Hermle Clock Pendulum Measuring
Hermle Clock Pendulum Measuring is done in combination of the CM number and the pendulum bob diameter. The CM will only be accurate to the pendulum length if the pendulum bob is small. If it has a larger bob it will be a longer pendulum. The larger the bob, or the heavier the pendulum, the longer it needs to be. Best to email [email protected] if you need the exact info on how long your pendulum should be. We would need the CM number off the back plate, and also how wide the pendulum bob is (round disk at the bottom of the pendulum).
The pendulum length (**cm) will be from the suspension post all the way down to the bottom of the pendulum nut threads. The length includes the pendulum from tip to tip, the leader it hangs on, and the suspension spring. This pendulum length will not always be exactly what is marked on the movement. There are other factors such as the pendulum bob diameter. The larger the pendulum bob diameter then the longer the pendulum length despite the CM length.
If the CM length on the old unit matches the CM length on the new unit, this is all that is needed. Sometimes it is required to use the old leader and put it on the new unit. If both CM numbers match and there is still a timing issue, it may had the wrong pendulum. The next question would be, did the clock ever keep time with the pendulum it had?