Page 318 - Gear Technology Solutions

Figure 14: Blade failure “Banana Peel”

The definition of a positive, neutral and negative side rake angle is visualized
in Figure 15. A positive side rake angle makes the blade appear sharp in the
cut. A negative side rake angle results in a dull blade. A more precise definition
of the effective rake angle or “sharpness” of cutting edge, blade tip and clear-
ance edge can be found in Figure 16. The predicted chip flow direction from
the cutting edge onto the front face is defined as FA. If FA is projected to the
cutting plane (FAproj), then the angle gp between FA and FAproj is the rake angle
relevant to the chip removing mechanics. It is called the “Effective Normal
Rake Angle”.

Figure 15: Side rake angles, positive at top, neutral in center,
negative at bottom

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