Multi-Axis CNC; A type of computer-controlled machine tool that is used for cutting and shaping metal, typically uses both rotating cutting tools and rotating workpieces, Can be used for wide range of applications, very common in most manufacturing industries. Multi-Axis CNC machines can be categorized in several ways, number of axes and their additional axes. Dedicated multi-axis CNC's are machines that incorporate all their axes, Plus multi-axis CNC are machines that have added axes. Using multi-axis CNC's Increase Flexibility, Improved Efficiency, Enhanced Accuracy, Reduced Tooling Costs, Versatility, Shortened setup Time, Reduced Scrap and Material Wastes.Overall, multi-axis CNC machines offer greater versatility, efficiency, accuracy, and cost-effectiveness compared to single-axis machines. They empower manufacturers to produce complex and precise parts with improved productivity, reducing both time and costs in the manufacturing process.
The two most common kinds of multi-axis CNC mills are the 4 axis HMC and 5 axis VMC. Mill-Turns combine the functionality of CNC lathes and CNC mills there are two categories. Lathes that can mill and Mills that can turn, lathes use live tooling to mill there are two different live tooling axial live tools which are fixed parallel with the turning spindle axis, and radial live tools which are fixed perpendicular to the turning spindle. Also lathes use Milling spindles a separate milling spindle which can achieve part features comparable to a 5 axis. Mills that can turn use high rpm rotational axis and indexable turning tools/spindle, rotational axis rotate an axis at high enough RPM's mill can efficiently utilize non rotating cutting tools to turn, Indexable turning tools fixing a nonrotating single point turning tool in a milling spindle the tool then can be used to turn spinning material. Robots can be used for machines, learning to program a robot to execute subtractive toolpaths is similar to programming a robot to execute additive toolpaths. 6-axis Industrial robot arms are the most common type of robots used for subtractive manufacturing.
Positional multi-axis machining is the most common way multi-axis CNC's are used today, it involves positioning one or more axes to a fixed location after which the remaining axes are used while the other ones stay locked. Programming positionally is defining a new plane, then proceeding with regular 2D and 3D toolpaths on the need plane. Positional is great because it can take may operation 3-axis down to 1 or 2 operations.
Rotary Indexers are devices that let the workpiece be rotated around a specific axis. they typically have a chuck or collet to hold the workpiece securely. Indexers can be programmed to rotate the workpiece at specific angles, allowing machining operations to be performed on multiple sides without the need for manual repositioning. Advantages: Simple to set up and use, provides precise angular positioning, suitable for high-volume production of parts with similar features. Limitations: Limited to rotational movement only, may not be suitable for complex geometries requiring tilted angles.
Trunnion Tables are mounted on the machine table and can tilt about a rotary axis. This provides flexibility in positioning the workpiece, enabling machining operation on multiple faces with complex geometries. Advantages: Enables multi-axis machining in a single setup, versatile for a variety of part geometries, reduces the need for multiple setups. Limitations: May require additional setup time for complex parts, limited in size for very large workpieces.
Tombstone Fixtures are vertical fixtures with multiple sides, each containing clamping surfaces. These fixtures are mounted on the machine table and can hold multiple workpieces simultaneously. The sides of the tombstone can be machined in a single setup. Advantages: High production throughput, Simultaneous machining on multiple workpieces, reduces the need for frequent tool changes. Limitations: limited to parts that fit within the tombstone envelope, challenging for parts with irregular shapes.
Pneumatic or hydraulic vises with rotary axes are traditional vises that are enhanced with rotary axes, allowing the workpiece to be rated during machining. Pneumatic or hydraulic actuators enable quick and precise adjustments. Advantages: Combines traditional vise clamping with rotary movement, simplifies setup for parts requiring rotation, versatile for various part geometries. Limitations: Limited to the size and weight capacity of the vise, may not be suitable for large or heavy workpieces.
Custom Fixtures are design to the specific requirements of a workpiece. These car include a combination of rotary and tilting elements to achieve the desired machining orientation. Advantages: Adaptable to a wide range of part shapes, offers flexibility in holding a positioning, can optimize setup for specific machining operations. Limitations: Design and fabrication may be time-consuming, may have a higher initial cost for custom solutions.