How to evaluate the quality of engraving and milling machine?

1. Processing accuracy: processing accuracy will directly affect the quality of the product, many people doubt the accuracy of the machine tool, will directly affect the buyer's decision. Attention should be paid to two different concepts of machining accuracy and machine tool accuracy, the positional accuracy on the manufacturer's samples or product certificates is regarded as the machining accuracy of the machine tool is wrong. The positional accuracy marked on the sample or certificate is the accuracy of the machine itself, while the machining accuracy is the sum of errors caused by various factors of the entire machining system, including the allowable error of the machine itself. In the selection process, the evaluation method of process capability KP can be referred to as the basis for accuracy selection. In general, the calculation should be greater than 1.33.

2. Stiffness: Because the stiffness of high-speed machining centers directly affects the productivity and machining accuracy of the machine tool, the machining speed of machining centers is much higher than that of ordinary machine tools, and the motor power is higher than that of ordinary machine tools. Machine tools have the same specifications, so the structural design of the stiffness is much higher than ordinary machine tools. Orders can be checked according to process requirements, allowable torque, power, axial force and maximum feed force. In order to obtain a high stiffness of the machine tool is often not limited to the size of the part, and choose the relative size of the machine tool parts greater than 1 to 2 specifications.

3. The number of axes and linkage axes: the number of coordinate axes and linkage axes should meet the typical workpiece processing requirements, the number of coordinate axes is also one of the signs of the machine tool level. In general, with the same manufacturer, the same specifications, the same precision machine tools, plus the standard coordinate axis, the cost increase of about 35%. Although increasing the number of axes can enhance the function of the machine tool, but we must pay attention to the technical requirements and capital balance.

4,. The choice of CNC system: CNC system is the core of high-speed engraving and milling machine operation. CNC functions are divided into basic functions and selective functions. Basic functions are provided when necessary, and the manufacturer provides selection functions only when the user chooses. The functions of a CNC machine must be selected according to the performance requirements of the machine. When ordering, we should not only fulfill the required functions, but also avoid the waste caused by low utilization. We should pay attention to the relationship between functions. Among the available CNC systems, the performance varies greatly. We should choose according to the needs rather than unilaterally pursuing high goals to avoid waste. When choosing multiple machines, we should choose the same manufacturer's CNC system as far as possible to facilitate operation, programming and maintenance.

5. Automatic tool changer and tool magazine capacity: the choice of automatic tool changer mainly consider the time and reliability of tool change. Short tool change time can improve productivity, but the tool change time is short. Tool change device structure is complex, high failure rate, high cost. According to statistics, about 50% of the machining center failure and automatic tool changer device. Therefore, under the premise of meeting the requirements of use, the automatic tool changer should be selected as far as possible with high reliability in order to reduce the failure rate and cost of the whole machine. The working quality of the automatic tool changer and the capacity of the tool magazine directly affect the performance and quality of the machining center. The capacity of the tool magazine is to meet the needs of the tool complex machining parts.