Casing a movement
Before casing a movement, always oil the winding bar in the pendant, where it runs in the sleeve, to prevent rust and squeaking. See that the movement lines up properly with the winding bar in the case, so it will wind and back ratchet freely. It is sometimes necessary to remove the winding bar and sleeve from the case pendant and enlarge the hole in it to one side or the other (with a round file) in order to get a perfectly free action. The length and position of the square on the negative type winding bar should also be inspected to see that both the winding and setting action is right. If the square is too long, it may be shortened by filing without removing it from the case. If it is too short, it is necessary to remove the crown and turn in the sleeve nut until the action is right.
The foregoing does not apply to positive set mechanism since this type of winding arbor is previously inserted in position in the movement itself.
See that the crystal does not touch the center, and that the hands clear the dial and the crystal, as well as each other. After the case is closed, hold the watch to your ear and listen if the balance pivots will “bump” clear on both endstones, as they should do, when the watch is tipped from side to side. This will indicate if the case in any way interferes with the freedom of the balance.
In casing small watches special attention should be paid to the following points: The winding crown on the end of the Winding Arbor should have a cylindrical end reaching in the case. The hole in the case for this bearing should be only slightly larger than the straight part on the Crown end in the correct position. In this way the Winding Crown will be supported in the case and dust prevented from getting into the watch.
The movement should be supported only on the case shoulder provided for this purpose, and no part of the movement should ever touch the bottom of the case. The periphery of the movement should fit in the case so the watch will not fall out if held downwards without bezel, but should be free enough so it can be lifted out without tools.
Case Screws. Modern Casing. The Hunting Case
Case Screws In the American system of casing movements, the movement was not jointed to the case but held in place by means of case screws. These case screws at first were merely short screws similar to pillar screws and screwed into the top plate so close to the outside edge
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