1, Different processing purposes
The main purpose of CNC rough machining is to quickly remove a large amount of material from the workpiece, laying the foundation for the subsequent precision machining stage. At this stage, processing efficiency is the primary consideration, while surface quality is not the focus. Rough machining uses larger cutting tools, higher feed rates, and cutting depths to quickly remove excess material from the workpiece, bringing it closer to its final shape. The processing results at this stage are usually rough on the surface, with lower requirements for dimensional accuracy and tolerance.
In contrast, the main purpose of CNC precision machining is to improve the surface smoothness, dimensional accuracy, and tolerance level of parts. At this stage, processing quality becomes the primary consideration factor. Precision machining uses smaller cutting tools, lower feed rates, and cutting depths to achieve a smooth and even surface of the part through a precise cutting process, while ensuring dimensional accuracy and tolerance requirements.
2, Differences in process characteristics
There are significant differences in the process characteristics between CNC rough machining and precision machining. Rough machining usually uses larger cutting tools to process at a faster speed and deeper cutting depth, which can quickly remove a large amount of material and improve machining efficiency. At the same time, the cutting force and heat generated during rough machining process are relatively large, which requires high tolerance for machine tools and cutting tools.
Precision machining, on the other hand, uses smaller cutting tools to process at a slower speed and shallower cutting depth. This can ensure the smoothness and dimensional accuracy of the part surface, while reducing the generation of cutting force and heat, protecting the accuracy and lifespan of the machine tool and cutting tools.
3, Differences in tool selection
In CNC machining, the selection of cutting tools has a crucial impact on machining quality and efficiency. There are also significant differences in tool selection between rough machining and precision machining.
Rough machining usually selects tools with larger diameters and stronger cutting capabilities, such as large-diameter end mills, face mills, etc. These cutting tools can quickly remove a large amount of material and improve machining efficiency. Meanwhile, the cutting edge of rough machining tools is usually blunt to reduce friction and heat generation during the cutting process.
For precision machining, tools with smaller diameters and higher precision are chosen, such as small-diameter ball end mills, end mills, etc. These cutting tools can ensure the smoothness and dimensional accuracy of the surface of the parts. At the same time, the cutting edge of precision machining tools is usually sharp to reduce cutting force and heat generation during the cutting process, and improve machining quality.
4, Different cutting parameters
Cutting parameters are important parameters in the CNC machining process, including feed rate, cutting depth, cutting speed, etc. There are also significant differences in the selection of cutting parameters between rough machining and precision machining.
Rough machining usually uses higher feed rates and cutting depths to quickly remove large amounts of material. At the same time, the cutting speed of rough machining is usually higher to improve machining efficiency. However, higher cutting parameters can lead to an increase in cutting force and heat, requiring higher tolerance for machine tools and cutting tools.
And precision machining uses lower feed rates and cutting depths to ensure the smoothness and dimensional accuracy of the part surface. Meanwhile, the cutting speed of precision machining is usually lower to reduce the generation of cutting force and heat. This can protect the accuracy and lifespan of machine tools and cutting tools, while improving machining quality.
5, Differences in surface quality
There is also a significant difference in surface quality between CNC rough machining and precision machining. The surface of the parts after rough machining is usually rough, with large peaks and valleys, and lower requirements for dimensional accuracy and tolerance. This is because the main purpose of rough machining is to quickly remove material, rather than improve surface quality.
The surface of the precision machined parts is very smooth and flat, with high requirements for dimensional accuracy and tolerance. This is because the main purpose of precision machining is to improve the surface smoothness and dimensional accuracy of the parts. Through a precise cutting process, precision machining can eliminate the peaks and valleys left by rough machining, resulting in a smooth and even surface of the part.
