Swiss threaded barrel arbor on Vacheron ~13L

[MrRoundel]

Greetings experts.

I'm just now getting around to completing (at least trying to complete) a few watches in my bench. One is high-grade pre-1900 Vacheron with wolf's tooth winding wheels. Since I have had trouble with this particular Swiss style of barrel-arbor, I have been hesitating in replacing the mainspring. But I got the MS in cleanly, as well as the inside part that engages with the inner loop of the MS. I then the winding wheel end into the inside part, but just as tightly as the mainspring resistance would allow. I figured it would be threaded in a direction that it would not loosen from MS tension. I also don't have any tool that will work well to set into the two holes in that inner spring portion in order to hold it tightly while turning the upper square with a winding key.

I got everything together nicely, and it seemed to run pretty well for a while, but then when I gave it more winds, it actually slowed down until it eventually stopped. I let down the power, removed the pallet-fork and barrel, and the train moved nicely with a puff of air from my blower. Not much in the way of recoil, but decent motion. It seems like something is binding in the barrel area. I'm now wondering if the top of the arbor, where the three screws attach through the winding wheel, is somehow binding under the barrel bridge. I oiled it, and it fit up into the recess nicely. There is a visible gap between the barrel cover and the bottom of the flange at the top part of the arbor. I suppose if it wasn't tight enough with the inner portion, that it could be sticking up to far and binding somehow.

Does anyone have any insight into this situation? Should there be a visible gap under the arbor flange, or should it be snug against the barrel cover? Any help is appreciated. I'll post an image of the assembled movement so you'd know what I'm working on.

[oldhippy]

Could you remove the wheels from the bridge so I can see under the bridge please. What does the arbor look like? is it smooth with no worn marks. 

[MrRoundel]

2 hours ago, oldhippy said:

Could you remove the wheels from the bridge so I can see under the bridge please. What does the arbor look like? is it smooth with no worn marks. 

Thanks, OldH. I'll get some images up in a little while. I take it you want all of the bridges, not just the barrel bridge?

[oldhippy]

I think the more photos you post the better.

[MrRoundel]

Well, since I already have the barrel-bridge off, I'll post that one now. More will be coming soon. Thanks again.

 

[MrRoundel]

Let me know what other angles or areas might be helpful. Thanks.

[MrRoundel]

OK, oldhippy, I think I know what you wanted to see. As I was getting ready to reassemble the movement, I took a look under the bridge to see what could be messing with the barrel. Well, there is indeed a screw that appears to be protruding too far through the bridge that may well be what's going on. It is one of the click-spring screws. It's what was in that position when I got the watch. I'll see if I have another screw that will work there. I'm fairly confident that this is where the problem lies. I'll report back after changing the screw. Cheers.

[nickelsilver]

I bet it's that screw. The upper part of the arbor doesn't move when the watch is running; perhaps as it is a suspended barrel at fuller wind the barrel tilted just a hair and contacted it. These old ones often have a number of specific screws that only go in one place. Normally every screw goes right to the other side, like bridge screws will be visible right at the level of the mainplate where the dial sits (without sticking out). These were batch made, a watchmaker might work on 6 at a time, that's why you see the 4 dots on all the parts. Interchangeability wasn't quite perfected yet. Used to be able to order spare parts from Patek for antique movements, if a wheel it was typically oversized slightly and it was expected to be trimmed down in a rounding up tool, as they were back in the day.

[MrRoundel]

58 minutes ago, nickelsilver said:

I bet it's that screw. The upper part of the arbor doesn't move when the watch is running; perhaps as it is a suspended barrel at fuller wind the barrel tilted just a hair and contacted it. These old ones often have a number of specific screws that only go in one place. Normally every screw goes right to the other side, like bridge screws will be visible right at the level of the mainplate where the dial sits (without sticking out). These were batch made, a watchmaker might work on 6 at a time, that's why you see the 4 dots on all the parts. Interchangeability wasn't quite perfected yet. Used to be able to order spare parts from Patek for antique movements, if a wheel it was typically oversized slightly and it was expected to be trimmed down in a rounding up tool, as they were back in the day.

Thanks, nickelsilver. I appreciate the additional information on the factory workings, as well as the wake-up to the fact that the barrel turns, not the arbor. Doh!

I ended up switching a click screw with the long click-spring screws. While it still stuck out a touch, it was less than it was the other way. But even after doing this, the watch stops when dial down. I'm going to go back out the long screw a bit and see if it gets freed up. I'll report back. Thanks again.

Edited February 7, 2019 by MrRoundel

[MrRoundel]

No, not the long screw stopping it. The way it's acting, I'm thinking that I might have cleaned and oiled this one before I was stopped from oiling the pallet pivots. I was used to working on larger American pocket watches, so it never gave me grief. These smaller watches definitely don't like those pivots oiled. I'll pull the pallet-fork and jewels and run them through the cleaner to see if that gets her running. Cheers.

[oldhippy]

Sorry I have been so long in replying. If no screws are fowling it up. From what you said Take a good look at the balance and everything to do with it. I don’t like the rough wear under the barrel bridge, to me it doesn’t look round.

[MrRoundel]

Good eye, oldhippy. While I don't have an image of it, when the barrel is viewed from the dial side, it is not as perfectly centered, relative to the bridge cutout as I would expect from V&C. I don't see that it touches anywhere around the edge though, FWIW.

Oh, and I will indeed investigate the balance more carefully. Last night the watch stopped in dial-up position, and the balance felt almost over-banked. I put it dial down and it started up and has run all through the night. I'll check that end-shake and roller action.. Thanks for your assistance. Cheers.

[MrRoundel]

I'm now thinking that it is an insufficient balance end-shake issue. I loosened the balance-cock screw and the balance runs longer now, and with better motion. I may end up using the cheater method of placing a shim under the inside end of the balance-cock to get it. I don't have the skills necessary to shorten the pivot(s) on the watch, and it is too nice of a movement for me to practice such things on. Since the watch is part of my own collection, I don't see it as being too evil. Cheers.