CNC machining order arrangement principle

The arrangement of is considered based on the structure of the part, the blank state and the needs of positioning and clamping the CNC machining sequence , and emphasizes that the rigidity of the workpiece is not damaged. The order of procedures should usually follow the following principles:

1: Basic Principle

At the beginning of processing, first process the fine base surface, because the more precise the reference surface, the smaller the clamping error. Therefore, any CNC precision parts must be roughly processed and semi-finished, and if necessary, also finely processed. For example, box parts generally first process the positioning plane and two positioning holes, and then use the plane and positioning holes as the precision reference processing hole system and other planes. If there are more than one fine base surface, it will be based on the order of base surface conversion and step by step The principle of improving processing accuracy is to arrange the processing of the base surface and main surfaces.

2: First thick and then thin

The processing order of each side is carried out in order of rough processing and finishing processing to gradually improve the accuracy of the processing surface and reduce surface roughness.

Three: Principle of first and second

The accuracy requirements for the parts surface and assembly surface are high, and they are the main surfaces and should be processed first to detect possible defects on the main surface of the blank as early as possible. The accuracy requirements for surfaces such as empty surfaces, keyways, closed screw holes, and light air surfaces are not high. They are secondary surfaces and can be interspersed. They are generally arranged to be fine-processed after the main processing surface reaches a certain accuracy.

Four: Principles of Front and Back

For box, bracket and body parts, the plane size is relatively large, and generally the size of the processing surface first, then the processing holes, etc. Therefore, on the one hand, it is positioned with a processed plane, which is stable and reliable; on the other hand, it is easier to process holes on the processed plane, and the machining accuracy of the holes can be improved, especially when drilling, the hole shaft is not easily inclined.

Five: Principle of Preconceived

That is to say, the inner cavity processing process is performed first, and then the outer model processing process is performed.

6: The processing of the previous process does not affect the positioning and clamping of the next process.

7: The same installation method or the same tool processing process is best carried out continuously to reduce the number of repeated positioning times.

8: When performing multiple processes during the same installation process, the process that less damages the rigidity of the workpiece should be arranged first. In addition, when arranging the CNC processing sequence, pay attention to the arrangement of operations such as tool retracting grooves and chamfering.