Escapement Trouble- Cal. 354

Hello,

Today I am dealing with what I believe are some significant escapement problems, with a bodge fix previously attempted. I’d like to get to the bottom of what is going on here, but I will no doubt need some help from those more knowledgable than me.

This cal. 354 came to me in a pretty sorry state, with severe wear in the barrel arbor bushing, center wheel/bushing, gross overoiling, and all number of watchmaker’s scratches and marks scattered about. The issue I’m currently dealing with concerns the escapement.

I noticed upon dissasembly that the banking pin on the exit side was severely bent outwards, such that the pallet fork had an absurd amount of drop on that side and very high lock. The entrance side seemed okay to me on both counts. Amplitude and rate were terrible, and even with the impulse jewel pretty well centered the watch was exhibiting 8.9+ms beat error.




I knew that whatever the real issue was, the bent banking pin was not fixing it, so I decided to straighten it back up and see what happens. I did not bring it fully straight at first, maybe 85% of the way. Amplitude, beat error, and rate were significantly improved, but I was still showing 2.2-3 degrees of beat error and lock/drop were still excessive on the exit side.



I kept bringing the pin in until drop/lock looked correct to me. I stopped short of allowing the escapement to fully bind and bringing it back out. I am okay with a slight error here, as long as the function of the escapement is not seriously impacted.


Unfortunately I am now seeing slightly higher beat error, lower amplitude, and the pallet fork horns are contacting the roller table in all positions but DD.. It seems to me that the main issue is now somewhere else, so I checked the pallet fork and escape wheel endshake. By my estimation, one or both are quite bad.


This seems to correlate with the oil pattern on the pallet fork (yes, I realize this is too much oil, I’ll do better next time.)



I looked very carefully at the pallet fork pivots and they did not appear bent to me, but I’m only looking with 20x magnification so it may not be enough. It seems more likely to me that the issue connected to the end shake/alignment of either the escape wheel, pallet fork, or both.

I suppose I could bring the banking pin back out enough to get a running watch and forgo this mess, but I’d really like to get to the bottom of this if I can. I realize this is more advanced stuff and there are a lot of moving parts (no pun intended) so if more photos or videos are necessary to get the full picture please let me know.

Thank you very much in advance!

End shake on both appears to be excessive, but on the pallet fork you need to lift as close to the pivots as possible.

Fortunately this is easy to adjust, but you need to be sure which jewel needs to be moved in what direction, in order to avoid the sort of interference you have now.

In terms of the escapement adjustments, unfortunately many people solve the “problems” they find by bending the banking pins instead of adjust the pallet fork jewels. So correct the banking pins first, then if needed adjust the depth of the pallet fork stones.

Thanks as always!

To be sure I understand, you suggest banking to the drop (straighten the pin until the escapement locks, then backing up), then evaluating pallet fork endshake more carefully, and assuming it is actually excessive, working out which direction the pivot stones need to move?

Also, when you say end shake is excessive are you referring to the pallet fork only, or the escape wheel too? If the escape wheel is out, which one should be adjusted first?

End shake is a stand alone adjustment, by moving the pivot jewels. The banking pins have nothing to do with that.

Both are excessive from what I see. What jewels to adjust has to be determined by looking at clearances. If as you say the pallet fork is already contacting the roller table, you need to fix that first then adjust the others after accordingly.