Rebanking on JLC 889/929

[Knebo]

Ok everyone!!

I managed to reduce the amplitude by about 20°.

- increasing tension on centre-seconds spring: minus 5° (more would probably be possible, but I didn't want to push it too much)
- replacing 9010 with HP1300 on the upper balance jewel setting: minus 15°.

Now, the highest amplitude I can get is 325°. No more knocking even if I try hard: full manual wind, then vigorously rotating the watch to maximize automatic winding, and then straight on the timegrapher, dial up. 

The fact that there's now an imbalance of lubrication between train side balance jewels (HP1300) and dial side balance jewels (9010) has --fortunately-- a very limited impact. The amplitude difference is only around 5° and the rate difference around 3 seconds (I didn't record the rate difference before the change of lubrication, so it may have already been the same).

I will admit that the better solution would have been a weaker mainspring. However, it's extremely hard to find a suitable one. After that, adjusting the pallet depth seemed like a more serious intervention (despite @VWatchie's kind encouragement -- I'll try it on a less valuable watch soon!!).

Finally, HP1300 certainly won't do any harm on the balance jewels. And it just "washes off" at the next service!. So no lasting changes to the movement.

I'm satisfied and will leave it at that. 

Hopefully the above impacts on amplitude will be helpful for someone down the line.

 

 

Highest I can provoke purposefully now (dial up):

After an hour of settling down (dial up):

 

Edited January 6 by Knebo

[Neverenoughwatches]

Another option to limit the amp in the horizontal positions and probably a more permanent one...to dull the pivot ends.

Endshake may have neeed reducing to go with that.

I suppose the only problem with these friction increase ideas , is that they are preventing free flow of motion. Thats something that we usually strive for but here we are encouraging friction. Is that extra amount of energy from a mainspring that is too strong, and  unrequired energy being stored within the train, it can't be stored so does that energy release itself in the form of more train wear ? Does it get pushed backwards towards the barrel ? So really the appropriate mainspring with the correct energy production was the real answer to the problem.

Edited January 7 by Neverenoughwatches

[nevenbekriev]

OK, seems all good, but one thing exists I am concerned for: How will the movement perform with this HP1300 on balance jewel outside, where it is -15degrees Celsius (let say). I just don't know the features of this oil, and would check to be sure it works.

[mikepilk]

10 hours ago, Knebo said:

Ok everyone!!

I managed to reduce the amplitude by about 20°.

- increasing tension on centre-seconds spring: minus 5° (more would probably be possible, but I didn't want to push it too much)
- replacing 9010 with HP1300 on the upper balance jewel setting: minus 15°.

Those are nice looking timegrapher plots.

The fact you got a reduction of 15° makes me think that the Omega Instruction is referring to balance jewels. I will definitely try it next time.

2 hours ago, nevenbekriev said:

OK, seems all good, but one thing exists I am concerned for: How will the movement perform with this HP1300 on balance jewel outside, where it is -15degrees Celsius (let say). I just don't know the features of this oil, and would check to be sure it works.

The operating range of HP1300 is the same as 9010. If a watch reaches -15°C whilst on a wrist, then I would think that person would not be worrying about the correct time 

[VWatchie]

12 hours ago, Knebo said:

I managed to reduce the amplitude by about 20°.

Congratulations, and I'm surprised it had such an impact. It goes to show how critical the oiling is.

12 hours ago, Knebo said:

- increasing tension on centre-seconds spring: minus 5°

Excuse my laziness, I know the information is in one of your previous posts, but is this a spring that presses against the top of the pivot (opposite the second hand) to prevent the second hand from jerking/jumping?

12 hours ago, Knebo said:

- replacing 9010 with HP1300 on the upper balance jewel setting: minus 15°.

I would have guessed significantly less than that. Very interesting!

The only possible downside to this solution is that the next watchmaker will face the same problem. In the long run, I would still encourage you to consider @nickelsilver's suggestion to adjust the pallet jewels slightly outward. It's fiddly, yes, but it's a skill worth having in your toolbox.

Edited January 7 by VWatchie

[mikepilk]

12 minutes ago, VWatchie said:

The only possible downside to this solution is that the next watchmaker will face the same problem. In the long run, I would still encourage you to consider @nickelsilver's suggestion to adjust the pallet jewels slightly outward. It's fiddly, yes, but it's a skill worth having in your toolbox.

