Help Chasing Amplitude Issues

[mzinski]

Before I dive into it, thanks you all for being here and answering my wide array of watch repair questions. It's hugely appreciated for a hobbyist like myself. 

So I'm trying to restore a nearly vintage Rolex 16610 - instead of just being old it was old and trashed! Thankfully the thrashing was mostly saved for the case. I have, so far, disassembled, cleaned (twice now in search of my issues), inspected, lubricated, and inspected some more. Replacement parts have been main spring (Startime Swiss premium), stem, case clamp screw, sliding winding pinion, lower escape wheel cap jewel and shock spring (not damaged, just lost), upper balance wheel cap jewel (jewel had a slight divot in the center). 

I'm finding the movement is exhibiting lower amplitude than what I usually achieve with a mid-90's Rolex 3135. I'm only hovering near or around 270. 

In addition to what I find to be low amplitude, I'm finding a frustrating differential between dial up and dial down positions - about 5 sec beat rate delta and 15-20 point amplitude delta. 

I'll also note, the amplitude fluctuates a bit dial up, about 10 points. I estimate it occurs every 60 seconds but I haven't gotten on to timing it yet. 

I have looked at the end shake on the balance, pallet, and escape wheel. All have some end shake and nothing appears excessive. The train provides nice recoil with three clicks of the ratchet wheel. 

I'll note the barrel arbor fit into the mainplate a bit tighter than I would expect/like. I have not gotten around to trying a different arbor but I will also inspect/test this. 

To be honest, I don't know how to measure it precisely though. I have experimented with increasing and decreasing the end shake (it's so easy on a 3135). This has not solved the issue. 

I've inspected the pivots with the highest magnification I have, 10x loupe. I couldn't see an issue. That said, I am thinking I will try polishing the balance pivots as a next step with a Bergeon 5482 tool. 

I'm attaching dial up and dial down pictures (dial down has the higher amplitude). These show a 120 sec period. 

I suppose I'm looking for advice on where to chase the low(ish) amplitude and differential between dial up and dial down. Any advice is greatly appreciated! 

 

 

Edited May 27, 2021 by mzinski

[Nucejoe]

Hi mzinski,

Doesn't slightly bent pivot drill a divot on cap jewel? 

Regs 

Joe

 

 

[mzinski]

40 minutes ago, Nucejoe said:

Hi mzinski,

Doesn't slightly bent pivot drill a divot on cap jewel? 

Regs 

Joe

 

 

Is that a question or the answer? 

[AlexanderToerzs]

Hi mzinski, I think it's a bit of both and yet another excellent example of nucejoe's cognitive mega powers . If you encountered a divot in the cap jewel the question is: where does it come from and could a bent pivot be the cause? This would in turn explain  the low amplitude. This may or may not lead you straight to a possible cure. Straighten the pivot or if that is not possible perhaps change the arbour.

Cheers and all the best,  Alex

[nickelsilver]

There are a number of explanations for why a cap jewel gets a divot, but the important thing is it does happen and they should be replaced. In my experience it's not related to a bent pivot. But- it's a good idea to touch up the pivot end.

 

Older Rolexes weren't known for high amplitude; 278 is already great. They also tend to pick up a few degrees after running for a few days post-service. I am curious which position is giving the 260 reading; is that with the new cap jewel (and un-retouched pivot), or the other side? Sometime a cap jewel will have a divot that just does't show up under regular examination due to lighting/angle of view/etc., but there is indeed a divot. If you can get the 260 up 10 or 15 degrees I'd say you're good to go.

[Delgetti]

I had the same problem on a rolex 1570, searched 2 weeks in the area of the balance. In the end it was a tiny piece of dirt at the bearing of the escape wheel. I don‘t claim it must be the same issue on your watch but maybe worth a look.

[Nucejoe]

8 hours ago, mzinski said:

Is that a question or the answer? 

Mainly question which found a suitable thread to jump in the midle of. 

Following you thread with interest. 

