Emag’s New Machining Centers Apply Simultaneous Five-Axis Machining
August 30, 2007—
EMAG’s BA S03 vertical machining center is designed as a monobloc enclosed on three sides and topped by a gantry and combines a minimal footprint, extreme rigidity and protection of guideways and drive components against the ingress of chip particles and coolant.
Its degree of rigidity is increased by the box-in-box design of the three-axis unit and features ball screw drives in the linear and direct drives in rotary axes. The torque drives guarantee backlash-free operation and a gantry drive in the Y-axis ensures parallel movement of the slide even where cutting forces exert off-center pressure. The direct drives for the swivel axes, in conjunction with direct measuring systems, offer a positioning accuracy of +/-5 angular seconds. This ensures the positioning accuracy Tp achieved in the machining area of the BA S03 is 0.01 mm to VDI DGQ 3441. The acceleration of up to 10 m/s2 linear axis speeds of max 75 m/min and rotary axis speeds up to 50 rpm ensure that idle times are kept to a minimum.
The company has been offering manufacturing solutions utilizing twin spindle five axis machining processes since 2004.
“Our twin spindle solution gives us an advantage over the single spindle process, especially when it comes to manufacturing of impellors, which calls for relatively few tools. All it usually involves is between three and five tool changes. With the SW chuck, the workpieces are quickly loaded and unloaded. In fact, the twin spindle design of the BAS03 allows us to double production times”, says Erik Pfeiffer, manager of technological development at Schwäbische Werzeugmaschinen GmbH.
According to the company’s press release, the SW is applicable for small batch production. Where parts are milled from solid stock, the raw material (aluminum or titanium) is held in two concentrically clamping universal chucks. Emag says this makes resetting quicker and easier as all components variants can be clamped in the same chuck.
To arrive at a cycle time that is as accurate as possible and generate and optimize the NC program in the early stages of the project, SW employs the 3-D machine simulation system eM RealNC for its five-axis machining operations. All NC axes are parameterized (speed, acceleration, jerk rate, V-constant, ect.) for the purpose. In the same way, movements of the chain type tool magazine are simulated to be able to assess the time taken for tool changes as accurately as possible. Canned cycles and subroutines are also displayed. Users find security in studying possible collision factors and reducing idle times. With the simulation, Emag aims for realistic cycle times that provide a basis for optimal capacity planning before a chip has fallen.