Eta 2550 Ladies Movement Pallet Fork End Shake.

[ligangyi]

Got one of these serviced over the last weekend. The movement is really tiny and challenging to put back together. It was cases in one of those one piece 10k gold filled Hamilton watches.

Upon reinstallation of the pallet fork. I noticed it to have a little more play then what I'm used to. The movement still runs but I'm not sure what I can do to correct this. Would you guys try moving the upper and/or lower jewels closer together or get a new fork before doing that?

[Geo]

Check out this link Ligangi, you should find all the information you require here.

http://raulhorology.com/2012/10/setting-up-the-escapement-eta-6498-end-shakes-divisions/

[clockboy]

Great link Geo, Ligangy I would look at the jewels with a strong loupe first just to double check you have not got a damaged jewel that is causing the play. If OK with the strong loupe then check the pivots of the escape wheel to check for damage. Only if the last two are absolutely Ok would I move the jewels.

Edited March 2, 2015 by clockboy

[ligangyi]

I need to take another closer look at the jewels in that area. Assuming it's the jewel in the bridge that's bad (either moved or damaged), how close tolerance do you guys think a replacement bridge will be? I'm asking because right now I don't own a jewelling/staking tool, just exploring my options.

[clockboy]

If it is the pivot on the escape wheel it,s a simple job of replacing it if you can purchase a new one. If it is a damaged jewel I would not attempt this job without the correct tool. Apart from the fitting (friction fit) replacing the damaged jewel to the correct height is also important.

[ligangyi]

Hi there clock boy. Yeah I can understand that how far in the jewel sits will affect end shake. I'm just torn right now between really needing to get a jeweling tool to get it right or try and get around that with carefully staking and testing it out. The third option of course would be to accept that this will become a donor movement, but I'd really hate to see that. Thanks for all the help so far.

[ligangyi]

I just took another good look yesterday evening. Both upper and lower jewels look good. The pallet fork pivots looks okay. There is still too much end shake on the pallet fork. I can maybe move the pallet fork about 1mm. I have used an app on my Android that works like a time grapher and the line is not flat and it's not because it is out of beat. Somewhat like a bit of snow going across.

Fairly sure it's due to the shaky pallet fork. I'm waiting on a parts watch to determine if its the pallet fork or the jewels are the issue.

Edited March 9, 2015 by ligangyi

[Geo]

Hi Ligangyi, if you have 1mm end shake on the pallet fork that is ten times the requirement. You should be looking far about 1/100th mm end shake, with the periphery of escape wheel in line with the centre of the pallet jewels. To achieve this accuracy you will require a jewel press.

[anilv]

1 mm is a lot... are you sure you're not missing a cap jewel on the dial side?

 

Anil

[ligangyi]

I don't think there's a cap jewel on either side. Just hole jewels. Also the pivots of the pallet fork aren't protruding all that much out of the hole jewel for a cap to work. The pallet bridge is held on with a single screw and is like an arm extending over the upper pivot, I've tried looking at it straight on but it doesn't look noticeably bent. I'm waiting on a parts movement to make sure I have at least the correct pallet fork in case that is the issue here.

[clockboy]

Can you send a Pic. You can use your mobile telephone & just put a loupe over the lens to get magnification. Perhaps we can then see the issue

[ligangyi]

Here's a picture without the balance. The end of the pallet fork can be moved up and down a whole lot. I took the pallet fork off a couple of times today to try and see where the issue again is. After prodding around with a sharpened piece of pegwood to see if anything was loose, I prodded the lower jewel gently and it flipped over in it's hole! So I guess I have found my problem, although I don't think I can fix it as of now.

 

I'm guessing the hole in the plate has somehow loosened up over time and thus I'd need a new jewel with a slightly bigger OD and have to oversize the hole in the plate? I'll probably keep this movement around until I gather enough tools/skills to get it repaired properly. Thanks for all the help guys, I was so stuck for these couple of days.

 

Although I couldn't fix it this time round, it's a relief that I found out why the pallet was loose.

 

 

[Geo]

That's a great bit of detective work Ligangyi. At least you found the offending part, and hopefully you will be able to fix it yourself once yo have the experience and the tools. :)

[AlexanderB]

I bought a couple of ladies watch movements on ebay and one is a 2550 (among four 2551) which I just diassembed. Was looking for information about the movement when I stumbled over your thread.

I was curious and merely assembled the pallet fork and its bridge to see how mine is doing. I can move the end of the pallet fork maybe not 1mm but certainly half a millimeter up and down where it meets the balance wheel.There is a significant axial play. I have to say that I'm new to watch repair so I can't really judge it. Looks OK to me.

My movement was in a pretty bad condition, the balance spring was broken (never saw that before) but the stones of the pallet fork look OK and so to do the pivots. I will do some cleaning excercise on this movement. Won't run with a broken hairspring.

Is it possible that this is by design?

Cheers Alexander

[bobm12]

Hi Alexander,

The tiny movements I've found to be a challenge! I don't work on them much so my opinion is not 100%...I think others can say if I'm right or wrong. But my two cents is that those tiny movements do wear faster than the "regular" size ones. It is possible the wear (since both of you in this topic are dealing with old movements), have altered the "fitting". So, in a nutshell, I believe the extra play you are seeing is simply wear. It is possible you guys need to replace the pallet fork if available or make -- if at all possible - a new staff for it...I believe Lawson made an excellent walkthrough of this you guys may want to check out.

Cheers,

Bob

[AlexanderB]

Hi Bob,

you are absolutely right. Quite fiddely stuff. But since I got so many smaller movements (just bought a lot cheap on ebay) I tried dealing with those. Can you imagine that I bought 18 small movements (among them 5 x 2551) some including dial and hands, for 39 EUR including shipping. Some of them are broken, like the 2550 I was just disassembled. They are perfect for me to train my skills. I Can learn how to clean the parts and will do some testing with my ultrasonic cleaner (how long can I clean before damage starts). Cleaning the pivots, jewels and the geartrain can be done esasily.

Regarding the pallet fork it is impossible for me to judge. I have some PUW 1175/1177 which are unused (also 20 pieces cheap on ebay, but only five still had the balance wheel). I will check the play of the pallet for on one of those. Pretty much the same size.

Will come back on this.

Cheers Alexander

[AlexanderB]

Short update: I just looked at my PUW 1175 and there is some axial play in the pallet fork but indeed not as bad as in the old 2550. I would say this porves Bob to be right and that there is a significant wear.

Looking forwart to other opinions and of course to what ligangyi comes up with.

Cheers Alexander

 

[oldhippy]

Regarding the size of the movement has nothing to do with the wear and how long the movement lasts. Movements will only wear out fast if they aren't maintained properly. A simple example poor lubrication.

Are you sure the pallet bridge is sitting correctly and you are using the correct and original screw. What about the pallet bridge is it right and not out of line. Are the jewels level with both plates and tight and are the pallets right, not bent or out of line. Check that the roller is correct and hasn't been fiddled about with because that can cause the watch to knock and cause snow on the timer. Do not oil the pallet pivots they don't need oil.