Ring gear backlash question

[handcannon]

I'm okay with what pin head said. Going way back to the early seventies doing a tool and die apprenticeship the guideline was just as pin head said, however, you perform the task not straight back and forth or sideways but rather in a figure eight pattern. This action tends to mediate pressure differences your hand applies to the part helping to keep from removing more material from one edge than the other. Measuring frequently is the key.

Interesting reason. That's the same pattern I learned for sharpening a chisel. But the reason was to keep the stone flatter than with a straight back and forth motion.

Don