The dimensions of the main specifications of CNC machine tools should be adapted to the contour dimensions of the workpiece. That is, small workpieces should be machined with small specifications, while large workpieces should be machined with large specifications to achieve reasonable use of the equipment.

When choosing a CNC machine, you should generally consider the following aspects:

1. The size of the main specifications of the CNC machine tool should be compatible with the contour size of the workpiece. That is, small workpieces should be machined with small specifications, while large workpieces should be machined with large specifications to achieve reasonable use of the equipment.

2. The machine structure depends on factors such as the size of the machine tool and the weight of the machined workpiece.

3. The working accuracy of the machine tool is compatible with the machining accuracy required by the process. According to the machining accuracy requirements of the parts, the machine tool should be selected. For rough machining processes with low precision requirements, machine tools with low precision should be selected. For precision machining processes with high precision requirements, high precision machine tools should be selected.

4. The power and stiffness of the machine tool and the range of maneuver should be adapted to the nature of the process and the most appropriate amount of cutting. If the blank is removed by the roughing process and the cutting allowance is selected, the machine tool requires large power and good rigidity.

5. Convenient clamping and simple fixture structure is also a factor to consider when selecting CNC equipment. The choice of horizontal CNC machine tools or vertical CNC machine tools will directly affect the structure and machining coordinate system of the selected fixture, which is directly related to the difficulty of CNC programming and the reliability of CNC machining.

It should be noted that when selecting a CNC machine tool, the function of the numerical control equipment should be fully utilized, and reasonable development should be carried out according to the needs to expand the functions of the numerical control machine tool to meet the needs of the product. Then, according to the selected CNC machine tool, the CNC machining plan and process route are further optimized, and the content of the process is appropriately adjusted as needed.

When selecting a machine tool, first of all, to ensure the technical requirements of the machined parts, it is possible to process qualified parts. Secondly, it is beneficial to improve production efficiency and reduce production costs. The choice of a machine tool generally takes into account the machine structure, load, power, stroke and accuracy. According to the material state, technical state requirements and process complexity of the machined parts, appropriate and economical CNC machine tools should be selected to take into account the following factors.

1. The type of machine tool (car, milling, machining center, etc.), specifications (stroke range), performance (processed materials).

2. The spindle power, torque, speed range, tool and tool system configuration of CNC machine tools.

3. Positioning accuracy and repeat positioning accuracy of CNC machine tools.

4. Positioning reference and clamping method of parts.

5. The linkage between the machine coordinate system and the coordinate axis.

6. Control system tool parameter settings, including machine tool setting, tool compensation and ATC and other related functions.