Job Number 180017

This watch was sent back to me for being very hard to set. The movement is stem setting, it goes into setting mode by snapping out the crown.

Vintage American watches, usually, are what we call "negative setting" (modern watches use a "positive setting" design). On such a watch the pieces inside the neck of the case do the "snapping in and out", The watch movement actually has nothing to do with it.

These photos show the stem and the sleeve. The sleeve, with the stem inside, screws down into the
neck of the case. The crown then screws onto the thread part of the stem.

You can see a bump or ridge in the stem where the stem is bigger around. Below that is a much larger round section, and below that the shaft is square. Proportions vary from case to case, but almost all
vintage American watches have this.

The square part is what goes into the watch. It turns the winding arbor, which has a square hole in it. Nothing in the watch grips this square part, the size of the square part just has to match the hole in the arbor.

The next up, larger round section is what stops the stem from pulling out of the case. As it is pulled out through the sleeve, that fat part bumps into the tips of those spring like fingers of the sleeve and stops.

That next up bulge is what snaps to one side or the other over the fingers to make the stem snap in and out. To snap out, the stem has to be pulled so that part snaps over and past the sleeve tips.

The narrowness of the springy fingers of the sleeve and the size and abruptness of the ridge in the stem dictate how much "snap" the case has.

It important that this be just right. If the stem moves over the sleeve fingers too easily it will pop out into setting mode on it's own. Sleeve fingers are prone to breaking off leading to this situation.

There is no way to adjust the stiffness of the snap, as you can see. There is no screw to loosen or anything. Lubrication won't make any difference either as it will not
change the fingers of the sleeve spring.

My only choice is to trim a tiny, and I do mean tiny, amount off that ridge in the lathe.

This has to be done with care. You can't put metal back if too much is removed.

It's worth noting here that there is no standardization to the sizes of any of these parts. The stem's length, the diameter, length and position of all those sections of the stem, the thread pitch on the crown end, length of the sleeve fingers and the size and pitch of the threaded part of the sleeve, all of it, are all uniquely fit to each specific combination of the movement and the given pocketwatch case.

The one and only adjustment possible is that the sleeve can be set to differing depths in the neck of the case.

By making this slight change I can make the crown just a little easier to snap out and set the watch.