GlossaryKind of term: Manufacturing term5-axis milling
What is 5-axis milling?
In 5-axis milling the machine drives two rotary axes besides the three linear ones, so the tool can meet the workpiece at changing angles.
The rotary axes let the tool axis tilt relative to the workpiece. It is used in two ways: in 3+2, the rotary axes lock the part in a fixed orientation and the machine then mills with three axes; in simultaneous 5-axis, the rotary axes move during the cut. Both make more sides reachable in one setup, but the clamping face itself stays out of reach.
How is a 5-axis machine built?
The rotary axes sit in the table, in the head or one in each; a trunnion table is common on smaller machines. The kinematics set the tilt range, the largest part and where collisions become a risk. Whether a feature can be reached depends on that range, tool length, the workholding and the rest of the part. Simultaneous work is used for free-form surfaces, for flank milling angled walls and to reach deeper with a shorter tool; it asks more of CAM, the postprocessor and simulation. Accuracy between orientations depends partly on how well the rotary axes are calibrated.
How does 5-axis milling work in practice?
Fewer setups can mean less setup time, less risk of a position error between features from different setups, and a shorter lead time, although a 5-axis setup can itself take more preparation. Against that are a higher hourly rate and usually more programming time, more still for simultaneous work. Tilting the part can shorten tool overhang, which can help cutting data and surface finish. Against a 3-axis machine running more setups or a fixture, the comparison comes out differently case by case, with quantity, hourly rates, programming time and workholding.
What is 5-axis milling often confused with?
5-axis milling is not mill-turn: a mill-turn machine spins the workpiece to cut diameters, an ordinary 5-axis machine does not, although some 5-axis machining centres have a rotary table that can also turn. Nor is 5-axis automatically simultaneous: 3+2 uses the same machine with the rotary axes stationary during the cut.
How do you see 5-axis milling in Blake?
In Blake the 5-axis machine sits in your machine park with its envelope and axes, and the first check per machine names the limit that decides. You enter and accept the setups per route; setup, machining and programming appear as separate lines in the estimate, per piece and per batch, all labelled as estimates. More on milling.
Frequently asked questions
Is 3+2 also 5-axis?
Yes, it is one way of working 5-axis: the rotary axes lock the part in a fixed orientation and the machine mills with three axes. That suits many prismatic parts; simultaneous work is needed when the tool angle must change during the cut.
Does a part come out more accurate on a 5-axis machine?
Not automatically. Fewer reclamps avoid position errors between setups, but the rotary axes bring errors of their own. How accurately features from different orientations relate comes down to the machine, its calibration, temperature and the workholding.
Is a 5-axis machine cheaper when it saves setups?
Often on one-offs and small batches, when the setup time saved outweighs the higher hourly rate and the programming time. On larger batches a 3-axis machine with a fixture can be cheaper. The workholding you already have counts too.