What is the difference between three axis, three + two axis and five axis?
What is the difference between the usual 3-axis, 3+2-axis, 5-axis and other machining solutions we often mention? First of all, let us introduce to you.
3-axis machining method
3-axis machining by linear feed axes X, Y, Z for processing. Machining characteristics: The cutting tool direction remains constant during the movement along the entire cutting path. The cutting state of the tool tip is not possible to achieve perfection in real time.
3+2 axis machining method
The two rotary axes first fix the cutting tool in an inclined position, and then the feed axes X, Y and Z are used for machining. This type of machine, also called a positioning 5-axis machine, can be programmed for machining using the CYCLE800 function from Siemens. CYCLE800 is a static plane conversion that allows the definition of a rotating working plane in space by 3+2-axis machine machining (e.g. rotary head or rotary table). In this work plane, 2D or 3D machining operations can be programmed.
Machining characteristics: 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 consists of linear interpolation motion of any 5 of the feed axes X, Y, Z and the rotary axes A, B, C around X, Y, Z. The 5-axis conversion is well supported by Siemens’ motion conversion command TRAORI.
Machining features: The tool direction can be optimized during the movement along the entire path, while the tool is moving linearly. This allows optimal cutting to be maintained along the entire path.
5-axis simultaneous machining of 28 parts
So how do the advantages of a 5-axis machine manifest themselves? Here we share an example of a Haas UMC-750P machine machining 28 parts at the same time. The reduction in cycle time is achieved through the design of the rotary table and fixture, and by combining the three machined surfaces of the part in a single machining program in a 5-axis machining program.
The turntable can expand the original machining space through precise positioning. A well-designed fixture not only increases the efficiency of machining, but also reduces machine idleness and the operator can take time out from it
For example, machining the first three faces of a part like the one shown below would take a total of 264 seconds per part (clamping time not accounted for) if using the vise clamping method.
By designing a more compact fixture and making full use of the machining space provided by the rotary table, the opportunity to machine 28 parts at a time was possible.
For the fixture, an aluminum alloy with dimensions of 114mm*114mm*550mm was chosen as the substrate, positioning pins were chosen for positioning, and a clamping fixture that takes up less machining space was chosen for faster clamping.
Then milling the four sides of the substrate, machining a positioning pin hole for each part, two slots to avoid empty locking fixture, and two threaded holes for locking, this is all the production steps.
The complete set of the fixture consists of 28 locating pins, 56 locating locking blocks (reusable), 56 screws and wrenches. This fixture design was able to reduce the original machining time of 264 seconds to 202 seconds (clamping time is not counted). This means that the machining time has been reduced by 23.5%.
Not only that, but because the machining program has combined the three machined sides of the part in one machining program, the cycle time for a single program becomes 95 minutes, during which the machine is kept machining without waiting for frequent clamping by the operator, which will greatly reduce the operator’s labor.
Source: China machining solutions provider – Yaang Pipe Industry (www.machinedsgn.com)
