Customer asks:I have a question regarding the positioning accuracy on the CNC machining center, that is I saw two exactly same machine. However, one position accuracy is 0.004mm, while the other one is 0.066mm. Does it means that the smaller the data of positioning accuracy, the higher the accuracy?

Answer: Normally people tend to think so. But we can not judge just from the data. Because in other situation, it is on the contrary. The bigger the data, the higher the accuracy. So when we are talking about machine accuracy, we need to make clear how it was defined. That is to understand that different machine has different standards and definition on accuracy. Accuracy means the ability of tool nose positioning to program target point. And there are many ways of measuring the positioning and what's more, different countries have different standards. For example, in Germany, they use VDI/DCQ3441. So when describe the machine accuracy, it would be necessary to specify the standard. The same machining center will has different data with different standard. It is easy for us to mix up that same index means different in differnt accuracy, while different index may have same meaning. The standards of machining center is calculated out by several measuring. The main differences are as below:

1. Number of target points

2. Number of rounds of measuring

3. Accuracy standards and ways of calculation

4. From one way or one-way near the target point