We often mention 3-axis, 3+2-axis, 5-axis and other processing solutions. What are the differences between them? Let me introduce them to you first.
3-axis processing method
3-axis processing is performed by linear feed axes X, Y, and Z. Processing characteristics: The direction of the cutting tool remains unchanged during the movement along the entire cutting path. The cutting state of the tool tip cannot be perfect in real time. Add WeChat: mvm9987 to get a CNC programming tutorial
3+2 axis processing method
The two rotating axes first fix the cutting tool in an inclined position, and then the feed axes X, Y, and Z perform processing. This type of machine tool is also called a positioning five-axis machine tool, and can be programmed using Siemens' CYCLE800 function. CYCLE800 is a static plane transformation that can define a rotating work plane in space through 3+2-axis machine tool processing (such as a swivel head or a rotary table). In this work plane, 2D or 3D processing operations can be programmed.Processing characteristics: The rotary axis always rotates to the position where the processing plane is perpendicular to the tool axis for processing, and the processing plane remains fixed during processing.
5-axis machining method
5-axis machining consists of linear interpolation motion of any 5 axes of the feed axis X, Y, Z and the rotation axis A, B, C around X, Y, Z. Siemens' motion conversion instruction TRAORI can well support 5-axis conversion.Machining features: The tool direction can be optimized while moving along the entire path, and the tool can move linearly at the same time. In this way, the best cutting state can be maintained throughout the entire path.
Five-axis simultaneous machining of 28 parts
How are the advantages of five-axis machines reflected? Here is an example of a Haas UMC-750P machine tool machining 28 parts at the same time. Through the design of the turntable and fixture, and the merging of the three machining surfaces of the part into one machining program in the five-axis machining program, the purpose of reducing the cycle time is achieved.
The turntable can expand the original machining space through precise positioning. A well-designed fixture can not only improve the efficiency of machining, but also reduce the idleness of the machine, and the operator can also be freed from it. For example, if the first three faces of the part shown in the figure below are processed, if the vise is used for clamping, each part will take a total of 264 seconds (clamping time is not counted). By designing a more compact fixture and making full use of the processing space provided by the turntable, there is an opportunity to process 28 parts at a time. In the production of the fixture, an aluminum alloy with a size of 114mm*114mm*550mm is selected as the base, a locating pin is selected as the positioning, and a clamping fixture that occupies less processing space is selected for faster clamping. Then the four faces of the base are milled flat, and a locating pin hole, 2 slots for avoiding air locking fixtures, and 2 threaded holes for locking are processed for each part. These are all the production steps.
The complete set of fixtures includes: 28 locating pins, 56 locating locking blocks (reusable), 56 screws, and wrenches. Such a fixture design can shorten the original processing time of 264 seconds to 202 seconds (clamping time is not counted). This means that the processing time has been reduced by 23.5%
Not only that, because the processing program has combined the three processing surfaces of the part into one processing program, the cycle time of a single program has become 95 minutes. During this period, the machine has been processing without waiting for the operator to frequently clamp, which will greatly reduce the labor intensity of the operator.
