Progressive Strategy of Milling by means of Tool Axis Inclination Angle

This work deals with problems of tool axis inclination angles in ball-end milling. Tool axis inclination angle contributes to improvement of functional surface properties (surface integrity surface roughness, residual stress, micro hardness, etc.), decreasing cutting forces and improving production. By milling with ball-end milling tool, using standard way of cutting, when work piece and cutting tool contain right angle, we have zero cutting speed on edge. At this point cutting tool only pushes material into the work piece. Here we can observe the following undesirable effects chip contraction, increasing of cutting temperature, increasing vibrations or creation of built-up edge. These effects have negative results – low quality of surface and decreasing of tool life (in the worse case even it is pinching out). These effects can be eliminated with the tilt of cutting tool or tilt of work piece. Keywords—CAD/CAM system, tool axis inclination angle, ballend milling, surface roughness, cutting forces. I. MILLING BY MEANS OF THE TOLL AXIS INCLINATION ANGLE Thanks to tilt of cutting tool we can change effective diameter of cutting tool and with it also effective cutting speed. Effective tool diameter (without tilt of cutting tool) can be calculated according to this mathematical expression: ( ) a d 2 p p eff a d ⋅ = [mm] (1) Where: ap axial depth of cut [mm], d tool diameter [mm], deff effective tool diameter [mm]. Effective diameter of pulled cutting tool is calculated according to this mathematical expression [2]: