Waltham running slow

[chaplin37]

I have a waltham mens wrist watch(I will post pictures later). The problem I have with it is that when i tested it, the minute hand only moves 15 minutes over 24 hours. This is what i have done with it so far, I’ve cleaned and oiled it, demagnatized it, Ive tried another set of hands to see if that was the problem, I’ve tried another cannon pinion, I also tried to tighten another cannon pinion for it. Ive hooked it up to my timing machine and it is running correctly. I’m stumped when it comes to this watch as to why it is running so slow. Ive also examed the gears to see if any of the teeth are broken and the gears look good. Thanks

[chris mabbott]

Does the hour hand move correctly?
Does the stem return to the wind position correctly?

It actually does sound like a cannon pinion issue, how much did you tighten it?

[david pierce]

Chaplin 37,
The mechanism that moves the minute and hour hands is actually a subsystem called the motion works. Going through this can help isolate the problem. The whole thing starts with the CENTER WHEEL which is supposed to rotate once every hour. This can be checked by marking one of the teeth and checking on it every 15 minutes or so. The CENTER WHEEL is connected to the CENTER WHEEL SHAFT which goes through the plate to the dial side of the watch. The CANNON PINION is attached to the CENTER WHEEL SHAFT with friction and the MINUTE HAND attaches to the CANNON PINION seat. The small gear on the CANNON PINION drives the large gear on a compound gear called the MINUTE WHEEL. The small gear on the MINUTE WHEEL drives a large gear on the HOUR WHEEL. The hour wheel is attached to a hollow bushing that slips over the CANNON PINION. The purpose of the MINUTE WHEEL (compound gear) is to reduce the speed of the mechanism that drives the MINUTE WHEEL by 1/12. If the CENTER WHEEL is rotating one revolution per hour and the minute hand is not, then something is slipping or is disconnected in this mechanism. The most likely culprit would be the CANNON PINION slipping on the center wheel shaft but don’t rule out looking at the other components that make up the subsystem.
david

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