Omega vintage bumper repair - newbie tearing hair out...need help

[tb1982]

Hi all

New hobbyist here... after 100+hours of self flagellation I am turning to this forum for help....trying to get my first vintage beater running. Any insights 

Background:

>I have accumulated a cache of old omega bumper movements (28.10 RA, 30.10 RA, Cal 351)....mostly out of a combination of availability and the fact I like the watch, have lots of educational material on assembly and find the movement beautiful and solid to work on (less flimsy parts flying around).

>Most of these donor watches will "run for a few seconds or minutes then stop"..... main issue is with pallet fork, it will simply not snap back quickly when movement is wound up for "flick test"!! Driving me crazy...very sluggish and feel I have tried everything recommended online.

>I have tried everything to get just one movement running using various combinations of inter-changable parts but cannot get it running beyond a few minutes (at very good rate) before coming to a halt

>The movement is clean as a whistle (many rounds of us machine with naptha or IPA, reclean certain parts by hand).

>I believe the barrel/spring and wheel train is correctly installed, ml (have disassembled and re-assembled multiple times)...train runs smooth as glass and a puff of air on escape wheel (with pallet fork removed) provides an energetic turning of wheels and backlash with balance removed.

>All pivots and jewels appear to be in good shape, pegged and cleaned. Parts are old but do not appear overly worn, I have replaced any parts I view as suspect from donor movement or with new oldstock part.

>Testing fork on its own with balance in place results in steady tick/tock of fork and a clean balance swing with a puff of air, testing balance on its own also shows a functional balance

>Pallet fork seems to be locking up against escape wheel...have tried 3 different forks (all vintage parts) and cannot get it working.....

>Feel like i have exhausted all online resources and love the hobby so much but after hours and hours of observation cannot seem to get any of these running and am losing confidence.

>Any advice on other trouble shooting or tests? I feel like the advice is going to be clean the train again (which i have done ad infinitum) so I feel like it's something to do with the pallet fork but unsure why swapping it out is not helping. Alternatively I wonder if the escape wheel is messed, i cannot see any issues under my microscope, no obvious broken teeth.

>My amscope does not have a camera but can try take photos if requested via iphone and would even order a camera if it helped me share and diagnose this problem.

>It's an insanely addictive but frustrating hobby, the only upside is i have become a pro at taking apart and assembling the omega wheel train but it sucks to bump against the same issue day after day after day 

 

Kind Regards and if any of my questions are stupid so be it, have to learn somehow

 

TB

 

[Mercurial]

Given the train of wheels runs freely and reverses briefly when tested without the pallet fork, and the fact that the pallet fork action is sluggish when tested, points towards a problem with the interaction between the escape wheel and the pallet fork. 

Until the pallet fork snaps back and forth between the banking as it should, the watch cannot be expected to run well.

If the fork movement is sluggish, the balance will receive little to no impulse to keep it oscillating, and the watch will struggle to run.

A close inspection of the escape wheel, pallet fork and pallet fork pivot jewels is in order. Check vertical division, alignment and endshake - do the escape wheel teeth align with the vertical centre of the pallet stones?

Are the pallet fork stones clean and free of damage to the working surfaces? 

If they pass inspection, you need to examine the interaction of the escape wheel teeth with the pallet fork, the lock, slide, lift and drop. 

Once you have corrected the pallet fork action, such that it snaps quickly back and forth, hopefully the watch will run.

If you still have issues at this point, you need to remove the pallet fork and do a free oscillations test of the balance wheel, but for now based upon your description there is clearly a problem with the interaction between the pallet fork and the escape wheel, so concentrate on that known issue first. 

I hope that helps,

Mark

[nevenbekriev]

Something more - we here are not able to help much as we only know that the pallet fork doesn't act as it should, but we can not see why and how exactly it happens. Thus we can only give principle advice, like check everything about pallet fork, but it seems You know this already, so not of big help. Please, try to make video when You try to actuate the pallet fork. The balance out, use non-magnetic tool to move the fork. You can fix somehow you phone as to have both hands free. Locking the 'autofocus' of phone camera helps alot. Swapping parts is not correct test here, so no point to make any conclusions based on it.

