Emerald Group Publishing Limited
Copyright © 2008, Emerald Group Publishing Limited
Five-axis, high-speed machining centre
Article Type: Aerospace technology From: Aircraft Engineering and Aerospace Technology: An International Journal, Volume 80, Issue 3.
A new, five-axis CNC machining centre called ANTARES, intended for machining non-ferrous materials within a 2,600 x 1,500 x 1,200mm working envelope, was presented by the Italian manufacturer, CMS, at the recent MACH 2008 (Figure 7).
Figure 7 The new ANTARES five-axis machining centre was the focus of the CMS stand at MACH 2008
According to CMS, UK General Manager Toni Nagiel, the concept deliberately tends towards “over- engineering” to provide a high degree of robustness, reliability and accuracy. The machines can therefore be used for a wider range of applications than might previously have been envisaged. Confidence in their capabilities is, he says, being borne out by their increasing use in high-technology industries.
Materials regularly machined now extend from wood, aluminium, epoxy paste and polyurethane, commonly found in the mould-, model- and pattern-making sectors, to include light alloys and carbon fibre, as used for the production of structural components in aircraft, for example.
One result of the ANTARES design philosophy is to afford a far higher degree of stiffness to the five-axis cutting head than is normally associated with machines of this type. The usefulness of this attribute is enhanced by the inclusion of a pneumatic brake that can be programmed to clamp the B- and C- axes during operations that do not require fully active five-axis interpolation.
The PX5 universal head, with all five axes acting under simultaneous control from a GE-Fanuc 18i MB5 CNC system, has a fourth, horizontally rotating axis and a fifth that inclines the spindle in the vertical plane, in addition to the three orthogonal linear axes. The highly specified NC control comes complete with PC Office integrated in the electrical cabinet.
Drawing on the machine tool builder's 35 years of experience, a strong spindle shaft, manufactured in-house, is mounted on two pairs of pre-loaded bearings ceramic for the front pair and steel for the rear. The high-speed spindle (24,000rpm max 12kW or 27,000rpm max 6kW) is liquid cooled (Figure 8). Fast positioning speeds of 70-80m/min are achieved along with acceleration of up to 3.0m/ s2. These are higher if a customer chooses the option of linear motors in X and Y.
Figure 8 A CMS liquid-cooled PX5 spindle (24,000rpm max 12kW) is standard on the ANTARES five-axis CNC machining centre
Special cycles produced by CMS for surfacing work are linked to the high- speed cutting strategy from Fanuc. It allows the programmer to vary cutting feed rates on the same tool path to optimise both roughing and finishing operations, leading to major productivity gains and high levels of surface quality. Roughing times are typically half those of finishing cycles.
Automatic tool change is from a magazine located on the front face of the traverse. An eight-tool magazine is standard; a 16-tool version is optional.
According to CMS, the combination of a high performance, powerful electro spindle and high-machine rigidity assured by the travelling bridge construction offer users high-quality machining across a wide range of materials.
Having extended its target markets well beyond the original woodworking and routing, CMS is benefitting from increased machine sales. Said Toni Nagiel: “We are challenging manufacturers to look again at their previous understanding of what type of machinery they need.”
“We are regularly showing that, for many high-speed machining applications, equipment with large- volume working cubes such as the ANTARES can be just as effective as higher-priced, `traditional' 5-axis machining centres.”
He mentioned that there can be benefits to manufacturers if they broaden their outlook. He cited instances where the standard vacuum bed, for example, has provided an unexpectedly easy way for customers to clamp large components and save on tooling costs and downtime.
He continued, “Of course, tee-slotted and other tables are available as well, but production staff owe it to their companies to look at all options. By dealing with CMS at its Nottingham base, they are talking directly to the machine supplier and are offered full technical advisory and after-sales services.”
For further information, please contact: CMS Group (UK) Ltd, Tel.: +44 (0) 115 9770055, Fax: +44 (0) 115 9770555.