The Importance of Including Size Effect When Modeling Slot Milling

Abstract

This paper presents a detailed mechanistic force analysis that includes size effect for slot milling operations. Existing studies of the milling process have modeled the slot end milling operation as a simple geometric extension of peripheral end milling models with constant values for the specific energies used to predict forces for a given cutter geometry and cutting conditions. This paper addresses the limitations of this approach for accurate predictions of the instantaneous cutting force variation, particularly for steady-state slotting with four-flute cutters. It is shown through a comparison of model simulations and experimental results that significantly improved predictions of the cutting force variation are obtained by properly accounting for the size effect in slotting. The dependence of the cutting force variation on axial depth of cut and helix angle is demonstrated. Practical implications of selecting helix angle and axial depth of cut based on the improved slot end milling model are also discussed. Modeling approaches other than the mechanistic approach considered here are also noted in this light.

An experimental investigation of micro-machinability of copper 101 using tungsten carbide micro-endmills

“…The size effect causes the specific energy of the workpiece material to increase significantly at small uncut chip thicknesses. Causes of the size effect include ploughing of material due to large negative effective rake angles, the pressure applied to the flank face of the tool due to elastic recovery of the material, and strain-rate dependency and dislocation density/availability [20,[27][28][29][30].…”

Improved dynamic cutting force model in peripheral milling. Part II: experimental verification and prediction

“…Studies on theoretical modelling and experimental verification of dynamic cutting forces in peripheral milling have been investigated [2][3][4][5][6][7][8] and have been reviewed by Smith and Tlusty [9]. Very few researchers working on the cutting force models have focused their attention on the following experimental issues, i.e., the unavoidable cutter run-out and vibrations between the cutter and workpiece in the cutting process, as well as the successive inconsistency of measured cutting forces [10,11]. Some researchers attempted to address the cutter run-out in their work [5][6][7], however, no attention was given to cutting force models, especially experimental verification of the models.…”

Research on the design and manufacturing of an outer cycloid slotting cutter

“…Although the outer cycloid gear is very sensitive to variations in centre distance, it is still widely used. The slotting cutter used in the manufacture of this kind of gear, together with precise design and manufacturing models, are discussed in references [1][2][3][4]. Using the involute slotting cutter given in references [5,6], references [7,8] provide the general mathematical CAD/CAM models of the slotting cutter, the grinding wheel and the qualified length of tooth.…”

“…Differential of x 1 , y 1 x 2 , y 2 Coordinate of outer cycloid x 2 , y 2 Differential of x 2 , y 2 x * , y * , z * Coordinate of generated cylinder surface; coordinate of rake face Z 0 Number of gear α…”