Mollart commissions 5-axis bed-type combination deephole drilling machine/machining centre

The over 22 tonne Mollart Prismabore machine will extend Mollart's single cycle production capability to combine milling sequences on components weighing up to 8 tonnes with deep hole drilling and boring of holes between 6 mm and 40 mm diameter by 1,500 mm deep. Typical components to be machined will be recent orders taken for multi-feature Inconel and titanium parts and the combined drilling of extended depth cooling holes and milled features on complex mould plates. The Mollart Prismabore cost some £700,000 to develop and build. It has a 1,250 mm by 1,250 mm B-axis rotary table with axis strokes of 2,000 mm in X, 1,000 mm in Y and a ramslide creating a Z-axis stroke of 800 mm. In addition, a fully independent U-axis governs the penetration of the gundrill to a depth of 1,500 mm. High accuracy positioning is incorporated through the inclusion of Heidenhain glass scales for X, Y and Z-axes. The ISO 50 taper machining centre spindle is powered by an 11 kW, 6,000 rpm motor, supported by a 20-tool magazine and swinging arm toolchange. Both spindles are controlled by a single Fanuc 31i Model B unit. The 11 kW gundrill drive has a two-speed gearbox to the spindle giving a 1:1 ratio with a maximum speed of 1,500 rpm with higher torque or 4:1 high speed ratio giving between 1,500 and 6,000 rpm. Tool monitoring extends through spindle power draw, percentage tool loading, feed rate and coolant pressure in order to protect the tooling and high value components that will pass through the machine. It has 80 bar coolant supply to both spindle arrangements with refrigeration and 20 micron filtration. In addition a sub-micron Micromag filter unit is incorporated into the coolant circuit.