AMB Large portal machine provides top surface finishes, accuracy
High-stability plays a central role in the unit's dynamics and precision.
F. Zimmermann's FZ 33 portal milling machine is designed for fast, complete five-sided machining of aluminium and composite materials, and for finishing steel and cast using high-acceleration simultaneous operation. The unit is said to feature work areas with up to 40,000 mm on the X-axis, 5,000 mm on the Y-axis and 2,500 mm on the Z-axis.
On the X-axis, the unit has a weight-balanced, structurally-stiff overhead gantry for high dynamics and precision. The gantry design, with a fixed machine bed, and an upper driven portal that travels in X-direction, offers decisive advantages for the manufacture of tooling and moulds, according to the supplier. It said the cast machine bed is securely anchored to the foundation, so the workpiece does not move. Machining is independent of the weight of the workpiece.
The moving mass is made up of the structurally-stiff portal, the cross-slide, the Z-axis ram, and the milling head. The constant mass ratio implies unchanging dynamic behaviour; this is a prerequisite for machining workpieces which require an optimum of surface finish and accuracy, according to the supplier.
High stability and stiffness, constant moving masses, and highly dynamic drives allow high-precision machining of materials such as cast and steel, aluminium, Zamak, composites, and plastics. Reworking is said to be kept to a minimum. The company's V20 milling head is said to feature an A-axis drive with two electronically pre-loaded, back-lash free torque motors. The C-axis drive has a direct drive torque motor for rotary movements of up to 360°/sec. The unit features clamping of the axes with a holding torque of 3,000 Nm.