The mainspring broke after a couple days of running. I'll change it out, then start the test cycle over.
Elgin serial number 3793826 is a grade 70, 18 size, 15 jewels, made about 1890. This is a B.W. Raymond model.
Showing posts with label Mainspring. Show all posts
Showing posts with label Mainspring. Show all posts
Job Number 250148
The mainspring broke after a couple days of running. I'll change it out, then start the test cycle over.
Job Number 220082
The movement is a grade 208, 18 size, 7 jewels, made about 1900.
Follow the album for this project here:
Job Number 220002, Continued
Miraculously, a source turned up with a cache of NOS parts for this complication. They weren't cheap, but they're here and it looks like it will all work.
The parts will work, but there is one problem. The stack of gears that
transfers motion from below the mainspring to the dial side is too tall.
The barrel bridge does not sit all the way down in place. The part that
solely (as far as I can tell) dictates that height is the pinion 'G'. All
the other parts have a fixed size and the arbor of the assembly just
floats at the lower end so it doesn't care.
On close examination, I noticed that part G is really rough on one end in
particular. On the other end it flatter, but does have a barely notable
lip on the hole. These ends should be polished smooth.
Here is the slight gap, visible at the left end of the upper plate as it sits on the up/down assembly. It seems like the pinion needs to be shorter by that amount.
I need to study the whole thing more and think about it before doing
anything though.
When I first started watchmaking around 2000, I had 3 or 4 of these barrels. They all have been used in repairs. I did not at the time realize how scarce they would become.
By the way, most of my project get a single blog post. Some, like this, will have more than one. To look for project posts, use the search box with the job number. See all the posts for this project here.
Job Number 220006
Well that's a broken mainspring ... Also a broken tooth on the ratchet wheel.
Over on Instagram I received several comments and a couple direct messages about this image asking how this could have happened to a mainspring.
Although this is a spectacular case, it's not uncommon with old steel springs. The watch was wound up when it stopped running for what ever reason. The spring was at least mostly coiled in toward the middle. It partly "set" in that shape over time, so tension on the coils was uneven. There was some rust that weakened the material. The outer coils just gave way at some point and opened up, while parts of the spring stayed "wound" in the middle. The weakness and uneven tension cause multiple breaks because the spring can't uncoil.
Everything is in really nice condition. There's a slight grain to the finish on the plates.
I ended up replacing the upper balance jewel due to just a bit too much wear. A hairspring adjustment was also called for, and I am pretty sure that still isn't quite right. It's always a pain with these smaller Elgins... I'm leaving it in the case running for awhile, so the stem will be in winding mode.
It took quite a lot of work to get the rate in the ballpark, but it's finally ready for a few days of testing. Mechanically, just as far as running correctly, it's very good.
Job Number 210157, Elgin Grade 240, B. W. Raymond
It's a motor barrel so the barrel came right apart as I disassembled.
The movement is an Elgin grade 240, 18 size, 19 jewels, B. W. Raymond model, made about 1909.
Assembly seemed to go well... at first.
At first I thought either of the parts might be an incorrect substitute. Some Elgin bevel pinions have an extra shoulder at the back that would perhaps cause it to sit further up. But I was able to determine that all these parts were correct by comparing them to a Veritas I happen to also have on the bench. The bevel pinion can move up, as shown here. But the clutch is as far back as it can go in winding mode in this image. What could the trouble be? Quite a mystery...
In the old Google+ days it was easy to turn this sort of thing into a watchmaking puzzle and post the answer later. Here, I guess I'll just go right ahead and divulge the problem.
On the dialside where the lever is, there is a spring loaded cam that pushes the clutch into winding mode "by default". When the lever is pulled out, it pushes the setting lever, and thus the clutch forward into setting mode.
The setting lever cam was installed incorrectly such that the spring pushed the clutch into setting position, and block it from going all the way back for winding. The direction the clutch push by default was the clue. The last person in this watch took the setting lever off and and put it back on the wrong side of its spring.
This shows riveting on the new staff.
The roller table for this movement is a double roller in two parts. I guess I didn't take a picture of that. It takes some extra careful work to assemble. You can see one of these here.
Running well so far...
I replaced one of the plate screws that was an incorrect style, and added a couple of timing washers. It's now ready for a few days of testing.
Job Number 210153, Hampden Special - Before
Unfortunately this spring is a bit scarce. I don't think I have one. The hunt is on.
Clearly this one has not been cleaned in a long while.
The album for this project is here:
https://photos.app.goo.gl/2NgeUAoC7LyX8FV98
https://photos.app.goo.gl/2NgeUAoC7LyX8FV98
Find more Hampden examples here:
Job Number 210151, Elgin Grade 478
It had a broken mainspring but no other problems. Can you spot the break?
Both case and the movement are marked B. W. Raymond. The case mark is rather rare.
See the album for this project here:
https://photos.app.goo.gl/VWfGeppiZposjhvB7
https://photos.app.goo.gl/VWfGeppiZposjhvB7
Job Number 190043
The crystals are not supposed to be this way, they were originally clear. Over decades these early types of plastic decayed and changed. While doing so, they gave off a corrosive gas that very commonly, as is the case on this Hamilton, severely damages the hands and often the dial too. In the worst case, the corrosion will extend to internal parts inside the movement through the center of the dial.
It's temping to think that plastic crystals are always "cheap" replacements. But this is not necessarily so. Plastic crystals were considered a technological improvement over glass as they were said to be "unbreakable".
Some people prefer to leave these crystals on as original. This may be fine. Many believe that the degassing stopped long ago. On the other hand, some say that the old plastic crystals should always be replaced to avoid the risk of further damage. I don't know. This plastic crystal was replaced with glass.
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