Checking Tooth Contact Pattern

Sparingly paint eight or ten of the drive gear teeth with a stiff mixture of engineers blue. Move the painted gear teeth in mesh with the pinion until a good impression of the total contact is obtained. The result should conform with the ideal tooth contact pattern (Fig.1).

The HEEL (A) is the larger outer end of the tooth.
The TOE (B) is the small or inner end of the tooth.
The DRIVE side (C) of the drive gear tooth is convex.
The COAST side (D) of the drive gear tooth is concave.

Fig.1:

Fig. 1 Ideal tooth contact pattern.

Fig.2:

Fig. 2 High tooth contact pattern.

Fig.4:

Fig. 3 Low tooth contact pattern.

Fig.3:

Fig. 4 Toe contact pattern.

Fig.5:

Fig. 5 Heel contact pattern.