The cause of undercutting: When the intersection of the tool tip line and the meshing line exceeds the meshing limit point N1, and the tool continues to move from position II, it will cut away a portion of the involute tooth profile that has already been cut at the root.
Consequences of undercutting: Gears with severe undercutting have, on the one hand, weakened the bending strength of the gear teeth; on the other hand, they will reduce the engagement of the gear transmission, which is very detrimental to the transmission. Causes of undercutting: When the intersection of the cutter's tooth tip line and the line of action exceeds the engagement limit point N1, as the cutter continues to move from position II, it will cut away a portion of the involute tooth profile already cut at the root.