Timing a mechanical pendulum clock
Fine timing the clock
If the clock is timing slow, raise the pendulum bob by turning the nut at the bottom of the bob. If the clock is fast, do the same but lower the clock's pendulum bob instead. One full turn is somewhere around 1-2 minutes a day faster or slower.
If there is no more adjustmentIf the bob is all the way up and its still too slow or fast, shorten either the pendulum or the leader it hangs on to correct.
It is possible to shorten or lengthen the pendulum leader to put the clock in time range with some solder if needed. 1 3/4 inches is a good measurement to make one of these longer or shorter as needed, as this is the length of the threads at the bottom of the bob.
So it will give a full timing adjustment range all over again and can go up or down as needed.
German pendulum length CM stamp
The pendulum length is overall and not just the pendulum itself. These German units measure there pendulum lengths from the top of the movement and all the way down. This will include the suspension spring, the leader and also the pendulum itself.
Used to keep time, now does not
If the clock kept time in the past but now does not, it means a worn gear. The escape wheel is worn and it is advancing more than one tooth at a time.
The escape wheel alone would be hard to find, and hard to replace both. The entire movement would be disassembled to replace this worn escape wheel if there is another one found that will work.
The price would be about the same for a complete overhaul or a brand new one. First see if the clock movement is in production and available new. We do this by getting the numbers off of the back plate of the movement itself, right off of the brass. Please email and we will check the availability and quote for the new one.
Mechanical Pendulum Clock Timing Issues - Conclusion
Fine timing of the clock is easy as seen. If the clock kept time in the past and now too fast, its time for a new movement and has nothing to do with the pendulum. A worn escape wheel is most likely the cause and a new unit would be less cost then a repair.
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