1. How to adjust your cuckoo clock pendulum for accurate timekeeping. Every time your cuckoo (coo coo) clock pendulum makes a complete swing back and forth, one tooth of the time train is released from the escape wheel. Each time a tooth escapes, the time train advances, resulting in a slight movement of the minute hand. And the faster the pendulum swings, the faster the minute hand will turn. A basic principle of physics is that the length of a pendulum determines how fast it swings. A short pendulum swings faster than a long pendulum. You can change the effective length of the pendulum by raising or lowering the pendulum bob on the pendulum stick. If you push the bob up, the cuckoo will run faster. Lower it and the cuckoo will run slower. You can remember this principle with the phrase… A SHORT DOG’S TAIL WAGS FASTER! If your cuckoo runs too fast or slow, the best way to correct this problem is to set your cuckoo to an accurate watch or clock. After 24 hours, record how many minutes your cuckoo is running too fast or slow. Then adjust the bob up or down the pendulum stick to change the pendulms effective length. You’ll need to take an educated guess as to the distance. Reset the cuckoo minute hand time to your watch or clock again. Repeat this process every 24 hours, recording the results, and readjusting the bob until you are within 3 minutes of the correct time. Then, switch from recording every day to recording every week. Use the same process described, recording the time difference, adjusting the bob up or down every week, until the cuckoo is accurate within approximately 3 minutes per week. Remember, mechanical cuckoo clocks are not as accurate as quartz or electric clocks! A three minute error per week is not bad. Maybe you can do better. What you are attempting to do is to obtain is the best timekeeping possible from your cuckoo clock. Afterwards, you will still need to sychronize the cuckoo (coo coo) clock minute hand to an accurate clock or watch, each week or as desired.