Would you please tell me the cause of a watch mainspring breaking shortly after cleaning the watch? In one watch I cleaned, the spring broke about two hours after assembly. I usually don't clean the spring, just put in fresh oil. This doesn't happen in very many watches and I thought perhaps the watch had been laid away wound tightly for some time before cleaning, causing it to break when put in use again.
Will you please give your opinion on this?
Answer: The exact cause of mainspring breakage is not definitely known. According to one theory it is due to minute imperfections in the steel itself which are introduced during manufacture. We do not believe that the process of cleaning had anything to do with the breaking of the spring. As a matter of fact, mainsprings often break in the packages before they are ever placed in watches.
May I submit a question to the Question Box? It concerns the mechanism of a sweep second wrist watch, the type which has a wheel placed above the train bridge, pressed onto a pivot of the third wheel and engages a pinion running through the center wheel staff. The question is, "By what procedure is this wheel removed when taking the watch apart for cleaning?"
Answer: In a factory, where just one type of movement is handled by an individual a special fixture would be used for this' purpose, but the repairer must be able to handle all makes of watches. A safe and simple method of removing the extra third wheel is to first take off the bridge and wheel. By holding the wheel with one hand and the regular third wheel with the other hand the two can be separated by gently twisting and pulling them apart.
The 992 Hamilton movement is designed so that the level of the hairspring is below the center wheel. In fact, unless a watch has been somehow mutilated it does not seem possible that anyone could alter this relation.