Things You'll Need
Instructions
Wind up your mechanical watch and set it aside for 24 hours to determine how much time it is losing. Time it against a quartz watch or clock. If the watch loses or gains less than eight seconds in 24 hours don't bother regulating it. If it gains or loses several minutes, there is something wrong with the movement and regulating it won't solve the problem. Take it to a watchmaker for repairs.
Place the watch on a table before you decide to open it for adjustment. Gravity and position play a role in the accuracy of a mechanical watch. According to Rolex, the watch may gain a few seconds if you lay it face up and running for 24 hours. It will lose a few seconds if the watch is set on its side with the crown (winding knob) facing downward. It will lose more seconds if the watch is set on its side with the crown facing up.
Use a case blade to open a snapdown case back of a mechanical watch if your positioning experiment does not work. Use a watchmaker's rubber ball, a wadded up ball of duct tape or rubberized jar opener to twist off counterclockwise a screwdown case back.
Place the watch face down on a clean, flat surface. Use a jeweler's loupe or magnifying glass to find the regulator. The regulator will be a notch next to the balance wheel with a "+" and "- " on either side. Most watches, however, have a thin bar between the "+" and "-". Many luxury watches don't have regulators and must be serviced by a watchmaker.
Step 5
Use a toothpick or similar clean tool and move the bar a tiny fraction towards the "+" to make the movement gain time or towards "- " to slow it down. Use a screwdriver if the regular is a notch.
Set the watch aside for two hours and time it again to determine the gain/loss of seconds. Keep the case back off. Record the gain/loss and multiply it by 12 to determine how many seconds are gained or lost in 24 hours. Continue making incremental adjustments until the gain/loss is less than eight seconds. Your final adjustment should be made only within 60 to 120 seconds .