【Wisdom of Gears】 Inspection of gear tooth contact pattern

The inspection of gear tooth contact pattern is, put paint material on gear tooth of gear and pinion then to mesh and rotate gear pair.
After rotation, contacted paint material on gear tooth become removed.
This removed contact, we call it gear tooth contact pattern and evaluate contact dimention and position or shape.
Measure the gap between gear and pinion by dial gauge, it's so-called "backlash".
Make pinion not to rotate, and then to measure the backlash at tooth surface of gear side.