Because there inevitably remain some minor imperfections when all the parts have been attached, after assembly micro-adjustments must be made to correct any remaining flaws; at this point everything depends on the individual skill and experience of the craftsman.
因為零件在「拋光」之後，精準度多少會有些微的差距，組裝之後，如何將誤差微調回來，就有賴師傅的多年經驗。