Analysis on the causes of excessive size error of cutting parts
reasons for inaccurate size of workpiece cut by CNC cutting machine:
1 Programming software error
if the programming software has defects or has no cumulative error correction effect, it will form errors in the generated NC code. For example, the generated code size data is wrong or the compensation direction is wrong; Maybe there is cumulative error in the code, resulting in no issue in the size of small areas, and there are large errors in many line segments, forming a scene of dislocation in the introduction and extraction of entry points, which will also form the deviation of workpiece spacing during full board nesting. It is easy to check the program problem. Just convert the NC code into CAD graphics for measurement. These operations are essential. The compensation direction can be seen whether it is correct through simulation
2. CNC cutting machine accuracy
CNC cutting machine accuracy includes mechanical accuracy and electronic accuracy. The mechanical accuracy is mainly affected by the parallelism, straightness and degree of guide rail, the transmission accuracy of gear or steel belt, and the degree of cutting platform also affects the accuracy of workpiece
electronic accuracy is affected by numerical control software and motion control card, pulse equivalent, servo and various material servo drives in the development of materials. In particular, if the pulse equivalent is not adjusted accurately, it will form the issue of cutting circle and large part size
it is also easy to check the accuracy of the cutting machine. Just install a scoring needle on the cutting gun and run the program of correcting the error of the cutting machine to carry out scoring inspection
3. Graphic size error
there can be graphic size errors caused by neglect in the process of drawing or nesting. At this time, the reason can be found out by checking the size
4. Deformation during cutting of CNC cutting machine
deformation mainly includes thermal deformation and deformation caused by gravity. Reasonable lead position and cutting direction can reduce deformation during programming. Some cooling devices can be added as needed, and a cutting platform with reasonable structure can be adopted
5. Error caused by common edge
if common edge is used as the leading edge in the current market, the compensation amount, the actual slit width and the spacing at the common edge of the workpiece must be consistent. If inconsistent, the workpiece size will be larger and smaller
6. Randomness: the cutting machine runs disorderly
voltage fluctuation, loose data line, poor contact between the system and servo control line, loss of servo feedback signal, instability of servo drive circuit, etc. may cause the irregular running of the cutting machine
7. Cutting nozzle quality and slotting compensation
the quality of the cutting nozzle will affect the surface quality of the workpiece and the flatness of the cutting side. The slotting compensation must be consistent with the actual slotting width. The way to reduce this kind of error is to select a cutting nozzle with qualified quality, and the specification of the cutting nozzle should also be suitable for the thickness and material of the plate to be cut. At this time, the jaw waste should be replaced for trial cutting and adjustment until the kerf is uniform and the section is flat without slag, and then cut a rectangular shape to a certain size without compensation. Finally, measure it, and make up as much as the kerf width is smaller. (end)
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