Citizen makes its mark on 10 plus 3 axes Miyano BNA-42GTY performance

Citizen explains that the savings achieved by the Miyano BNA-42GTY are purely due to faster processing and the ability to overlap more functions. These include axis movements and cutting tool engagement with up to three tools being in-cut at the same time with the main and sub-spindle. The BNA-42GTY is constructed on a heavy cast bed which carries the main and sub-spindle plus turret and toolslides on its platform-like surface table structure. The units are mounted perpendicular to the hand-scrapped mounting faces of the slideways, thus minimising relative deviations between workpiece and the engaged cutting tool. The Miyano BNA-42GTY has been designed to enable it to carry up to 45 tools in its standard specification. The eight station, 3-axis X2, Y2, Z2 turret has a half-index capability that creates up to 16 tool positions for presenting to the main and sub-spindle. However, with the use of a series of optional purpose-designed toolholders, up to four further tool positions can also be set on each turret station. All driven positions on the turret are powered by 1 kW, 6,000 rpm motors and the inclusion of a 70 mm-stroke Y2 axis further increases the levels of setting flexibility. In addition to the Y2 axis on the turret, X1 and Y1 axes are applied to a vertical gang tool slide able to carry three turning tools, three positions for driven tools powered by 1.5 kW motor, and a block toolpost with the capacity to hold seven further fixed tools. With these tooling arrangements and the capability to engage three cutting tools using the ability of the sub-spindle to precisely follow the turret while it is machining at the main spindle, the gang toolslide can also be included. As a result balanced cutting can be performed as well as features such as the simultaneous pinch milling of opposed flats on a component. The main spindle, mounted on a 110 mm-stroke Z-axis, is powered by a high torque 11 kW, 6,000 rpm motor and the 2-axis (X3 – 190 mm and Z3 – 360 mm) slideways that carry the sub-spindle which has a 5.5 kW, 5,000 rpm drive. The bar capacity is 42 mm with a 34/42 mm capacity in the sub-spindle.