Fourth-Axis Verticals

RoboDrill T-21EL DDR 700 V size vertical machining centers, from Methods Machine Tools Inc. (www.methodsmachine.com), are available with either 10,000-rpm or 24,000-rpm spindles, and employ direct-drive indexing systems for extremely highprecision positioning and fast cutting speeds in their fourth axes.

DDR high-speed fourth axes dramatically reduce part cycle times by eliminating the positioning delays of traditional rotary tables and enable machining at the high speeds of the other three machine axes. The system’s gear-free, zero-backlash linear motors unclamp, rotate 180 degrees and re-clamp in about 0.4 seconds at table-rotation speeds of 150 rpm. It’s a 140-mm unit with a maximum torque of 192 ft-lb and load capacity of 220 lb, and a 40-mm through hole allows for pneumatic or hydraulic fixture actuation.