There are a number of reasons why a novice might want to remove a pocket watch from its case. The article below is intended to provide basic instruction on how to do so for American pendant-wind pocket watches. .A large number of Swiss movements and a small number of American movements (most notably Elgin's grade 571) have what is referred to as a "Swiss style stem" and it is recommended that the removal of these watches from their cases be left to more experienced people. You'll know its a Swiss style stem if you follow the procedure below and the movement does not come free of the stem.
Why Remove A Movement From A Case?A movement needs to be removed from its case for service - repairs, or just a cleaning and oiling. However, this article is intended for novices and their reasons are likely to be more basic. One possible reason might be to be able to remove and clean the dial. Another reason might be to exchange the case. An example of this might be removing a hunting-case movement from an obviously non-original, open-face case in order to place the movement into a display case.
Is There Anything Wrong With Changing A Movement To Another Case?A number of watch collectors feel that a movement should not, under any circumstance, be separated from its original case, and there is a lot of merit in this admirable attitude. Other collectors rightly feel that if the movement wasn't factory-cased, there is nothing sacred about the movement/case combination (barring some special significance of the original owner) and that there is nothing wrong with changing cases. One would hope that in doing so, the movement and new case combination are age appropriate, but there are no strict rules. Each collector has to decide what to do, or not do, for himself/herself.
The Movement Comes Out The FrontThe movements of almost all of the American-built, pendant-wind watches are removed from their cases by coming out the "front." If the case is a swing-ring case, comments about the center ring or rim of the case pertain to the swing ring in which the movement is mounted. Since the movement is coming out of the front of the case, open both the case back and bezel (if necessary, refer to the Encyclopedia article entitled "How To Open A Pocket Watch Case").
On hunting-case watches, the bezel snaps off. Look carefully at it. Notice that there is a long slot by the hunting cover hinge and a shorter slot 180 degrees around at the latch. There might also be a very small slot into which a locating pin from the center ring of the case fits. This assists you in getting the bezel in the proper rotational position when putting it back on. If the watch is lever-set, there'll be a small slot at the lever (pull the lever out when replacing the bezel - this ensures that it will fit over the lever properly). Finally, you'll find a small slot into which a fingernail will fit. Once you place your fingernail in the slot, slide it in either direction and the bezel should pop off. Resist the urge to pry with your fingernail, that might just lead to a broken nail.
Unless the case is railroad model case, the crown pulls out to what is normally the winding position. Pull it out at this time. This action also pulls the stem to a position that is a little bit less engaged in the movement.
The Case ScrewsThe vast majority of American pendant-wind pocket watches are held in their cases by two case screws. Although they're called "case screws," they screw into the movement. The case screws may be identified as being the ones with large diameter heads which extend beyond the movement, over the rim of the case. Turning the screws counter-clockwise allows them to be removed. On a few watches, notably the Swiss Record-Ball caliber 435 series, the screws are to be turned clockwise. These movements have small arrows indicating clockwise rotation.
Some case screws have a partial head, about 30% of which is missing. This is to allow the movement to be removed from the case without totally unscrewing the screws. For this type of screw, just turn it counter-clockwise until the screw head clears the case rim. When returning the movement to the case, you might want to back these screws out another turn or two in order to make it easier to screw them back onto the case rim.
Removing The MovementIn the following step, hold the watch in such a way as to be able to support, or catch, the movement as it leaves the case center ring. Once the case screws clear the case, press lightly on the edge of the movement, 180 degrees away from the pendant, pushing it out the front. The movement should pivot outwards, clearing the rim of the case and also clearing the square stem from its hole. Its sometimes helpful to slowly rotate the crown counter-clockwise as you're easing the movement clear of the case.
If the edge of the movement clears, or almost clears, the case (180 degrees away from the stem), but doesn't easily come free of the stem, it might be a Swiss style stem. If this happens, put everything back together and seek out a more experienced person.
Returning The Movement To The CaseWhen returning the movement to the case, be very careful not to press on the dial to push the edge of the movement back into the case rim. It should "drop right in," especially if the crown is being rotated slowly in a counter-clockwise direction. If the watch is lever-set, pull out the lever before fitting the movement into the case to ensure that the movement is positioned properly to allow the lever to operate smoothly in its slot. Insert and then tighten the case screws and close up the watch.
Possible ProblemsIt's possible that the movement may not fit in the "new" case. The likely cause is that movement sizes are only nominal. Watches that are supposed to be a given size, may actually be a little bit larger. One example is the 16-size Waltham model 1872 which is larger than a 16-size case. Another example are the Hampden models 1 & 2 16-size movements which are a little too thick to fit in the "standard" 16-size case.
Another problem may be that the lever does not line up with the lever slot in the "new" case. This 16-size example has its lever a little bit beyond the "normal" six-minute position. In such instances, the choice is to find a more suitable case, or re-cut the lever slot to fit. Of course, this presupposes that the case has a lever slot to begin with, and that the movement is lever-set
No doubt there are other problems that will crop up, but learning about them is what helps one graduate from being a novice.