Adjusting the Crown on a Grade 73 Elgin

Here we have an 18 size Elgin watch, 7 jewels, made about 1892 featuring a swing-out case with an older style stem-set mechanism.  The sleeve on the stem is built in to a top cap that threads onto the top of the neck of the case.

In general, the sleeve is a sort of spring that grips the stem.  The stem is the shaft that connects to the crown and goes down into the watch movement itself.  The stem will have a ridge and a shoulder in it at some point so that the sleeve snaps, over the ridge, from in position to out position.

Back to this watch, it is much more common to see cases were the sleeve threads into the neck of the case, as a separate part and there is no cap piece.

But stems and sleeves are a topic for another day.  This watch has an interesting problem related to the crown.  At some point it appears that the crown has been replaced with one that is not going to work.

The crown threads down on the stem.  Pulling and pushing the crown thus moves the stem in and out.  The bottom of the crown will, or should, come near to hitting the top of the cap on this case.  That would be the most the crown can be pushed down.  And that needs to be far enough for the stem to snap, and press into the movement far enough to engage the winding mode.  But this crown hits the cap too soon and can not be pushed down far enough to snap into winding position.  This was the owner's complaint - the watch seems "stuck" in setting mode.

To solve this problem the crown needs its inside cut back so that is will go down further before coming to the top of the cap and being stopped.  To do this we use the lathe and a special crown chuck. This chuck is basically a cup with an assortment of different sized threaded caps that hold the crown down in place against a pad inside the cup.  The caps are open-ended, exposing the crown.

Here we see the crown placed into the crown chuck.  The bottom of the crown is exposed.

And here we see the chuck set up, centered and true, in the lathe.  This now allows the inside of the crown to be cut back without damaging the crown.  The job is done slowly, taking several measurements.  It is important not to remove too much and leave the crown feeling loose when pressed down on the case.

Here see see the cut done. Compare this to the photo above.  The shine of the freshly cut area can be seen inside the crown.  The crown will now travel down over the top of neck of the case far enough that the stem will snap the key-less works of the movement into winding mode.

The watch is now ready to go, setting and winding working fine, ready to tick off countless days to come.