Now that I've finished a couple of other projects, I can start on this nice little Elgin 12S pocket watch dating from 1921. Checking the serial number we can get something almost as interesting as an Omega "Extract of the Archives". Production Year : 1921 Size : 12s Jewels : 15 jewels Grade : 314 Model : 2 Class : 113 Run Quantity : 2000 Production Dates : 1903 to 1927 Total Grade Production : 323000 Movement Configuration : Hunter Case Movement Setting : Pendant Wind and Set Movement Finish : Nickel Damaskeening Plate : 3/4 Plate Barrel : Going Barrel Adjusted : No The case is in good nick for its age so the promise of 20 years Warranty by the case maker (Bates and Bacon of Attleboro, Massachusetts) has well and truly been met. Like many watches from this era, the enamel dial shows no signs of age as later painted/varnished dials do. The movement is fairly standard for an American watch of this era. The regulator is to me, particularly attractive and allows very fine micrometer like adjustment. So there we have it. Next steps are to start disassembly (no timing checks, it just doesn't run).
Disassembly is straightforward, being pendant set there is no reason to remove the stem. It's just a matter of removing the front bezel/glass, undoing the two case mounting screws at the rear and sliding the movement down and out, or in this case, across and out away from the pendant. The first thing I remove is the balance assembly so that it can be safely stored while I remove other parts and inspect components. I thing I've found one reason why it didn't run . After the hands have been removed the next thing is the dial. This is a recessed style where the dial is fitted closely into the main plate. After removing the three dial screws I found another feature provided by Elgin to save hasty watchmakers from trying to prise the dial out of the plate with a pocket knife. Just next to the dial screw hole is a small holes that allows a suitable tool to be inserted to push the dial from below, lessening the risk of damage to the face of the dial. So using a suitable tool, I found it quite easy to start lifting the dial. and all done. Next will be pulling the movement apart and eyeballing the bits and pieces.
As all men know, it's nice to have a "bit'o'fluff" now and again. But not when it's INSIDE a watch! There's enough in the movement to stuff a decent size pillow! I'd already removed some other lint balls, one was under the balance wheel so that could have been the problem.
All of the major parts have been broken down. Tomorrow some inspecting before going into the cleaning machine. Any hints on the first thing needing replacement? And what main components haven't been disassembled?
Correct. But as @Canuck noted, crown wheel screws are usually LHT, and identified by lines or rings on the screw head. This watch has a hub or core to secure the crown wheel so may not require a LHT screw and is not marked like one. I tried both directions with reasonable force but no budging so I'll try a penetrant soaking to see if I can free it up. I just need to know if it's a normal thread, or a lefty. Anyone? There is also a "mystery" screw in the bridge. I can't figure out what it's for and looking at the underside it doesn't seem to connect with anything. Anyone have an answer on this one?
A Links https://mb.nawcc.org/threads/ratchet-wheel-screw-always-reversed-from-direction-of-turn.119163/
Thanks Geoff. I thought that would be the case but not being marked was enough for me to be cautious. Add to that comments like: "Crown wheel screws are left handed, except when they aren't. Left hand threaded screws have 3 slots in them, except when they don't. That pretty much sums it up. Cheers, Al" and "Fletcher's book "Watch repair as a hobby" has this: "Now remove the ratchet wheel by unscrewing the screw at its centre; this is either right-or left-handed according to the whim of the maker."" Anyway, the good news. After a few hours with a drop of penetrant on the underside, and another attempt for a LHT screw it came loose quite easily.
I figured out the mystery screw. As the setting parts are pendant set, the winding parts are spring loaded to the hand setting position so that when the pendant (crown) is pulled out the parts are pushed into hand setting mode. When the pendant is pushed in, the parts are pushed against the spring pressure into winding mode. However, when the watch is removed from the case, there is no pressure from the pendant so it jumps into hand setting mode. In order to have the movement in winding mode out of the watch, the mystery screw is turned in until it meets resistance while the movement is in the case. The point of the screw engages a detent in the "winding bits blocking gizmo" (see arrow below) that stops the rotation of the bits and holds it all in winding mode.
Hi Jim, Yes, I wrote that a few years ago and yes as the other fellow wrote, it's at the whim of the maker. I've seen LHT screws that are marked with three slots, some with the regular slot with a second shorter slot perpendicular to the regular slot, and lots that are simply not marked at all lie this one. If you have ever taken apart an ETA 6497/6498, then you have seen a LHT crown wheel screw that isn't marked as such - it's just a regular single slot. As for the "mystery" screw, well watch movement designers/engineers don't usually include screws for no reason. BTW make sure you have a good look at all the jewels. I have had so many US made pocket watches in with cracked and broken jewels, it seems like every one of them has been dropped at some point in it's life. The bezel set (rubbed in) jewels are getting hard to find these days, so unless you already have a stash of them and can colour match them to people's satisfaction, then these can be a real pain. One reason why I stopped working on them a few years ago... Cheers, Al
Matching jewels in 100 year old watches certainly can be a problem. Some years ago, I sorted through my stash of un assorted jewels, to pull out an assortment of genuine ruby jewels, and arrayed them in colour gradation, to show the huge differences in colour. Some of the pink colour seen in the paler rubies is euphemistically called “pink sapphire” in jewellery stores today. “Pink sapphire” must bring a better price than poor colour ruby. There is a blue sapphire in there as well. Ruby and sapphire belong in the corundum family of gemstones. Rock crystal and aquamarine (and garnet) were also used for jewelled bearings before the development of synthetic, man-made ruby. And needless to say, also diamond. I don’t know if the same terminology is used in colour grading ruby today. But Burmese ruby (now Mayanmar) in the finer grades, is best. Then Siamese (now Thailand) is next, then Ceylon ruby. Siamese and Ceylon ruby are the paler colours that you see.
