Analysis of Machining Error in Face Milling

Summary

A face milling machine is used to make a wide plane accurately, however, it is usually difficult to obtain a good plane because of the presence of stair between neighbouring cutter passes and of the tendency of concavity even in one cutter pass. The study aims at evaluating such machining errors in face milling.

The analysis was made, considering that the deformation of a machine tool due to the cutting force and the thermal expansion of tool cause machining errors mainly. Predicted values of machining errors from data about the machine tool structure and the cutting condition correspond to measured ones in cutting experiments quantitatively.

As a result it becomes apparent that the obliquity of a cutter axis owing to the deformation of the machine tool structure by the cutting force causes the concavity of a plane , and that the change of cut of depth due to the thermal expansion of tool shapes stairs between neighbouring passes.