Expert: Martin Meyer - 12/28/2009

Question
QUESTION: I have received a Waltham 31 day chim clock made in Korea. It keeps time, and chimes. My question is this at half past each hour it chimes the same as the top of the hour. I thought at half past each hour it would or should only chime once. I don't see any adjustment to the clock without taking the face off. I do not want to do that unless I have too. I did not receive a manual with this wall clock.

ANSWER: Hi Chris,

This is not an adjustment that you should try to make yourself. There is a fairly complicated series of levers and other parts which accomplishes the striking. I have attached a photo to help illustrate. The center shaft assembly, which the hands are mounted on, has at its base a two-pointed star-shaped piece (not visible). One of the points is longer than the other. When the clock strikes the hour, the long point lifts the rack and snail mechanism so that the rack tail falls to the correct step on the snail for that hour. On the half hour, the shorter point lifts the mechanism just high enough to strike one time; the rack tail does not drop onto the snail. In your case, one of the parts in this series is slightly out of adjustment, causing the rack tail to drop all the way to the snail even on the half hour. Determining which part to adjust can be very difficult; adjusting one part throws all the other parts out of adjustment, and the adjustment ranges are in the thousandth's of an inch. A qualified clock repairer can make this adjustment, although be prepared for many clock repairers to be reluctant to work on 31-Day movements.  http://www.clockmasteronline.com

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QUESTION: Due to that difficult task, is there a way to just disconnect the chime?

Answer
Hi Chris,

You can just let the strike (left key) run down until it stops, but this can occasionally cause problems and stop the clock.

The only safe and reliable way of disabling the strike train is to wind the mainspring fully, then attach a wire from one of the highest gears on the left (as you look at the clock) to a non-moving part of one of the main plates. This is a fairly delicate procedure, and I don't necessarily recommend that you try it yourself.  http://www.clockmasteronline.com