How much 941 is enough?

jplotkin

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Here's a photo and -- more useful yet -- a video showing the interaction between the pallet jewel and the ratchet-tooth escape wheel (English movement), after cleaning and applying Moebius 941 to the pallets.

The movement is running beautifully. But, for experts out there, is this a correct amount of oil on the pallets, or too much?

Screen Shot 2021-01-26 at 11.43.38 AM.png
 

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gmorse

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Hi Joshua,

That doesn't look too bad, but it's hard to keep the oil in place on this type of escape wheel. 941 is a liquid oil which can migrate, whereas 9415 is a type of grease. This stays put better, because it's thixotropic, meaning that it only becomes a liquid when the tooth makes contact with the pallet and reverts to a grease afterwards. Although Moebius specify it for higher beating escapements, (21,600 and upwards), it seems to do a good job on any type, even verges.

Regards,

Graham
 

jplotkin

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Are club-toothed escape wheels better at keeping 941 in place, by the way?

I presume the risk of spread is that the oil might move to the pinion, or even splatter to the hairspring? And then attract dirt?
 
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gmorse

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Hi Joshua,

Are club-toothed escape wheels better at keeping 941 in place, by the way?

I presume the risk of spread is that the oil might move to the pinion, or even splatter to the hairspring? And then attract dirt?
There's more room on the acting surfaces of a divided lift escape wheel than on a ratchet tooth type, but on both types the tooth tends to scrape the oil off the pallet. This is the age-old problem of keeping the right amount of oil in just the right place that led George Daniels to develop the coaxial escapement.

The risk of the oil spreading to where it isn't wanted is certainly greater if there's too much of it, and if there's too little, the risk is wear and poor amplitude; you can't win! Breguet is famously reported as saying that if he was provided with a perfect oil, he could make a perfect watch.

Regards,

Graham
 
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jplotkin

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I didn't realize this was the motivation behind Daniels' invention.

Regarding the co-axial: the three pallet jewels and the very tight tolerance with the escape wheel(s) teeth would certainly reduce friction, but would also seem to make the entire escapement susceptible to shock, locking the fork in the wrong position. I'm sorta amazed it works at all, on the wrist..
 

John Runciman

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The movement is running beautifully. But, for experts out there, is this a correct amount of oil on the pallets, or too much?
Unfortunately this is not a simple question.
Moebius specify it for higher beating escapements, (21,600 and upwards), it seems to do a good job on any type, even verges.
Originally when it came out the recommendation was for higher frequency watches. Then in the tech sheets you would see that. But soon you'd see in either or and now it's just the 9415 typically.

If your watches running beautifully then it's fine.

If you want to get obsessed about it I'm attaching a PDF.

Starting on PDF page 13. Unfortunately we do not have any Lubrifar And if we did it was very expensive. It's really 9010 with some molybdenum-bisulphide (black) and oil 9010. It's applied at the factory which is why we don't have it. In one of the catalogs there was a setup that you could get with a spray can it must've been outrageously expensive. Which means we can skip over these pages. Basically only find it on new watches

then we get to the next complication if you want your lubrication to stay in place you use epilam. It's a surface treatment to keep the lubrication from spreading which is why you can use an oil. But you also noticed they talk about testing without that.

Now we have an interesting problem? On modern watches late and he goes super minimalistic especially with 9415 because as a grease it can be sticky if it's too heavy of encoding. Especially with the modern escape wheel where the edge is been reduced in surface contact versus your watch or vintage with a flat surface. So they worry about loss of amplitude. On the older vintage it shouldn't really apply at all.

So the problem becomes nobody is running testing on vintage watches to see what the proper amount of lubrication is. If it's running beautifully it's fine if it continues to run beautifully for several years it's really fine and it's not a problem at all. But if you want to get obsessed you can fall the technical sheets which do not apply to vintage so you're screwed.
 

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Al J

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I didn't realize this was the motivation behind Daniels' invention.

Regarding the co-axial: the three pallet jewels and the very tight tolerance with the escape wheel(s) teeth would certainly reduce friction, but would also seem to make the entire escapement susceptible to shock, locking the fork in the wrong position. I'm sorta amazed it works at all, on the wrist..
Small tangent here...

An escapement without oil was the motivation, but in practice the escapement does require oil. Depending on the type of co-axial escapement (3-level or 2-level) there are either 10 specific points to oil or 30 specific points in the escapement. Has to be done under a microscope with very small quantities of oil.

Early versions (the 2-level) were fraught with problems, so they were abandoned and now the 3-level is used exclusively by Omega.

Wear in the escapement can also be a major issue, as I've seen a number of worn co-axial wheels...example below:



I'll service them, but I won't own one...

Cheers, Al
 
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jplotkin

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Thank you for the detailed PDF, John. Even the diagrams on pages 15 are very useful, in addition to the technical measurements (on modern movements).
 

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