Usually +- 10 to 15 seconds/day is good four mechanical regulation...depends how much time and finicky you are about accuracy. Using a toothpick method of back and forth, you can get pretty accurate. And then if you really want to regulate it, you take 3 to 5 reading on watch positioning and on the wrist over time and average the readings out! haha! My friend made his own mechanical regulator using a graded rod/screw-in system....he can split seconds in regulating the tweaking! He got his orange monster to 3 seconds/day.... :thumbup: