Kent
09-23-2003, 02:30 AM
Hi Chris:
There a few reasons why a watch that runs fine lying on its back will run fast when hanging from a hook. The first is the if the watch is hanging free, otherwise unsupported, some of the energy in the balance wheel will be lost in causing the movement to swing back and forth. Since the rate of oscillation of the balance wheel regulates the timekeeping rate of the watch, allowing the balance wheel to lose energy to start and maintain the watch swinging will change the timekeeping rate of the watch.
To prevent this I've added two support tabs to the watch stand that is used for my watch at night. This is shown in the right-hand side of the picture whose link is below. Notice that there are soft pads (small electrical wire insulation) slipped over the ends of the brass wire tabs, to protect the watch case.
Another reason is that your watch may not be adjusted to minimize the error between different positions. Such watches, built after 1907, are usually marked "Adjusted 5 Positions." Even if your watch was built and adjusted to five positions, there no guarantee that the adjustment hasn't been upset in the intervening 70 or 100 years. In fact, it most likely was upset.
The error caused by difference between the watch lying on its back and being vertical is one of the hardest to eliminate. When vertical, the friction on the balance staff is that of the two staff pivots rotating in their hole jewels. When the watch is lying on its back, the friction on the balance staff is only that of the bottom end of the lower pivot pressing against the lower cap jewel. Depending upon the shape of the pivot end, the friction, and hence the watch's timekeeping rate, can be significantly different. If this is the problem (and there may be others - such as a cracked jewel), the correction is in altering the shape of the pivot end.
Good luck,
Kent
That guy down in Georgia :smile:
There a few reasons why a watch that runs fine lying on its back will run fast when hanging from a hook. The first is the if the watch is hanging free, otherwise unsupported, some of the energy in the balance wheel will be lost in causing the movement to swing back and forth. Since the rate of oscillation of the balance wheel regulates the timekeeping rate of the watch, allowing the balance wheel to lose energy to start and maintain the watch swinging will change the timekeeping rate of the watch.
To prevent this I've added two support tabs to the watch stand that is used for my watch at night. This is shown in the right-hand side of the picture whose link is below. Notice that there are soft pads (small electrical wire insulation) slipped over the ends of the brass wire tabs, to protect the watch case.
Another reason is that your watch may not be adjusted to minimize the error between different positions. Such watches, built after 1907, are usually marked "Adjusted 5 Positions." Even if your watch was built and adjusted to five positions, there no guarantee that the adjustment hasn't been upset in the intervening 70 or 100 years. In fact, it most likely was upset.
The error caused by difference between the watch lying on its back and being vertical is one of the hardest to eliminate. When vertical, the friction on the balance staff is that of the two staff pivots rotating in their hole jewels. When the watch is lying on its back, the friction on the balance staff is only that of the bottom end of the lower pivot pressing against the lower cap jewel. Depending upon the shape of the pivot end, the friction, and hence the watch's timekeeping rate, can be significantly different. If this is the problem (and there may be others - such as a cracked jewel), the correction is in altering the shape of the pivot end.
Good luck,
Kent
That guy down in Georgia :smile: