Traveling-Column, Horizontal Boring Mills Increase Accuracy

Fives Giddings & Lewis introduces a new line of traveling-column, horizontal boring mills (HBMs) said to offer high accuracy and cutting capacity, moving the column in the Z-axis and the tables in the X-axis. Engineered for flat-floor installation, the first models of the machine are configured with a 10,000-kg (22,000 lbs) capacity, 1,250 × 1,400 mm (49.2" × 55.1") contouring rotary table. Optional 1,400 × 1,800 mm (55.1" × 70.9") tables are also available. The RT 130 and RT 155 versions feature 130 or 155 mm (5.1" or 6.1") diameter gear-driven spindles available with power as high as 45 kW (60 hp) and torque of 3,380 Nm (2,493 foot-pounds).

The machines feature an electronically counterbalanced Y-axis headstock with side-hung headstock design for improved visibility and access for the operator. The spindle snout reaches over the table for rigid cutting without extension and, with spindle travel, extends well beyond center. In addition, the spindle can reach below table top to probe for location on the table or a particular feature. The zero-backlash rotary table is powered by two independent motors and pinion drives that are tensioned against each other to compensate for any lost motion.

Heavy-duty linear ways utilize roller bearing carriages that ride on hardened and ground guideways. This rigid, low-friction system is designed to support high loads and fast rapid traverse speeds. Linear ways are said to facilitate better true positioning and contouring accuracy by eliminating stick-slip and thermal growth. They also require less lubrication, thus reducing coolant contamination, says the company. Standard XYZ travels are 2,000 × 1,500 × 1,600 mm (78.7" × 59.1" × 63") with W-axis spindle travel of 750 mm (29.5"). An integral table-mounted pan helps contain chips and coolant.