[JohnR725]

21 hours ago, mzinski said:

In addition to what I find to be low amplitude, I'm finding a frustrating differential between dial up and dial down positions - about 5 sec beat rate delta and 15-20 point amplitude delta. 

strangely enough watch companies are not concerned with your low amplitude. If you look at specifications such as the ones attached you'll see that the only concern for amplitude is not to exceed the maximum at fully wound or the minimum at 24 hours.

On the other hand watchmakers are concerned with dial-up and dial down should be basically identical on a Rolex. Variations are definitely a concern. Have you thought of changing the balance staff?

 

 

[mzinski]

Today, I have polished the pivots on the train and balance (I did not polish the fork pivots). I also re-cleaned everything associated with the train and balance and re-lubricated. 

Between dial up and dial down, the beat rate is about +/-2 seconds difference, the amplitude is the same between the two, and the beat error is +/-0.1 difference. 

Two notes: 

- The amplitude is kind of low (250-265). I'm hoping it's a little sluggish due to freshly re-lubricating and with a few hours will break in to a better amplitude. 

- The amplitude seems to vary 20 points over the course of 180-210 seconds. 

Edited May 28, 2021 by mzinski

[JohnR725]

7 hours ago, mzinski said:

The amplitude is kind of low (250-265)

it looks like polishing improve the balance pivots but you lost amplitude?

then what method you used to polish the pivots in the train

On 5/27/2021 at 4:27 PM, mzinski said:

I'll note the barrel arbor fit into the mainplate a bit tighter than I would expect/like. I have not gotten around to trying a different arbor but I will also inspect/test this.

I was rereading of the original message doesn't look like you change the barrel or the arbor so why was the arbor tight in the main plate?

then the mainspring how many different mainsprings do they have for this watch? The reason I ask is I'm looking at the original Rolex parts list and it indicates they have a standard strength and a week strength. I'm always wondering if you got the week mainspring but I doubt that other suppliers will have the variation like Rolex would?

 

[VWatchie]

According to Google translate, a divot is "a piece of turf cut out of the ground by a golf club in making a stroke." Is that the term generally used by watchmakers/repairers to describe a cap jewel having an excavation/recess in the center of the cap jewel?

[VWatchie]

On 5/28/2021 at 1:27 AM, mzinski said:

a hobbyist like myself

 

On 5/28/2021 at 1:27 AM, mzinski said:

Replacement parts have been main spring (Startime Swiss premium), stem, case clamp screw, sliding winding pinion, lower escape wheel cap jewel and shock spring (not damaged, just lost), upper balance wheel cap jewel (jewel had a slight divot in the center).

Apologies for being OT!

I'm a hobbyist as well and was under the impression that Rolex parts were 100 % restricted to authorized repairers. Your work gives me hope that I might be wrong about that. I have never serviced/repaired a Rolex (I imagine I would sweat a lot and have a hard time controlling breathing and muscles) but can you tell us a bit about where you got the parts?

Anyway, it looks to me like you did a great job with that Rolex 16610! 

[mzinski]

10 hours ago, JohnR725 said:

it looks like polishing improve the balance pivots but you lost amplitude?

then what method you used to polish the pivots in the train

I was rereading of the original message doesn't look like you change the barrel or the arbor so why was the arbor tight in the main plate?

then the mainspring how many different mainsprings do they have for this watch? The reason I ask is I'm looking at the original Rolex parts list and it indicates they have a standard strength and a week strength. I'm always wondering if you got the week mainspring but I doubt that other suppliers will have the variation like Rolex would?

 

I polished pivots with a thin paste made of 9010 and extra fine diamanté powder used in a pivot polishing tool. The. The wheels with were cleaned with Rodico, that foam-like wood, and one dip. The plate/bridges were cleaned with one dip, watch que tip, and sticky watch stick. (Forgive my lack of technical terms here)

I mentioned the brand mainspring because I was hoping someone might chime in regarding the quality/strength if it might be an issue. I’ve used them in the past without problem so I don’t suspect so but I’m not nearly that experienced. 
 

