What is too much wear in a jewel hole ?

[mikepilk]

I have an Omega 455 (I hate it !) which I work on when I've no other watches to play with.

Being a small 'ladies' movement, 16mm dia, automatic + sweep second, it's all very tiny and fiddly. The hairspring is just too tiny to work on.

The balance is only 6mm diameter, so everything needs to be spot on to get good amplitude - which I aren't.

I've had this thing apart so many times looking for problems. I'm working through every pivot and jewel to find out where I'm losing power.

This is the lower escape wheel jewel. Is that too much play, robbing me of amplitude ?   I think probably yes.

What is the general consensus on jewel hole wear - is there an industry standard recommendation ( @nickelsilver, @JohnR725, @praezis )  ?

Maybe half the pivot width ?  

 

[JohnR725]

  On 5/4/2023 at 9:49 AM, mikepilk said:

so everything needs to be spot on to get good amplitude - which I aren't.

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I know it's the obsession of this group but is amplitude really that important more important than keeping good time? What sort of amplitude are you aiming for for instance there is the timing specs from Omega what sort of timing amplitude are they expecting? Notice there only concerned about the amplitude at the end of 24 hours  170°. They are in real life concerned about timekeeping not amplitude.

another problem conceivably could run into is something this tiny is lubrication will be critical. I remember when I was in school the instructor is using an organic oil for the super tiny ladies watches. From the lubrication specifications I've seen usually organic oils do have better properties for reducing friction but consider the worse it everything else.

then yes I went back and looked at your video I think it looks better than the Rolex video that someone gave me as it was flopping around considerably more than this. Oh and then there is the other little problem jewel wearing out or pivot wearing out?

 

[mikepilk]

  On 5/4/2023 at 11:48 AM, JohnR725 said:

I know it's the obsession of this group but is amplitude really that important more important than keeping good time? What sort of amplitude are you aiming for for instance there is the timing specs from Omega what sort of timing amplitude are they expecting? 

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It's no longer an obsession for me . For older watches which have some obvious wear, I would like to see about 240° (or even 220-230° if it's 170° after 24h). But this was struggling to get 200°.

  On 5/4/2023 at 11:48 AM, JohnR725 said:

another problem conceivably could run into is something this tiny is lubrication will be critical. 

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Too true. I recently cleaned another small Omega Cal 620 which was also showing signs of wear. I was happy to see about 240° when I assembled it. But when I oiled it, using 9010 throughout the gear train, I lost 20-30°. I think I was too liberal with the oil.

I bought another 455 to use as a donor, but that seems to have wear in the same places. This one may have to go back on the shelf.

[praezis]

Hi,

I don't know worn jewel holes, just damaged ones. But I knew many worn pivots.

Usual sizes are: 
pivot under 0.2mm: jewel hole = pivot plus 1/100 mm
pivot 0.2mm and more: jewel hole = pivot plus 2/100 mm

Frank

[mikepilk]

  On 5/4/2023 at 12:14 PM, praezis said:

Hi,

I don't know worn jewel holes, just damaged ones. But I knew many worn pivots.

Usual sizes are: 
pivot under 0.2mm: jewel hole = pivot plus 1/100 mm
pivot 0.2mm and more: jewel hole = pivot plus 2/100 mm

Frank

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I think you might be right looking at it, more likely a worn pivot. I have no means of measuring the hole,  though I could probably do it with the microscope. And only have a normal digital micrometer - tricky and dangerous to measure pivots. 

[Nucejoe]

Any imperfection is unacceptable and should be replaced with new jewel. Pivots too  must be repaired or replaced.

 

 

[JohnR725]

  On 5/4/2023 at 2:48 PM, Nucejoe said:

new jewel. Pivots too

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the problem still is which is it? May because it's easier to do just change the escape wheel  and perhaps a new pallet fork.

[mikepilk]

  On 5/4/2023 at 5:01 PM, JohnR725 said:

the problem still is which is it? May because it's easier to do just change the escape wheel  and perhaps a new pallet fork.

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I've spent way more on this watch than it's worth. I don't want to spend any more.

I've swapped the escape wheel from the one from the parts movement. There's less play. 

