A 5-axis mill-turn centre for one-hit machining of components up to 710mm in diameter by over 1.5m long features advanced collision avoidance - the CNC monitors the machining area in real time.

Okuma has launched a new mill-turn centre for one-hit machining of components up to 710mm in diameter by over 1.5m long. Called Multus B400, the 5-axis machine features advanced collision avoidance whereby the Okuma OSP-P200 control monitors the entire machining area in real time during an automatic machining cycle or, unusually, in manual mode as well, preventing the axes from being wound by hand into a collision situation. Availability in the UK is through sole agent, NCMT.

Whereas the focus of competitive simulation and interference-checking software is on the tool, holder, spindle and fixture, in addition to the component, Okuma takes a wider view, mapping also the spindle head, slideways and guarding.

The result is a reduction of up to 40% in the time needed to write programs involving the simultaneous interpolation of multiple axes.

In place of a turning tool, the swivelling B-axis spindle accepts HSK-A63 (CAPTO C6) tools, exchanged from a 20-station (optionally 40- or 80-station) magazine, for carrying out heavy prismatic machining operations using 10kW (optionally 14kW) of power.

The milling spindle swivels from -30 to +195 deg in 0.001 deg increments.

Both the tool and the motion of the turret are powered by one Prex reluctance motor (Okuma patent), whose absence of windings on the rotor minimises heat generation and promotes accuracy.

Roller bearing linear guideways allow weight-bearing capacity and precision to be combined with 40m/min rapid traverse in X and Z, 26m/min in the +/-115 mm Y-axis, leading to short idle times.

As befits a machine required to turn large components, the C-axis spindle is powered by either a 30/22kW or 22/15kW motor, switchable in two ranges, the former figures representing 30 min ratings.

The 14.5-tonne, slant-bed machine is capable of high accuracy in a normal shop floor environment, as tests have shown thermal deviation to be less than 10 microns over a 24h period despite a variation in ambient temperature of 8 deg C.

This performance is a result of the application of Okuma's patented Thermo Friendly Concept to both the machine structure and the spindle, together with the use of 0.1 micron resolution linear scales in the orthogonal axes.

Big, complex machines can often be cumbersome to use, but not so with the Multus B400.

Spindle centreline is only 1.2m from the floor and 550mm in from the guarding, there is a lightweight door for ease of use, and a coolant tank that detaches from the front, rather than having to slide it out lengthways.

There is also a convenient, swivelling operator's panel for the Okuma OSP-P200 control, which uses an industrially hardened PC to run both the Okuma operating system and Windows XP.

It is therefore possible to display Excel files listing machining instructions, tooling, offsets and performance results.

Two USB 2.0 ports are provided for program download, data capture and even the attachment of a bar code reader.