I have not gotten to the arbor and jewel setting in the main plate. That’ll be the next place I inspect and fiddle with. I imagine if it’s restricted at all there would be a drop in amplitude, right? Or maybe that doesn’t matter since the main barrel is spinning around the arbor, not the jewels the arbor sits in. 
 

[rodabod]

With older automatics, I always throughly check the centre wheel and barrel side-shake. Gently grab them and give them a wiggle with the mainspring let down. 

Edited May 29, 2021 by rodabod

[mzinski]

1 hour ago, rodabod said:

With older automatics, I always throughly check the centre wheel and barrel side-shake. Gently grab them and give them a wiggle with the mainspring let down. 

If the barrel has significant side shake, would expect to see poor and inconsistent amplitude? 

[JohnR725]

41 minutes ago, mzinski said:

f the barrel has significant side shake, would expect to see poor and inconsistent amplitude?

if you ever look at a Rolex service manual for any other service information you can see that there really quite fussed up about end shake for everything but also side shake for mainspring barrels. Unfortunately I'm not seeing any specifications or even how to check that?

On the other hand Omega has a working instruction for recycling a mainspring barrel as they call it. Which is interesting because in their service center is they just replace the entire barrel. So I have a image of what you're supposed to looking for and to see how tight the tolerances have to be.

Conceivably if the barrel gets worn too much it shifts and no longer meshes with the center which conceivably could cause a power fluctuation. Also if it twists in other words under power you look in and it's not flat it's twisted that would be bad to.

[mzinski]

So here was a fun experiment. I have another 3135 (DateJust) hanging around. It's working wonderfully, +4, 290, 0.0 in both DU and DD positions on a full wind. I decided to incrementally swap in parts to the 3135 I'm struggling with. 

First I swapped complete balances, including balance bridge: 

- Good 3135 continued to be good with the bad 3135 balance

- Bad 3135 continued to have lowish amplitude with a 210 second 20pt fluctuation

Second I swapped main barrels complete, balances returned to their respective movements: 

- Good was good

- Bad was bad

Third I swapped the great wheel (3135-330), again returning main barrels to their respective movements:

- AHA! Bad movement improved! Amplitude increased and steady more steady, about a 10 pt spread over the same interval. 

Fourth I swapped in the third wheel (3135-340), this time keeping the good great wheel in place. 

- No change in the bad movement, still decent amplitude (265-277) but still fluctuating over a 210 second period

Experiments not yet done but while I re-clean the train from the bad movement I thought I'd share some progress (I hope). 

[mzinski]

Last notes for the night: 

Full train (great, 3rd, 2nd, and escape wheels) swapped between the two movements. 
- Bad movement gets much better. Amplitude still fluctuates 10 pts between 270-280

- Good movement loses amplitude and a fluctuation is introduced, 260-275. 
 

My conclusion, I think the pivots and jewels are worn. I haven’t been able to pin point which one but rather note things incrementally improve with each wheel replacement and are best with full replacement. 
 

As I started this, the watch was beat up. I will post a picture of the dial tomorrow. The condition of the dial and the rusted stem indicate moisture made its way in at some point. Is it reasonable to assume with moisture and/or debris the pivots and jewels (maybe even teeth) were subjected to wear as a group of parts? They all wore down together? 

[rodabod]

7 hours ago, mzinski said:

If the barrel has significant side shake, would expect to see poor and inconsistent amplitude? 

It depends, but I would expect to see constantly poor amplitude as the barrel-centre wheel meshing would always be poor. It can fluctuate as the teeth engage-disengage with poor depthing. 
 

Remember that side-shake in the centre wheel affects both the barrel-centre depthing and the centre-third depthing. 
 

If you have a micrometer then measure and compare the width of the bearing edges of the pivots on the centre wheel. If this watch is jewelled at the centre wheel then it is likely that only the pivot bearing surface will have worn.