[Mercurial]

I agree that photos and especially video footage of the pallets/escape wheel interaction would help us to identify the problem. 

In additional to locking autofocus, you can also use a loupe between the phone and the movement if necessary. 

Mark

[tb1982]

This is so so helpful! Thank you for taking the time to consider my problem.

i will try to examine the intervention between the fork and escape wheeel more closely but the vertical fit is tougher to view as you know 

 

I will try to make a video today which I think would be very helpful as it shows how the fork “locks” against the wheel and I’m sure you will see some thing I do not 

 

thank you again 

[Mercurial]

With the balance assembly removed from the movement, getting a side-on view of the pallets and escape wheel teeth should be easier. 

If that isn’t sufficient to get a good view, then I suggest you remove the automatic works too. 

As long as the pallets aren’t bent, getting a side view of the exit stone’s alignment with respect to the escape wheel teeth is enough to verify that the vertical alignment of both pallet stones with respect to the escape wheel teeth is ok.

If you cannot get a decent view of the pallet stone alignment with the escape wheel teeth, you can deposit a thin film of grease on the impulse faces of the pallet stones. 

Then cycle the pallet fork back and forth several times, remove the pallet fork from the movement, and you’ll see where the escape wheel teeth moved across the pallet stone by looking where the film of grease has been displaced. 

It shouldn’t be necessary to resort to this approach, but if you can’t the alignment visually, then this will work. 

Hope this helps,

Mark

[JohnR725]

14 hours ago, tb1982 said:

I have accumulated a cache of old omega bumper movements (28.10 RA, 30.10 RA, Cal 351)....mostly out of a combination of availability and the fact I like the watch, have lots of educational material on assembly and find the movement beautiful and solid to work on (less flimsy parts flying around).

>Most of these donor watches will "run for a few seconds or minutes then stop".

Normally when somebody comes the group there are base questions I like to ask like what is the watch doing before you attempted the service it? But here we find you have how many watches? Then run for a few seconds and stop was that before or after servicing?  

14 hours ago, tb1982 said:

main issue is with pallet fork, it will simply not snap back quickly when movement is wound up for "flick test"!! Driving me crazy...very sluggish and feel I have tried everything recommended online.

As you're new to watch repair there is no main issue because you're having probably lots of issues. But we can go with the pallet fork issue for now we need a side view of the pallet fork out of the watch so we can see the pivots. Then we need lots of pictures the pallet fork in the watch from a variety of directions. Remember your the eyes on the watch and were attempting to diagnose based on your descriptions and as a newbie you're going to miss things lots of things which is why we need the pictures. It's quite amazing what a small group of people will see when looking at a picture. Yes we've all had different experiences which means when all of us look at the pictures conceivably will see something slightly different which is why group help is quite helpful for problems.

 

14 hours ago, tb1982 said:

I feel like the advice is going to be clean the train again

Strangely enough this suggestion comes up quite a bit on this discussion group. Typically it's the newbie in other words my watch is not running I will clean it again. But unless cleaning is the problem cleaning again isn't going to fix the problem.  But it does seem to be the favorite repair tactic of newbies cleaning the watch again which in reality you need the practice of disassembling and reassembling anyway.

14 hours ago, tb1982 said:

so I feel like it's something to do with the pallet fork but unsure why swapping it out is not helping.

Maybe that's because it's not the problem?

14 hours ago, tb1982 said:

It's an insanely addictive but frustrating hobby, the only upside is i have become a pro at taking apart and assembling the omega wheel train but it sucks to bump against the same issue day after day after day 

This is where you need to stop doing what you're doing take a step back and evaluate the situation where is the problem? It might even help to just take a day off and approach the problem with a new set of fresh eyes rather than repeating the same steps over and over and over again which you seem to be doing quite consistently with the exact same outcome.

