Question

5. Sketch two views of a turning operation to show that the back rake angle and
the side rake angle correspond to the inclination angle and the effective rake
angle, respectively.

Answer 1

In case of oblique cutting, which is practically more common, the actual direction of chip flow and the corresponding rake angle, i.e., effective rake should be used for more reasonably accurate analysis and assessment of cutting forces, friction and tool wear.  

Effects of oblique cutting

• In contrary to simpler orthogonal cutting, oblique cutting causes the following effects on chip formation and mechanics of machining:
• Chip does not flow along the orthogonal plane; Positive ? causes V
• reduction of mechanical strength of the tool tip
• increase in temperature at the tool tip
• more vibration in turning slender rods due to increase in PY (transverse force)