What is the difference between 3-axis, 3+2-axis and 5-axis machining in CNC machining centers?
Many people new to the CNC machining industry inevitably find it difficult to distinguish between 3-axis, 3+2-axis, and 5-axis machining options. In fact, even veterans, not to mention beginners, often struggle to distinguish. This article summarizes the key points in detail. Take a look!
What is 3-axis machining?
3-axis machining uses the linear feed axes X, Y, and Z. Machining characteristics: The cutting tool orientation remains constant throughout the entire cutting path. Perfect cutting conditions at the tool tip cannot be achieved in real time.
What is 3+2-axis machining?
Two rotary axes initially secure the cutting tool in an inclined position, while the feed axes X, Y, and Z perform machining. This type of machine is also called a positionable 5-axis machine and can be programmed using Siemens' CYCLE800 function. CYCLE800 is a static plane transformation that allows 3+2-axis machining (such as a swivel head or rotary table) to define a rotating work plane in space. 2D or 3D machining operations can be programmed within this work plane.
Machining Features: The rotary axis always rotates to a position where the machining plane is perpendicular to the tool axis for machining, and the machining plane remains fixed during machining.
5-axis machining involves linear interpolation of any five of the feed axes (X, Y, and Z) and the rotation axes (A, B, and C) around them. Siemens' TRAORI motion transformation command effectively supports 5-axis transformation.
Machining Features: The tool orientation can be optimized along the entire path, while simultaneously performing linear tool movement. This ensures optimal cutting conditions throughout the entire path.
5-Axis Simultaneous Machining of 28 Parts
How do the advantages of a five-axis machine manifest? Here's an example of a Haas UMC-750P machine simultaneously machining 28 parts. By designing the rotary table and fixture, and by combining the three machining surfaces of a part into a single five-axis program, cycle time is reduced.
The rotary table can expand the existing machining space through precise positioning. A well-designed fixture not only improves machining efficiency but also reduces machine downtime, freeing up operators.
For example, machining the first three sides of a part like the one shown below, using a vise, takes a total of 264 seconds per part (not including setup time).
By designing a more compact fixture and fully utilizing the machining space provided by the rotary table, it is possible to process 28 parts simultaneously.
To construct the fixture, an aluminum alloy base measuring 114mm x 114mm x 550mm is used. Dowel pins are used for positioning, and a clamping fixture that takes up less machining space is selected for faster setup.
The base is then milled flat on all four sides. For each part, a dowel pin hole, two slots for securing the fixture, and two threaded holes are machined. If you're interested in learning UG programming, contact QQ group 304214709.
The fixture consists of 28 locating pins, 56 reusable locating and locking blocks, 56 screws, and a wrench. This fixture design reduces the original machining time from 264 seconds to 202 seconds (excluding setup time), representing a 23.5% reduction in machining time.
Furthermore, because the machining program combines the three machining surfaces of the part into a single process, the cycle time for a single program is reduced to 95 minutes. During this time, the machine maintains machining without requiring frequent setups by the operator, significantly reducing operator workload.