What are the common errors of CNC milling parts?

Although CNC milling machine has the advantages of strong adaptability, high machining accuracy, stable machining quality and high production efficiency, there are still some common errors of CNC milling parts.

Here is the content list:

l The processing plane is not smooth

l The tool mark on the side of finishing milling is too obvious

l Tool change trace in finish milling

l After finishing, burr or batch edge will be left on the surface or side

l Finish machining of special shape workpiece

The processing plane is not smooth

In the parts processing of CNC milling machine, the surface finishing is an important process, and it is also a frequent process, which requires high surface quality. But in the actual processing, sometimes you will get an uneven and smooth plane, which does not meet the requirements.

The main reason for this problem is that the performance of the cutting oil can not meet the processing requirements in finishing when the tool feed speed is too fast, and the vibration caused by the rapid movement of the tool is easy to leave an uneven path to the processing surface. Sometimes there is a certain difference between two adjacent tool paths, which is caused by the inconsistent cutting direction of the tool. To avoid this problem, we should adopt the full milling processing method and select the special cutting oil.

The tool mark on the side of finishing milling is too obvious

In the CNC milling machine workpiece processing, almost every workpiece will be required to finish milling side, and many times there will be the problem that the tool trace on the side of finish milling is too obvious, this is not allowed, it will seriously affect the appearance of the workpiece.

The main reason for this problem is the improper selection of the position and parameters of the tool advance and retraction, and the milling methods provided by different processing software will also be different, but both will provide the selection of the depth of the tool and the parameter selection of the tool in and out. In addition, when using non-special cutting oil, due to the insufficient extreme pressure and anti-wear performance, the oil film breaks instantly in the processing process, resulting in scratches on the workpiece. In order to avoid the above problems, we can make relevant adjustments from four aspects. The first is to select the feed point correctly, the second is to add an overlap when cutting in the middle, the third is to use full-depth cutting when finishing the side, and the fourth is to use special cutting oil when finishing.

Tool change trace in finish milling

In ordinary machining and high-speed machining, tool replacement is needed. If you do not pay attention to the relevant adjustment of the parameters during the tool replacement operation, obvious traces will appear, which will seriously affect the appearance of the workpiece.

In the bottom or side of the finish milling, the appearance of tool marks is a common phenomenon, many times people will think that this is an unavoidable error this is completely avoidable. In order to solve this problem, in the processing of the workpiece, the finishing of the concave corner needs to replace the small tool. Because of the force and swing in the process of processing, it is easy to produce the trace of tool receiving at the corner.

After finishing, burr or batch edge will be left on the surface or side

Modern workpiece processing has higher and higher requirements for the surface, and the appearance of a burr or batch edge is also unacceptable. If the workpiece is corrected with a file, it will also affect the accuracy and size of the workpiece, etc. to achieve direct use after milling, there is no need for later grinding. But in the actual production, there are still a lot of burrs and batch front.

To solve this problem, we must pay great attention to the use of cutting tools, and use special tools to ensure sharp cutting. In addition, we should also do a good job in the planning of the tool path, and increase the secondary polishing tool path, that is, the first process the surface, then process the side, and then process the surface, so as to ensure that there is no burr and batch edge, which is very useful for workpieces that cannot be polished.

Finish machining of special shape workpiece

For some special shape workpiece finishing, the software usually has a fitting error, sometimes if the calculation error is too large, it will cause the deformation of the workpiece, affect the appearance. To solve this problem, we must start with the software and control the error. This value is relatively reasonable, which will not affect the speed of calculation and will not cause deformation to the workpiece.

In the process of CNC milling, safety should always be put in the first place, and the safety operation rules of CNC milling should be observed to avoid machining errors.