-and-pinion from 5 m onward. The format distinction: the HRP operates with a column spacing of 1,300 mm and table width of 1,000 mm; the HDT covers 1,850 to 2,450 mm between columns with table widths of 1,200 to 1,800 mm.

X-axis travel ranges from 2 to 20 m in both series. Y-axis covers 1,300 mm (HRP) and 1,800 to 2,400 mm (HDT); Z-axis is 800 mm in both. The HRP spindle operates at up to 6,000 rpm and 18.5/22 kW; the HDT maintains the same speed at 22/26 kW. The 24-tool ATC magazine is standard equipment. Positioning accuracy is ±0.015 mm, with repeatability of ±0.003 mm.

An exclusive option on the HRP is the Twin Gates configuration: one gate performs 5-face machining operations while the second simultaneously runs high-speed mold machining on the same table, multiplying productivity across multi-process operations on the same or different workpieces.

The HRP and HDT series target manufacturers of precision elongated workpieces in sectors including machinery manufacturing, aerospace, energy, and extrusion die and mold making.