Addendum modification coeff.

Gears can be designed and finished with an addendum modification, which changes the shape of the tooth flank in order to influence the properties of the gear.

The addendum modification x * m_n is the deeper or less deep path created by the tool in millimeters.

For more information, see DIN 3960:1987, section3.5.4.

The addendum modification factor can be specified in various ways, or results from:

• Specification of the value for the gear and pinion in the Editor (see sub-item "determining the addendum modification")
• Specification of the sum of addendum modifications (directly, or using the main geometry values and the center distance) + Specification of the distribution of the sum of addendum modifications

The corresponding gear center distances or the addendum modification coefficients of the finished teeth can be specified as an alternative to specifying the addendum modification coefficients.

Positive addendum modification:

Profile reference line shifted from the reference circle in the direction of the tip circle.

Negative addendum modification:

Profile reference line shifted from the reference circle in the direction of the root circle.

Effects of positive addendum modification:

• Undercut is reduced or eliminated
• Minimum number of teeth is reduced
• Tooth root becomes thicker
• Tooth root fillet radius is reduced

Negative addendum modifications lead to the opposite results.