With its bed and portal angled forward at 20 degrees for driving high jerk loadings free from vibration, the g-Mill 550 BAZ presented by Liechti is said to promote free chip flow and rigidity, with uninterrupted view of workpiece and tool. According to the company, users can experience a 30-percent increase in productivity when machining flow profiles because of the dynamics of the machine. Also available is a double-spindle version, the g-Mill 550 Twin, which has the capability to practically double output capacity.
The double-spindle version accommodates manufacturers requiring capacity for blisks and impellers up to 320 mm diameter and turbine blades up to 550 mm long. The machine handles twice as many components in the same time as the single-spindle version.
While the single-spindle version achieves 7,000 hours of production annually, the twin version attains 14,000 hours. With an additional investment of 20 percent and an increase in production of almost 100 percent, the price per spindle, and therefore per workpiece, is reduced by 40 percent, says the company.
The single-spindle g-Mill features a second spindle that can be retrofitted, and it incorporates the same basic design as the dual-spindle version. The portal, in which the XY cross-slide moves, has a cross-slide that has been extended in the vertical direction to provide space for the second spindle. This reduces the Y path from 600 mm to 330 mm, and rotary components such as blisks and impellers may have a maximum diameter of 320 mm instead of 550 mm in the single-spindle machine. The workpiece length of 550 mm (for blades) remains unchanged.
The spindles of both models have an output of 22 kW each, developing 183 Nm and rotating as high as 15 000 min-1. The tool magazine for a double-spindle BAZ features a standard chain magazine. Fifty positions can be installed several times, so a maximum of 144 tools are available.
Both versions operate on the workpiece side with a swivel-changer and a loading/unloading station, requiring one operator for component handling during shift operation. However, the twin version can be optionally supplied with a 20-chain magazine for ten double workpieces (alternatively there is also a 50-oval magazine with portal robot).