I would change the oil as a first option. Easy to do, and saves making changes to the movement. 

As you say, adjusting the jewels isn't difficult, and you don't need any special tools. I sit the pallet on an old pocket watch plate which I heat. It can also be useful if you are lacking amplitude. I had a movement where I couldn't get good amplitude when everything looked perfect - apart from a bit too much lock. Pushing a pallet jewel in gave an extra 30° amplitude.

[VWatchie]

2 minutes ago, mikepilk said:

I would change the oil as a first option. Easy to do, and saves making changes to the movement.

Yes, it’s easier and faster, but as I see it, it’s a temporary solution. I would primarily adjust the banking/pallet jewels, as it’s a solution that lasts over time and spares the next repairer the trouble of figuring out what needs to be done to fix the problem. It also doesn’t involve any modification of the movement. The fastening mechanism is designed so that the pallet jewels can be moved back and forth, and it’s no more unusual than adjusting the length of the hairspring with the regulator arm.

[Knebo]

10 hours ago, Neverenoughwatches said:

Another option to limit the amp in the horizontal positions and probably a more permanent one...to dull the pivot ends.

I think a thicker oil is a better solution than dulling pivot ends. As you say yourself, dulling pivots is a permanent "solution". I'd rather call it "damage". A thick oil washes away and may actually reduce wear a little bit as opposed to a thinner oil.

 

 

4 hours ago, nevenbekriev said:

how will the movement perform with this HP1300 on balance jewel outside, where it is -15degrees Celsius (let say).

1 hour ago, mikepilk said:

The operating range of HP1300 is the same as 9010. If a watch reaches -15°C whilst on a wrist, then I would think that person would not be worrying about the correct time 

 I though the same @mikepilk, but didn't think of expressing it in such a funny way.

 

 

2 hours ago, mikepilk said:

The fact you got a reduction of 15° makes me think that the Omega Instruction is referring to balance jewels. I will definitely try it next time.

Yes, it makes more sense in the context of the whole sentence in the Omega document.

 

 

44 minutes ago, VWatchie said:

Congratulations, and I'm surprised it had such an impact. It goes to show how critical the oiling is.

Indeed! And considering that it's only one side of the balance, not both! But yes, the viscosity difference is huge. 150 cSt for 9010 and 1250 cSt for HP1300 (both at 20°C). At 0°C (@nevenbekriev) it's 625 cSt vs 5900 cSt, respectively.

 

 

47 minutes ago, VWatchie said:

Excuse my laziness, I know the information is in one of your previous posts, but is this a spring that presses against the top of the pivot (opposite the second hand) to prevent the second hand from jerking/jumping?

No worries! Yes and no.

- Yes, it's a spring that presses against the centre seconds pinion to prevent jerking/jumping of the seconds hand.
- But no, in this movement it's not from the top (like Omega 55x or older Rolex), but from the side. Here's a picture of the underside of the barrel bride. The green dot would indicate the place where the centre seconds pinion will be located and the green arrow the direction that the spring pushes against it. I find this solution more elegant and less tricky to adjust than the "from the top" ones. On the other hand, one has to be a bit careful when installing the bridge (see technical guide comment on Fig 7). 

 

[LittleWatchShop]

15 minutes ago, Knebo said:

I think a thicker oil is a better solution than dulling pivot ends. As you say yourself, dulling pivots is a permanent "solution". I'd rather call it "damage". A thick oil washes away and may actually reduce wear a little bit as opposed to a thinner oil.

Agreed.

[nickelsilver]

I sometimes modify the end of balance pivots, but only in certain situations. On a number of very small calibers (LeCoultre- your ears are burning), you end up with a large difference between horizontal and vertical amplitudes. Like 70 degrees. To get the vertical amplitude up to a reasonable number you end up rebanking horizontal.

 

The classic fix is to flatten the pivot ends. But, I learned from an esteemed watchmaker here a seemingly counterintuitive technique, and I was instructed by him to do it on the watches he produces: you put a slight angled flat on the pivot end with a fine Degussit stone. I thought it was a terrible idea- but it works, and I have used it with great success on a number of pieces. You do have to check that you don't throw up a burr, and if you do take it off.

