High productivity machines from Japan

This year OKK is celebrating 100 years of machine tool operations, and the corporation has linked the launch of the HM-X8000 tilting-head, 5-axis machining centre to this anniversary dedicated to high productivity. The machine offers high precision cycles through a rigid 30 tonne structure.

The -110° to +40° A-axis spindle head is able to tilt between horizontal and vertical positions creating increased levels of flexibility. It also enables high precision operations to be carried out due to its advantage of greater stability compared with when moving elements support the workpiece such as rotational and tilting movements of the more common trunnion unit.

The HM-X8000 has an 800mm by 800mm table (B-axis), with 360° rotation and will accommodate parts weighing up to two tonnes and 1,200mm diameter by 1,250mm high. This unit is serviced by axis travels of 1,300mm in X, 1,100mm in Y and 1,550mm in Z with rapid traverse rates of 48m/minute.

The 45kW, 50 taper 12,000rpm spindle will accept tools up to 25kg, 115mm diameter by 400mm long or up to 270mm diameter with adjoining pockets left empty. Tool to tool time is rapid at 2.8 seconds and up to 60 tools can be held in the magazine.

Ergonomic access to the machining area is good with a 1.5m opening door width and due to the tilting spindle structure, excellent visibility is given to the cutting zone.

Another addition to the 2DCNC portfolio is the OKK VC-X350 vertical machining centre which has been developed for machining high alloy type materials. The machine is ideal for complex mould and die type applications and where precision turning can be combined as part of a 5-axis production cycle, utilising the direct drive rotation of the trunnion mounted C-axis at up to 1,000rpm.

This compact, high rigidity machine has axis travels of 600mm in X, 430mm in Y and 460mm in Z with rapid traverse rates of 50m/minute in X and Y and 36m/minute in Z.

As standard, the 7.5kW spindle drive has a speed range between 100 and 12,000rpm with two further higher power 22kW motor spindle options delivering either 12,000 or 22,000rpm. Tool capacity as standard is 30 positions through a cam-controlled high-speed synchronised change mechanism which takes just 1.3 seconds. There are further tool magazine options of 60, 80 or 120 units.

The trunnion unit has a 350mm diameter rotary table with the tilting A-axis enabling -120° to +30° of movement with higher power 1,500Nm hydraulic clamping. In addition, the 360° rotational C-axis incorporates a 500Nm air clamp. To ensure a highly stable turning function able to maintain a close tolerance and surface finish, the direct drive main spindle uses hydraulic disc clamping. By incorporating double anchored ballscrews for the X-, Y- and Z-axes with each ball crew core chilled to supress and stabilise positioning, this feature reduces any likelihood of elongation.

As a result, combined with high orders of build standard and inherent rigidity of the proven design, positioning accuracy in X, Y and Z is within ±0.0020mm and repeatability within ±0.001mm. By incorporating the optional linear scales positioning accuracy is increased to ±0.001 and repeatability to ±0.0005mm. The accuracy of the trunnion A-axis is ±5 seconds and the C-axis ±10 seconds.

2DCNC www.2dcnc.co.uk