Abstract: In the programming and operation of the numerical control miller, the relative position of the tool and its workpiece are very important.The main factors which influence the accuracy includes the length and the radius of the tool as well as the tool attrition.Different numerical control milling system has different means to deal with the problem.The causes for problems in cutting are analysed and some solutions are suggested based on different numerical control milling system.

Key words: milling, tool, compensation, numerical control system