All milling machines operate on the same subtractive principle: they work a geometric shape out of a blank by removing material until that shape is complete. The more complex the geometry of the desired part, the more difficult it is to produce. On a conventional 3-axis milling machine, such workpieces would have to be clamped in different positions to achieve the desired geometries. This is usually very time-consuming or not even feasible, for example, in the case of curved shapes. The solution entered the market with the first multi-axis machining centers. They have rotary axes that allow rotation around the X, Y or Z axis. Of these axes, labeled A, B and C, two are sufficient to position a workpiece in space as required. These 5-axis machining centers are now a common standard in many manufacturing operations.
5-axis machining centers are available in a wide variety of versions: with horizontal or vertical tool spindle, with swivel rotary table or as a gantry machine with rigid table. Which version is the right one can be determined by the component requirements. The common feature of all designs is that they machine a workpiece from five sides – i.e. completely down to the clamping surface. With this feature, 5-axis machines are an efficient response to a continuing trend that ultimately also results from manufacturing possibilities: Workpieces are becoming increasingly complex.
3 + 2 ≠ 5
The simplest 5-axis machines have three linear axes and two rotary axes, which can be used to set the workpiece in any position. However, the total of five axes do not move simultaneously with the machining by the tool. This is necessary when so-called free-form surfaces come into play. PET bottles, dashboards or plastic toys are just three examples of products that are manufactured with tools that have such curved free-form surfaces.
Based on 5-axis machining centers with three plus two axes, machine tool manufacturers developed CNC machines in the early 1990s that allow interpolation of the five axes. That is, as soon as a rotary axis rotates, the orientation of the linear axes is continuously adjusted. This enables continuous machining of randomly shaped surfaces – the main feature of 5-axis simultaneous milling. The technology was a revolution that still sets standards in manufacturing today, because even the most complex geometries can be machined highly economically and with first-class surface finishes in a single setup.
Over 30 years of experience in 5-axis milling
DMG MORI concentrates its experience and competence in 5-axis machining in around 15 series. Even with the entry-level CMX U series, users benefit from free positioning of their workpieces, while the DMU 50 2nd Generation marks the entry into 5-axis simultaneous machining. The high-tech machines of the DMU monoBLOCK series are in such high demand that DMG MORI has set up the monoBLOCK Excellence Factory monoBLOCK in Pfronten to meet the increasing demand. The high-precision NMV and DMU eVo models, and HSC 20 linear complete the product range, as do the DMF travelling column machines and the XXL portfolio around the portal and gantry machines. This means: DMG MORI offers the suitable 5-axis machine for every application – on request in an automated version to further increase the productivity of the innovative manufacturing technology.