Film Lapping Device

A film lapping device for lapping a tooth surface of a gear-shaped workpiece with a lapping film, comprising:

• a workpiece holder, with which the workpiece is rotatably held;
• a gear-shaped backup tool that meshes with the workpiece with the lapping film interposed therebetween;
• a supply reel that feeds the lapping film to the backup tool;
• a take-up reel that collects the lapping film from the backup tool;
• a slide table on which the backup tool, the supply reel, and the take-up reel are mounted;
• a slide motor that moves the slide table in a direction toward or away from the workpiece holder;
• a tension sensor that detects tension of the lapping film;
• and
• a controller including circuitry that operates the slide motor to move the slide table toward the work piece holder and determines that the backup tool and the workpiece are meshed when the tension sensor detects an increase in the tension of the lapping film.