Characteristics of Cutting Force in Plain Milling Operation Using a Helical Cutter

Abstract

A unique optical method is developed in order to measure the cutting force. The variation of the horizontal component of cutting force in the direction of feed, the vertical component which acts vertically to the arbor and the axial component are precisely measured corresponding to a variation of the undeformed chip thickness. Characteristics of the cutting force and influences of the helix angle are compared and discussed both for up and down milling, and also on the basis of the force variation ratio proposed. The cutting force component and the thrust force component are derived, and the normal and frictional force on tool rake face, the apparent friction angle and the chip flow direction are also obtained. The mechanics of the milling process is discussed basing upon the experimental results. The role of the helix angle is experimentally clarified and the concept of the effective rake angle is criticized.