How to Adjust a Miller Clock Pendulum

As the need arises, a Howard Miller clock may require adjustments to increase the accuracy of its timekeeping. Weight-driven Miller clocks use a pendulum to regulate the time. A disk, often referred to as a “bob,” is attached to the pendulum. Raising or lowering the disk alters the speed of the clock mechanism, which causes the indicated time to run faster or slower. You can adjust the Miller clock pendulum with basic do-it-yourself skills.

Instructions

1. Check the time on the Miller clock to determine if the adjustment is intended to speed up the clock or slow it down.

2. Open the door of the Miller clock to reach the pendulum.

3. Stop the motion of the pendulum by catching the disk at the peak of its arc on either end of the swing. Release it at its center position.

4. Locate the adjustment nut at the bottom of the pendulum disk.

5. Turn the adjustment nut clockwise to increase the speed of the clock and counterclockwise to decrease speed. One full turn in either direction changes the timekeeping by 30 seconds within a 24 hour period.

6. Set the correct time. Check the time in 24 hours and adjust further, if necessary, by repeating Step 4.

Tips & Warnings

• Wear gloves or use a clean soft cloth when handling brass clock parts.

References

• Howard Miller: Customer Help Center
• The Clock Depot: Grandfather Clock Owners and Setup Guide