Pioneers in Machining Technology
NCMT SHOWCASED OKUMA LATHES AND MACHINING CENTRES
Multus U4000 1SC multi-tasking turn-mill centre
On show for the first time at a national exhibition in the UK was the Multus U4000 multi-tasking turn-mill centre from Japanese machine tool manufacturer, Okuma. Sole agent NCMT says that the machine is designed for complete machining of workpieces up to two metres long and 650 mm in diameter, but that a smaller U3000 can be supplied offering up to 1,500 mm between centres.
The variant exhibited was the single tool carrier model, Multus U4000 1SC, with a 22 kW / 12,000 rpm B-axis motor spindle that develops 120 Nm of torque. The spindle uses the HSK-A63 tool interface (optionally Capto C6), has 0.001-degree indexing and swivels through -30 to +210 degrees, providing considerable versatility of machining. The tool magazine has 40 stations as standard but options for 80 and 120 ATC.
The 22 kW main spindle has a 91 mm bore (optionally 112 mm) and generates 700 Nm of torque at up to 4,200 rpm. Alternatively, a 32 kW drive can be specified, providing a torque of 955 Nm. Servo motors deliver feed rates of up to 50 m/min in the X and Z axes, 40 m/min in the 300 mm Y-axis. Together with the C-axis on the main spindle, the machine is capable of fully interpolative, 5-axis (X,Y,Z,B,C) machining of freeform surfaces, with SuperNurbs smoothing.
The specification of Multus U can be extended further, giving users an ex-works product that is closely tailored to their needs. For example, a lower turret can be supplied, having 12 live tool stations and a 7.1 kW / 40.4 Nm / 6,000 rpm drive. A counter spindle can be ordered in place of the tailstock.
Tests have shown thermal deviation to be less than 10 microns over a 24-hour period, despite a variation in ambient temperature of 8°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.
The machine has the added benefit of the manufacturer's OSP-P300 control, which uses an industrially hardened PC to run both the Okuma operating system and Windows. A feature of the control is the most comprehensive collision prediction and avoidance system currently available. The entire machining area right out to the spindle head, slideways and guarding is monitored in real time during an automatic machining cycle or, unusually, in manual mode as well, preventing the axes being wound by hand into a collision situation.
Eccentric turned features machined on turn-milled parts
A highlight of the control that is new and was on show for the first time in the UK is Okuma’s TurnCut software for turning machines. It is already well known on the manufacturer’s machining centre platforms, on which the X and Y axes are interpolated while the spindle carrying a turning tool rotates at the same speed and is fed forward in Z to generate straight, tapered or profiled features on inside or outside diameters.
Now, similar software allows such features to be created on a turn-milled part, either off-centre on its end or at any cross angle, by interpolating the linear motions of the B-axis while rotating the tool spindle at the same speed. A demonstration cycle will be running on the Multus U4000 1SC at the show.
Okuma Genos L200E-MY entry-level lathe
NCMT exhibited for the first time in the UK the L200E-MY turning centre from the early-entry Genos range of machine tools built by Okuma. The lathe programme offers various combinations of spindle, bed size, tool turret, static or driven tooling, Y-axis, and tailstock or counter spindle. There is also the option of robotic or other automated systems for workpiece load / unload.
The Genos model exhibited at this year's show is for machining components up to 200 mm diameter and 380 mm long. It also has a C-axis and 80 mm of Y-axis travel on the 12-station tool turret.
As with all machines in this series, it has fewer standard functions and options than other Okuma lathes, allowing a lower price to be achieved. There has, however, been no compromise on build quality. Constructed on a one-piece, cast iron base with hand-scraped headstock and tailstock mounting surfaces, the machine provides stability, rigidity and accuracy.
Okuma is known for manufacturing and hence being able to control the quality of many components that go into its machines, including drives, encoders, scales, and ballscrews. These are also to be found in all Genos products.
Genos M560-V vertical machining centre
Highly rigid, thermally-stable construction protects this Okuma vertical machining centre from thermal deformation, resulting in high machining performance for an entry-level machine. It nevertheless is designed on the Thermo-Friendly Concept and is controlled by the user-friendly OSP-P control. The machine handles a variety of materials, from titanium to aluminium, and does so without sacrificing dimensional accuracy, finish quality or productivity.
The M560-V has a 1,050 x 560 x 460 mm working envelope and maximum table load of 900 kg. The CAT40 BIG Plus, 15,000 rpm spindle moves in the X and Z axes, with the table moving in Y. A 32-position tool magazine is provided.
Software can be added, including Machining Navi to minimise chatter by finding the best cutting conditions. It employs a microphone to detect the onset of vibration and feeds information back to the control. A change in either spindle speed or feed rate is recommended so that the adjustment can be set manually to suppress the chatter, or adjustments are applied automatically.