Then you can help us out with pick one watch it be really nice it was a watch you never touched before so we can start fresh but I'm guessing that's out. I don't suppose you know the condition of the watch before you attempted to service it?

We need the exact model number of the movement. Generic questions of I have a dozen Omega watches all doing the same thing is not helpful as each watch tends to be unique with unique problems.

Then if you could remember what exactly you've swapped on this watch in other words which parts did not originally come with the specific watch that would be helpful.

Then as were reviewing everything you're doing what lubrication's are you using on the watch?

7 minutes ago, Mercurial said:

If that isn’t sufficient to get a good view, then I suggest you remove the automatic works too.

This is where newbies shouldn't be starting on automatic watches as it adds to the complications of. Plus these are not your normal automatic watches anyway their vintage automatics which are going the present some interesting challenges all by themselves. Plus the automatic shouldn't even be added in until the watches running anyway.

 

 

A

 

[tb1982]

Hi there,

I have taken a few videos, just trying to reduce in size and figure out how to upload with an extension the site will accept.

To answer your other questions

1: I did NOT start on vintage watches but have disassembled and re-assembled multiple ST36, Unitas and Seiko movements and re-assembled to better than before condition. I am not sure the criticism is helpful or necessary in this case. 

2: I have replaced the 4th wheel (with a new omega part), I have replaced the main spring (new omega part), I have tried 3 used pallet forks.

3: Exact movement is 28.10 RA which uses the EXACT same pallet fork as 30.10, 351

4: Lubricants - 9010, 9104, 9145 (for exit stone)

5: Thank you to all the helpful/proactive and encouraging advice.

[tomh207]

@tb1982 the site doesn’t allow for the upload of video files. The accepted way is to host them somewhere like YouTube and then link to them here.

 

Tom

[tb1982]

Thank you Tom! makes sense and sorry for missing that 

[tb1982]

Video Link 1:

 

[tb1982]

 

[tb1982]

Condition of watch at arrival: Running for a few seconds then quits. i.e. this is an attempted repair/restoration. Obvious observed fault was a broken mainspring of original watch and very dirty pallet fork.

 

 

[RichardHarris123]

The pallet fork isn't snapping back and forth as required, next need to find out why.

Edited January 9 by RichardHarris123

[tb1982]

I will assess the side view interaction very carefully and report back with photos 

[nevenbekriev]

If I understand correctly what happens, You must help the pallet fork to move to the other side sometimes, it not always wants to do it by itself? If so, then there might be no axial free play of the staff. Can You check it? Check the axial free play of the escape wheel - grasp the pinion with tweezers and move it up/down and will see that it moves a little. About the same movement must be in the pallet fork staff. Does it?

[tb1982]

Hi Nevenbekriev, that is accurate, i must often actually nudge the fork side to side. I will examine as you ask and report back tonight.

[tb1982]

There is essentially very little to no movement on either fork or escape wheel (in the vertical direction), is that a problem? 

[RichardHarris123]

Reread your post, you said the wheel train is moving freely without the pallet fork being in place, can you confirm?  If so, the problem us with the pallet. 

[JohnR725]

3 hours ago, tb1982 said:

2: I have replaced the 4th wheel (with a new omega part), I have replaced the main spring (new omega part), I have tried 3 used pallet forks.

3 hours ago, tb1982 said:

Exact movement is 28.10 RA which uses the EXACT same pallet fork as 30.10, 351

Yes I did looked up all  the movements use the exact same pallet fork except?

If we were dealing with a modern watch the parts are mass-produced they will all be exactly the same. You never have to adjust or do anything to just drop right in but is this a modern watch?

If you're dealing with vintage like I typically deal with mixing and matching parts is a very bad thing. Especially escapement components as they were adjusted at the factory for each watch they were in. It's why they had things like movable banking pins the banking pins could be moved because the manufacturing was not precise enough.

Then your watches are vintage? What I do not know is whether at the time these were made were the pallet forks adjusted for the specific watch? Plus and the plus factor is a huge factor with these watches Has this watch ever been worked on before?