 

I have the special Bergeon tool to flatten pivots, as well as a lathe and Jacot tool, and the Degussit and angled flat really gives the best results.

[Neverenoughwatches]

1 hour ago, Knebo said:

think a thicker oil is a better solution than dulling pivot ends. As you say yourself, dulling pivots is a permanent "solution". I'd rather call it "damage". A thick oil washes away and may actually reduce wear a little bit as opposed to a thinner oil.

 

I meant its only a permanent solution in the fact that it will stay as is, where as oil may change over time. It can of course be rectified without changing the endshake again.  Its a fairy well recognised idea, I've read it a few times and mentioned here and other forums. I did try it once on a scrap movement in a rather rough way, the effects were quite devastating to the amplitude

If you want to learn something....if you want to find things out...then you have to do something that gives you an answer....you have to experiment

3 hours ago, mikepilk said:

The operating range of HP1300 is the same as 9010. If a watch reaches -15°C whilst on a wrist, then I would think that person would not be worrying about the correct time 

So you don't store your watches in your fridge Mike ? For safekeeping against theft or fire risk. How very odd, it was the first place I thought of when planning my home security

And is probably why I'm always late for everything I do

1 hour ago, Knebo said:

Indeed! And considering that it's only one side of the balance, not both! But yes, the viscosity difference is huge. 150 cSt for 9010 and 1250 cSt for HP1300 (both at 20°C). At 0°C (@nevenbekriev) it's 625 cSt vs 5900 cSt, respectively.

 

I think @nevenbekrievmade his point then, the UK has had quite a few 0°C this year, quite tolerable really....for me anyway. At 0°C HP1300 has 3x the consistency of honey and half that of treacle at normal room temperature.  If the balance gets anywhere near 0°C then it ain't moving. My next experiment is to oil bal cap jewels with honey . 

[mikepilk]

46 minutes ago, Neverenoughwatches said:

I think @nevenbekrievmade his point then, the UK has had quite a few 0°C this year, quite tolerable really....for me anyway.

But the watch on your wrist be closer to body temperature than ambient.

[Neverenoughwatches]

14 hours ago, Knebo said:

I managed to reduce the amplitude by about 20°

Whats the difference between horizontal and verical positions? I thought the thick oil would kill the vertical once it reaches the jewel hole. 

[mikepilk]

1 hour ago, nickelsilver said:

you put a slight angled flat on the pivot end with a fine Degussit stone. I thought it was a terrible idea- but it works, and I have used it with great success on a number of pieces. You do have to check that you don't throw up a burr, and if you do take it off.

You mean the whole end is angled like this ?

[Neverenoughwatches]

2 minutes ago, mikepilk said:

But the watch on your wrist be closer to body temperature than ambient.

Body heat would certainly be a factor Mike...thats why I said IF the balance gets near 0°C . Just depends what your doing......maybe Nev think Knebo has ice-sculpture for a hobby

5 minutes ago, mikepilk said:

You mean the whole end is angled like this ?

That's just way to wierd to be true, the balance staffs on my bench are shaking in their regulator boots.

[nickelsilver]

29 minutes ago, mikepilk said:

You mean the whole end is angled like this ?

Exactly. Seems crazy but it works.

 

A funny thing with truly flat pivots- if there is any contamination of the oil in the balance jewels, with particles, one will inevitably make its way to the pivot, get under it, and act like a ball-bearing, increasing the amplitude. Obviously we imagine that our jewels and oil are always spotless, but this weird technique also precludes any issue there.

 

A more elegant solution is what is referred to as "Daniels" cap jewels (around here at least). The cap jewel has a slight concave area, a little offset from center. This forces the pivot against the hole jewel in the horizontal, dropping the amplitude a bit. I worked on a series of watches years ago where this was an option to get the amplitudes closer. In a more extreme example, Vulcain at one time had cap jewels that were conical, again pushing the pivot against the hole jewel. Don't lose one of those!

 

Found an ad for the Vulcain "Exactomatic"

 

Edited January 7 by nickelsilver

[Knebo]

2 minutes ago, Neverenoughwatches said:

maybe Nev think Knebo has ice-sculpture for a hobby

56 minutes ago, Neverenoughwatches said:

My next experiment is to oil bal cap jewels with honey . 

