Compact Miyano BNJ-Series 3 turn-mill centre for harder materials

Requiring a floor space of just 2.7 by 1.5 m, the Miyano BNJ-42SY3 is the first machine from the fixed head turn-mill specialist to feature Citizen software which significantly improves the optimisation of cycle times through combined and overlapped movements. The BNJ has a main 11 kW spindle giving 6,000 rpm and a 5.5 kW, 5,000 rpm sub spindle - both serviced by an all-driven main 12 station and a six station back-working turret. The introduction of two concave sections in the backworking turret and the ability to install an off-centre collet in the rear spindle reduces idle time. As the back-working turret finishes an operation and indexes, the concave section immediately vacates the working zone allowing the rear spindle to simultaneously feed forward to gain access to any rearward facing tools mounted on the main turret while its forward facing tools are still engaged with the main spindle. By installing the off-centre collet in the rear spindle and executing an up to 70 mm, X-axis shift, off-centre machining, contouring and parting-off using an endmill rather than conventional blade can be performed. The turret will accommodate drills up to 13 mm diameter and taps up to M8 by 1.25 mm, while delivering up to 20 Nm of torque via the 2.5 kW motors in its driven tool stations, each capable of 6,000 rpm. To accommodate non-bar work with automatic transfer between the two spindles, a 5 in chuck can be mounted on both the main and subspindle enabling larger billet type work, up to 90 mm diameter, to be machined.