2022 – Page 4 – CNC Machining & Turning, Milling, Metal parts

CNC processing stage division stage

During the hardware processing, the production and processing stages of hardware processing are divided into the following stages:

(1) Ensure the processing quality of hardware accessories

During rough machining of hardware parts, the metal layer cut out is thick, the cutting force and tightening force are large, and the cutting temperature is high, which will cause large deformation. According to the processing stage, the processing error caused by rough processing can be corrected by semi finishing and finishing, so as to ensure the processing quality of parts.

(2) It is convenient to find the defects of hardware parts processing blanks in time

Various defects of the blank (such as porosity, sand inclusion and insufficient allowance of the casting) are found after rough machining, which is convenient for timely repair or scrapping to avoid unnecessary waste caused by further processing.

(3) Easy to arrange heat treatment process

After rough machining, stress relief heat treatment shall be arranged to eliminate internal stress. Before finishing, final heat treatment such as quenching shall be arranged. The deformation caused by heat treatment can be eliminated by finishing.

(4) Reasonable use of hardware accessories processing equipment

The rough machining allowance is large and the cutting amount is large. The machine tool with high power, good rigidity, high efficiency and low accuracy can be used. The precision machining has small cutting force and little damage to the machine tool. High precision machine tools are adopted. This gives full play to the respective characteristics of the equipment, which can not only improve productivity, but also prolong the use of precision equipment

CNC parts processing

Explanation of over cutting reasons of CNC machining parts

There are many reasons for over cutting of workpieces in CNC machining. If the workpieces are over cut, they can be processed after repair welding. If the workpieces are over cut, they can be directly scrapped. In particular, over cutting of workpieces during large-scale mold processing is the most troublesome thing. How to deal with it? Let me share with you the work experience summarized in CNC machining

Hardware processing

If the workpiece is over cut, it is caused by carelessness and forgetting to take the tool radius into account in the programming. If it is software programming, it may be caused by the centering of the selected tool rather than tangency. These two programming methods will lead to the workpiece over cut.

There is also a fault in the selection of cutting tools. For example, a milling cutter with a diameter of 16mm is used in the program, but a milling cutter with a diameter of 20mm is used. Although the difference of 4mm is not large with the naked eye, all the machined parts will be smaller. This requires that you carefully check whether the tool diameter is reasonable before processing, and do not take chances.
Another reason for over cutting of workpieces is the input error of workpiece coordinate system when zeroing. Remember to offset the radius value of a zero bar. The input error of tool compensation, tool length and tool radius compensation must be input correctly. If the input length of tool length is 0.5mm, the workpieces will be 0.5mm longer. Large workpieces cannot be used directly. Whether the tool radius compensation is positive or negative should also be considered before machining, If the tool is not directly cut, the workpiece will be over cut.

The above are the reasons for over cutting of several common machining parts. Other reasons include looseness of the spindle and low precision of the ball screw, which will cause over cutting in the machining process. After over cutting, check the reasons in time to prevent similar situations from happening again.