Mills CNC launches enhanced Mark II series of Doosan DNMs

The DNM 400, DNM 500 and DNM 650 models are equipped with 12,000 rpm direct-drive (in-line) spindle technology and a more rigidly-designed and built headstock which generates less noise and vibration than their belt-driven DNM predecessors. As a consequence, the Mark II machines deliver better surface finishes during fine machining operations. The improved spindle technology also provides faster acceleration/deceleration rates that translate into reduced cycle times. (The Mark IIs take just 2.16 sec to reach their maximum machining speed of 12,000 rpm – a reduction of 55% over earlier models.) The Mark II DNM 400 and 500 machines feature a 18 kW / 117 Nm torque spindle, and the DNM 650 a 18.5 kW / 140 Nm spindle, resulting in improved cutting performance especially during heavy-duty operations and in high volumetric stock removal. The machines benefit from oil-cooled spindle heads and a thermal compensation package as standard. Thermal error in Y and Z-axis directions caused by growth in spindle temperature is compensated by internal algorithm based on spindle rpm and run-time characteristics. Performance of the Mark II DNM machines is further enhanced by their roller-type guideways (as opposed to ball guideways found on predecessor DNM machines). The increased rigidity of the roller guide technology supports long-term accuracy and provides a more reliable and stable machining process. Other features of the Mark II series include improved operator visibility of the working area and the introduction of a swivelling operating console; better workpiece loading and unloading capabilities including a top cover opening for crane access; and a Doosan-developed easy-to-use and easy-to-understand software package for fast set-ups and more effective operation.