[Nucejoe]

  On 5/4/2023 at 12:14 PM, praezis said:

I don't know worn jewel holes, just damaged ones. But I knew many worn pivots.

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Jewels aren't 100% impenetrable. I have seen  dimple drilled into end stone by damaged balance pivot, where a piece of pivot-end had chipped off, the half still intact had done drilled the dimple.  

So I guess we can't rule out wear on jewel hole by worn pivots.

 

 

 

[JohnR725]

which is more likely to wear out a sapphire jewel or a steel pivot? What about a brass escape wheel in a clock versus the steel pallet which is more likely to disintegrate with time? In the case the clock the brass escape wheel can get embedded with dust floating around in the air and the lubrication together make a really nice grinding compound and over years of use will grind the steel pallets. In the case of sapphire if the balance pivot has rust on it that can make a really interesting grinding compound. Although sapphire is a tough time surviving against impact damage. Especially at the balance wheels big and heavy it can really destroy jewels.

[mikepilk]

I have seen jewel holes out of round which have definitely been worn away. As @JohnR725 says, a bit of rust and dried oil makes a good grinding paste.

[praezis]

  On 5/4/2023 at 10:36 PM, mikepilk said:

a bit of rust and dried oil makes a good grinding paste.

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Not yet. You need something harder than ruby (or at least same hardness) in that paste. 

But not too far away now, as people use diamond for grinding each and every thing.

Frank

[mikepilk]

As @Nucejoe says, we have all seen wear in cap stones from pivots - or were they manufactured to have a dimple in?  Jewel hardness is 9, hardened steel 7-8, so I don't know why it happens.

[mikepilk]

I've had enough of this darn movement 

Worked my way through again, checking everything. There was a bit too much play in the lower barrel arbor hole, so I close it a bit. Gear train running sweetly, and the balance when blown.

Cleaned and assembled again (7th or 8th time) - seeing 250° amplitude. Great ! 

Oil the gear train with a small amount of 9010, and the pallets with 9415

Result : Amplitude 190°  WTF   (This happened the last time too)

It should improve a bit overnight, but I can't see how light oiling can lose 60° amplitude. 

Edited May 9, 2023 by mikepilk

[nickelsilver]

It should indeed come back up after a day or so, but maybe not all the way. I know certain LeCoultre movements, the really tiny ones, don't like 9415. Similarly to your Omega, often running quite well with the escapement dry, then big drop in amplitude with 9415 and not a full recovery. A very, very small amount of 9010 works great. These are smaller than your Omega, but certain movements are just really sensitive.

[JohnR725]

  On 5/9/2023 at 4:06 PM, nickelsilver said:

9415. Similarly to your Omega, often running quite well with the escapement dry, then big drop in amplitude with 9415 and not a full recovery. A very, very small amount of 9010 works great

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somewhere else on this group recently several people voiced their unhappiness with 9415 and there were using something else. This is where probably 941 would be a better choice but it would be another bottle of oil.

  On 5/9/2023 at 4:06 PM, nickelsilver said:

often running quite well with the escapement dry

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  On 5/9/2023 at 3:51 PM, mikepilk said:

but I can't see how light oiling can lose 60° amplitude. 

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by the way do you like the oilier pallet fork pivots? We know that lubrication reduces friction and it would stand the reason that lubricating the pallet fork pivots would be a good thing but we don't do it typically why? All lubrication has a certain degree of dampening and a braking effect. I'm not a physicist or a scientist but all lubrication as undesirable property's. So yes reduces friction that means we should use it on the pallet fork but when we do we see a loss of amplitude usually well sometimes dramatically.

how about a quick review of cleaning a lubrication? Specifically how do you clean the watch do you ever try to polish the pivots or use anything on the pivots to clean them. Then all the lubrication's you using.

[mikepilk]

  On 5/9/2023 at 5:00 PM, JohnR725 said:

how about a quick review of cleaning a lubrication? Specifically how do you clean the watch do you ever try to polish the pivots or use anything on the pivots to clean them. Then all the lubrication's you using.

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I pegged all the jewels and cleaned everything again in the ultrasonic - Elma WF Pro, 2x Elma Suprol rinses, and 30s IPA.