Oh and it probably does not apply here but the exact part numbers and exact part numbers off the technical bulletins are not always exact? A lot of times the watch companies had supplemental information Omega has a lot of supplemental. Updates to technical bulletins updates the supplemental information with the supplemental information normally not available out in the wild. This is extremely common with modern Swatch group. So in other words if you had a older technical bulletin here repairing it exactly as specified replacing the parts exactly as it says well you're doing it wrong because you're missing at the supplemental information.

Now back to your pallet fork as you're not really a  newbie you have experience you know what the pivots look like. You want to look very carefully at the pallet forks and see if that looks like the shellac has ever been changed and/or modified. Then it's possible you may just need to adjust the stones for the particular watch that it's in. Plus also check if it has banking pins are usually not movable but creative souls like the bend them for a variety of reasons like if they change the pallet fork for instance. Which by the way is actually something taught in Swiss watch schools bending banking pins to accommodate the pallet fork.

 

3 hours ago, nevenbekriev said:

Can You check it? Check the axial free play of the escape wheel - grasp the pinion with tweezers and move it up/down and will see that it moves a little. About the same movement must be in the pallet fork staff. Does it?

Because the unfortunate reality of other people possibly playing with the watch things get adjusted and yes this is an outstanding suggestion. The pallet fork has to be extremely free if the watches going to work at all. So definitely check the end shake of that and anything else for that matter. Rolex is really obsessed with checking and shakes of all other wheels.

[Neverenoughwatches]

1 hour ago, tb1982 said:

There is essentially very little to no movement on either fork or escape wheel (in the vertical direction), is that a problem? 

If they don't both move freely then yes. Essentially trapped between the bottom plate and their respective bridges. To fully identify this as a no endshake issue, fit those two components into their bearings in isolation and then check for free motion. 

[JohnR725]

1 hour ago, tb1982 said:

There is essentially very little to no movement on either fork or escape wheel (in the vertical direction), is that a problem? 

I really should read the entire discussion before answering questions yes that's definitely a problem.  Oh and when you're checking for play make sure there's no power on the watch as that will prevent you from checking for play but yes there has to be a small amount of play in the wheels.

I don't suppose you have a tool for adjusting jewels?

[Jon]

Ideally, from the side your escapement should look like this. As others have said, the end-shake of the pallet fork and escape wheel have to be the same, otherwise the escape wheel tooth will hit a different part of the impulse face of the pallet jewel in dial up and down positions. The escape wheel tooth should be hitting half to 3/4 the way up the pallet impulse face, as the diagram shows. If you have a jewelling tool this would take no time at all to adjust both the escape wheel and pallet fork end-shake to be the same. You might have to move the pallet fork up or down on the arbor to suit. Remember the guard pin should be in direct line with the safety roller in both dial up and down and the fork doesn't scuff the underside of the roller in dial up position.

This WOSTEP handout will help

WOSTEP handout.pdf

[tb1982]

Thanks Jon, I believe this is the issue, misaligned fork and escape wheel (in the vertical axis) and non-identical end shake.....might have hit my limit on this one as I'm not ready to take on these adjustments and start adjusting jewel depths. 

I really wanted to thank everyone for their amazing help 

going to test for movement in their own bearings (with no train) and try a few other plate/bridge combos to seen any have better movement 

[fellerts]

On 1/8/2025 at 9:45 PM, tb1982 said:

Most of these donor watches will "run for a few seconds or minutes then stop"..... main issue is with pallet fork, it will simply not snap back quickly when movement is wound up

It sounds like all your donors suffer from the same problem... How is it possible for so many movements to have reduced endshake in the escapement? Someone correct me if I'm wrong, but endshake typically doesn't change unless someone goes in there with excessive force or a jeweling tool, or perhaps changes out components with no regard for them being matched at the factory as John suggested.

I'm not sure what I'm getting at, I just find your situation very curious. Are we missing something here?