Adjustment Error and Measurement Error of CNC Machining

Adjustment error  

Inevery process of machining, some adjustment or other is made to the processsystem. Because the adjustment cannot be absolutely accurate, theadjustment error occurs.   In the process system, the accuracy of theposition of the workpiece and the tool on the machine tool is guaranteed byadjusting the machine tool, the tool, the fixture or the workpiece.   Whenthe original precision of machine tool, cutting tool, fixture and workpieceblank all meet the technological requirements without considering the dynamicfactors, the adjustment error plays a decisive role in machining error.  

The geometric error of the tool  

Anytool in the process of cutting will inevitably produce wear, and the resultingsize and shape of the workpiece changes.   The influence of toolgeometric error on machining error varies with different kinds of tools: whenusing fixed-size cutting tools, the manufacturing error of the tool willdirectly affect the machining accuracy of the workpiece;   However,for the general tool (such as turning tool), the manufacturing error has nodirect effect on the machining error.  

The geometric error of the fixture  

Thefunction of the fixture is to make the workpiece equivalent to the cutting tooland machine tool have the correct position, so the geometric error of thefixture has a great impact on the machining error (especially the positionerror).  

Measurement error

Whenthe parts are measured during or after machining, the measurement method, theaccuracy of the measuring tool, the workpiece and the subjective and objectivefactors all directly affect the measurement accuracy.  

Abovesix machining error can be avoided to a certain extent, so the need formachining operators during processing of the six easy machining error caused bymachining process can be more careful of the reentry after testing and thevalidation of the machining operation, so it can better reduce the effects ofmachining error.