All the pivots look OK - I push them in to the edge of pith wood before the ultrasonic. Some are a bit worn, but I've used the best from the two movements I have.

The gear train runs quite freely, and the balance swings nicely when blown with the puffer. I was happy with the 250° amplitude before I started oiling - expecting it to go up when I oiled the pallet jewels, not down !

I have oiled pallet pivots - but only to try to stop rebanking. I thing Omega recommend it ?

[JohnR725]

  On 5/9/2023 at 5:20 PM, mikepilk said:

pivots

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one of the reasons I was asking was because some people actually polish their pivots with something I try not to pay attention to this. Why sometimes get concerned with the obsession of polishing things in strange fashions might actually cause more harm that good. But it looks like you're doing fine

I would try the 9010 on the pallet fork. Which means you have to take it out and rinse it off before you do what I try oiling the pivots and seeing what happens. As I said all oils can have a dampening effect the pallet forecast to move really really really fast and you can't have oil holding it in place. So yes the choice of lubrication's for some watches is critical. Unless you have some 941 just go with the 9010 and see what happens to your amplitude. Oh and then there's the other little thing. I know somebody used to work at Swatch group if they had issues it's a brand-new escape wheel and pallet fork. Like we all have the luxury of a back room with infinite supply of things like that. One of the reasons they change the escape wheel and pallet fork to brand-new is the escape wheel is lubricated was something that got washed off long time ago on yours. So the actual recommendation is if that is washed off it's basically a lubrication with a little bit of  my dictation software really hates me today so I can't say the word it say dry dark lubrication Molly lube close enough. That's actually on all the factory new watches which is why if you're looking at a watch and wonder what the dark stuff is that's what it is but it washes off in the cleaning machine. So the recommendation is to replace the escape wheel with a brand-new one.

[rehajm]

  On 5/4/2023 at 5:10 PM, mikepilk said:

I've spent way more on this watch than it's worth.

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Evergreen statement in my case.... . Ever hear of the Sunk Cost Fallacy? Haha- me neither...

...still cheaper than a boat...usually...

[VWatchie]

  On 5/4/2023 at 9:49 AM, mikepilk said:

What is the general consensus on jewel hole wear - is there an industry standard recommendation ( @nickelsilver, @JohnR725, @praezis )  ?

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I asked myself that question many times until I saw Kalle Slaap from Chronoglide show an amazingly simple and effective way to determine if the side shake is correct. 

 

[Klassiker]

Time to up the mainspring power?

[mikepilk]

  On 5/12/2023 at 5:55 AM, Klassiker said:

Time to up the mainspring power?

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That's one option, but as I said, I don't want to spend anymore. I bought this ladies watch as it was cheap and something to play around with. I've spend 3x more on parts than what I paid for it.  I'm now seeing over 240° amplitude, so I'm going to sell it (no doubt at a loss)

[VWatchie]

  On 5/12/2023 at 7:54 AM, mikepilk said:

I'm now seeing over 240° amplitude

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Fantastic! 

  On 5/4/2023 at 9:49 AM, mikepilk said:

This is the lower escape wheel jewel. Is that too much play, robbing me of amplitude ?   I think probably yes.

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I too would say yes. Did you do anything about it? Wear on the hole and/or the pivot?

[mikepilk]

  On 5/12/2023 at 8:00 AM, VWatchie said:

Fantastic! 

I too would say yes. Did you do anything about it? Wear on the hole and/or the pivot?

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I swapped the wheel for the one in the spare movement. It was less worn.

I'm still not sure if jewel wear is a problem or not. They shouldn't wear, but we've all seen wear in cap jewels. 

[VWatchie]

  On 5/12/2023 at 9:43 AM, mikepilk said:

I'm still not sure if jewel wear is a problem or not. They shouldn't wear, but we've all seen wear in cap jewels. 

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Interesting question and now that you mention it I don't think I've ever heard anyone mention jewel-bearing wear. Yes, cap jewels for sure and I've seen it several times (the famous dimple). I'm not sure, and I could be imagining, but I think I've seen jewel holes slightly oval-shaped. Could that be a worn hole? 

What I've done when I've seen excessive side shake is burnish the pivot (slightly Coca-Cola bottle-shaped pivot) and replace the jewel.