Vertical machining centre has a monobloc structure enclosed on three sides and topped by a gantry to combine a minimal footprint with extreme rigidity and full protection of guideways.

Nowadays floor space requirement is one of the decisive criteria in choosing a suitable machining center. It is for this very reason that SW Schwaebische Werkzeugmaschinen, Waldmoessingen, Germany, developed their BA S03 series of vertical machining centers. The design - a monobloc enclosed on three sides and topped by a gantry - combines a minimal footprint with extreme rigidity and the safest possible protection of guideways and drive components against the ingress of chip particles and coolant.

Rigidity is achieved, to a large extent, by the box-in-box design of the Z-axis.

Two separate drives for the Y-axis ensure that the slide moves in true parallel, even when cutting forces exert off-centre pressure.

The direct drives for the swivel axes and direct measuring systems offer a positioning accuracy of +/- 5 angular seconds.

The overall positioning accuracy Tp in the machining area of the BA S03 according to norm VDI DGQ 3441 is 0.008mm.

Acceleration of up to 8m/s2 and speeds of max 75m/min in the linear and up to 50 deg/s in the rotary axes ensure that idle times are kept to a minimum.

The direct-drive main spindles reach speeds of max 17,500 rev/min and are at full power of 15.5kW (40% ED) as soon as they reach 2500 rev/min.

Tool receptors HSK 63 and a torque rate of 60Nm ensure that even larger tools, such as surface mills and face mills with blade inserts, can be used.

As an alternative to the standard spindles SW now offers one with more than twice the torque.

The machining centre automatically replaces tools of up to 7.5kg weight and 70mm diameter (max 160mm dia., where the adjoining space is available) from a tool magazine with 40 (optionally 64; on two-spindle machines 2 x 20, or optionally 2 x 32) storage positions.

Use of the pick-up principle, where the main spindle travels to the tool changeover station, minimises the time taken up by tool changes.

This ensures that the average chip-to-chip time is 3s.

The 600 x 400 x 400mm (X-, Y-, Z-axis) machining area of the single table version contains the fixture plate that carries fixtures and workpieces weighing up to 400kg and swivels 360 deg.

This variant is best suitable for prototype and small batch production.

Higher productivity levels and cycle-time concurrent loading/unloading can be achieved with the twin-table version, which features two fixture plates (A-axis) supported on both sides in a swivel trunnion.

These swing 180 deg from loading/unloading station to machining position in 3.5s.

The loading/unloading station is totally separate from the machining area.

Workpieces can be safely loaded and unloaded manually, by robot or with the aid of a gantry loader.

Equipping one or both of the fixture plates with additional rotary tables allows for workpieces to be machined from five sides and at any angle in a single set-up.

The interfaces for hydraulic and pneumatic actuation and clamping are integrated into swivel trunnions and fixture plates.

The optimal chip flow conditions in the totally enclosed machining area make the BA S03 machining center ideal for dry machining.

The through-spindle coolant supply uses either conventional coolants or aerosol lubrication in minimal dosages, both at a pressure of 120 bar.

The flexibility in their design principle make the machines of the BA S03 series from SW an ideal technically and commercially viable alternative to much larger and more elaborate machining centers, especially when it comes to the manufacture of smaller and medium size workpieces in changing batch sizes.