Today I fixed a grandfather clock movement, for the second time. I thought this would be a good place to record it.
The first time I fixed the clock was 5 years ago- the clock had been in storage and was not functional. The symptom was that the pendulum would slow to a stop some time after being started. The solution was in the weights- there are two weights for chimes that are each 5 lbs, and a center weight that is 7 lbs. Once the 7 lb. weight was in the correct position to drive the clock movement, the pendulum and clock began to work properly.
The second instance I fixed the clock had the same symptom: the pendulum would slow to a stop soon after being started (1-5 minutes). In the second instance the fix was not as simple. The problem was caused by the 'beat' of the clock. The beat is the sound of the tic and the tock. A proper clock should have a tick and a tock spaced equally apart in time. If not, a 'beat' can be heard- the tick and the tock are too close together followed by a silence that is too long.
To diagnose the beat and repair it, I used these instructions:
http://ticktocktony.com/Clock-Repair-How-To-Articles/how-to-adjust-a-clock.html
In short: put tape behind the pendulum, move it left and put a line on the tape where the tic sound is heard. then move the pendulum right and put a line where the tock sound is heard. Finally mark the center hanging position of the pendulum. The tick and tock marks should be equidistant from the center mark- if not, there is a beat. This can be adjusted by bending the 'crutch'- the metal rod that runs down from the clock movement gear wheel to the pendulum itself. However, in the case of this clock, I adjusted the beat by unscrewing a set screw on the escapement (http://en.wikipedia.org/wiki/Escapement)
I will try and post photos later as I acquire them.
