Setting Time: Grandfather Clock

Antique grandfather clocks need attention from time to time... no pun intended. Here are a few tips to adjust the time on your Antique Grandfather Clock.

If the clock is running to fast or too slow what you need to do is adjust your pendulum bob. That big round disk at the end of your pendulum is your pendulum bob. You adjust your pendulum bob with the nut located at the bottom of the bob. This is what adjusts the timing. If the bob is raised up this will make the clock run faster. If the bob is lowered this will make the clock run slower. You can expect to get this accurate to within one minute fast or slow per week. Better than that, consider yourself lucky.

Start by setting your grandfather clock to a standard electric or quartz clock or watch. Then check the time against the clock 24 hours later. If the clock is running fast, turn the nut to the left. If the clock is running slow, turn the nut to the right. Then reset the time on your clock and check it again in another 24 hours. Keep performing this process until the clock appears to be running on time. Expect to do this every week at least. Keep a record of the distance you turned the nut each time so you will have an idea of how much you’ll need to turn it in the future.

Eventually the timing will be accurate enough so that you’ll only have to check the clock once each week and it should never be off by more than a minute. Just a tip. Some grandfather clocks are made so that a full turn of the nut is actually equal to one minute. So if your clock is running 2 minutes fast then all you need to do is turn the nut two full turns to the left and this will set the timing correctly. Of course the only way to know if your clock is one of these is to test this theory out.

Some grandfather clocks actually have two nuts attached to the bottom of the pendulum. If your clock is one of these then most likely it is a very accurate clock. Many clock owners believe the bottom nut is a lock nut against the top nut. This is not true. Actually you must make sure that the bottom and top nuts do not touch. Let the top nut raise or lower the pendulum bob until you’ve gotten the timekeeping as accurate as possible. Then by either turning left or right use the weight of the top nut to make your final adjustments to your clock’s timing.