That's not how standard punctuation in the English language works. A period is not just a slightly longer pause than a comma. A comma is used to separate different parts of the same thought. A period is used to separate different thoughts. If there were a comma, it would be ambiguous whether "fine detail" and "moving parts" were meant to describe the same thing. As it is, there's nothing at all to suggest that the sentence about moving parts is meant to modify the definition of "fine detail" in any way.