57 minutes ago, Neverenoughwatches said:

So you don't store your watches in your fridge Mike ? For safekeeping against theft or fire risk. How very odd, it was the first place I thought of when planning my home security

And is probably why I'm always late for everything I do

Man, you're on fire today . Cracking me up 

 

 

 

3 minutes ago, nickelsilver said:

Exactly. Seems crazy but it works.

 

A funny thing with truly flat pivots- if there is any contamination of the oil in the balance jewels, with particles, one will inevitably make its way to the pivot, get under it, and act like a ball-bearing, increasing the amplitude. Obviously we imagine that our jewels and oil are always spotless, but this weird technique also precludes any issue there.

 

A more elegant solution is what is referred to as "Daniels" cap jewels (around here at least). The cap jewel has a slight concave area, a little offset from center. This forces the pivot against the hole jewel in the horizontal, dropping the amplitude a bit. I worked on a series of watches years ago where this was an option to get the amplitudes closer. In a more extreme example, Vulcain at one time had cap jewels that were conical, again pushing the pivot against the hole jewel. Don't lose one of those!

very interesting!! Is that "Daniels" as in "George Daniels"?

[Neverenoughwatches]

4 minutes ago, Knebo said:

Man, you're on fire today . Cracking me up 

 

Lol  If you've laughed..then I'm happy  

[nickelsilver]

9 minutes ago, Knebo said:

very interesting!! Is that "Daniels" as in "George Daniels"?

Yes, he shows the technique in Watchmaking. Pain in the rear to put the little dish in there uniformly; we would get an assortment that were all a little different, and you had to pick and choose to find a pair that worked equally with the appropriate amplitude drop.

[Neverenoughwatches]

So @Knebo what you doin for your next trick ? ......your thread has practically practically taken over the forum today

Note. Two practicallys are slightly lesser than one practically....as there has been some minor discussions going on elsewhere behind the scene

[Knebo]

34 minutes ago, Neverenoughwatches said:

as there has been some minor discussions going on elsewhere behind the scene

You mean there's a secret society here that I'm not a part of  ?? 

32 minutes ago, Neverenoughwatches said:

what you doin for your next trick ?

to get everyone going, I should probably start a topic about lubrication and/or epilame  ("HP1300 and epilame in the keyless works is better than using grease" )

 

 

41 minutes ago, nickelsilver said:

we would get an assortment that were all a little different, and you had to pick and choose to find a pair that worked equally with the appropriate amplitude drop.

where was that? at watchmaking school?

Edited January 7 by Knebo

[Neverenoughwatches]

14 minutes ago, Knebo said:

You mean there's a secret society here that I'm not a part of  ?? 

If you can perform the handshake then you're in..otherwise there's an exorbitant joining fee. I'd give it a miss if I were you... its full of boring old farts, i learned the handshake by accident and now they won't let me leave

20 minutes ago, Knebo said:

to get everyone going, I should probably start a topic about lubrication and/or epilame  ("HP1300 and epilame in the keyless works is better than using grease" )

 

Noooo, JohnR did that to me only yesterday or the day before ? He challenges my brain in ways it can't cope with, I end up having to blag my way out of a question with him....nooooo please not again.

[nickelsilver]

25 minutes ago, Knebo said:

where was that? at watchmaking school?

This was on Christophe Claret repeater movements. They were a super pain to regulate; funnily enough the tourbillon version was much easier to regulate.

 

 

[nevenbekriev]

8 hours ago, nevenbekriev said:

OK, seems all good, but one thing exists I am concerned for: How will the movement perform with this HP1300 on balance jewel outside, where it is -15degrees Celsius (let say). I just don't know the features of this oil, and would check to be sure it works.

Once I had problems with some old oil: I had good amplitude when the room temperature was normal, but in the morning (winter time, my 'shop' is in a cabin) the amplitude was bad and slowly recovered by heating the room.

[Knebo]

17 minutes ago, nickelsilver said:

This was on Christophe Claret repeater movements. They were a super pain to regulate; funnily enough the tourbillon version was much easier to regulate.

 

 

Wow. These two sentences subtly show the extraordinary level you are at 

Edited January 7 by Knebo