Overbanking at Low Amplitude

[jdrichard]

All right here’s my question. I have a very old Waltham, Pocket Watch, full plate. It has a straight pallet fork. The watch is running wonderfully until it gets to the very end of its power. At this point it seems to end up with the impulse jewel on the wrong side of the pallet fork; typically called overbanking by many. My question is, do I adjust the banking pins to prevent this? Or, is there another issue that could cause this like the position of the dart on the pallet, fork? I’d rather not dive into, adjusting the dart, as the watch runs perfectly right now, and this problem only exist at the very end of its power. I am fixing this watch for a customer, and this one is stumping  me.

Edited February 19, 2024 by jdrichard

[JohnR725]

4 minutes ago, jdrichard said:

banking pins

the banking pins are typically used for the fork horn clearance. The guard pin is what you want to look at but people playing with the banking pins will screw up the guard pin clearance also. so basically have to make sure that the banking pins our where there supposed to be usually people don't play with the guard pin but usually is not 100% and is bound to be somebody who decides to play with it. I would check your banking pins first you might be lucky.

Then there is the other little problem vintage hopefully nobody has been mixing and matching balance components. I assume this is a single roller? single roller tends to be well can have more issues which is why they abandoned it but not soon enough.

[jdrichard]

17 minutes ago, JohnR725 said:

the banking pins are typically used for the fork horn clearance. The guard pin is what you want to look at but people playing with the banking pins will screw up the guard pin clearance also. so basically have to make sure that the banking pins our where there supposed to be usually people don't play with the guard pin but usually is not 100% and is bound to be somebody who decides to play with it. I would check your banking pins first you might be lucky.

Then there is the other little problem vintage hopefully nobody has been mixing and matching balance components. I assume this is a single roller? single roller tends to be well can have more issues which is why they abandoned it but not soon enough.

Thanks for the advice. So what I’m gonna try first is to adjust the banking pins to make sure that I retain the amplitude of the watch and that the pallet fork is not so far over on one side to allow the overbanking to occur. I have noticed that When the impulse outside the horns of the pallet fork, it’s always on the right side when looking straight down at the pallet Fork. Which means that the impulse Jewel ends up on the left side of the horns each time. This could mean that the left side banking pin needs to be adjusted.

33 minutes ago, jdrichard said:

Thanks for the advice. So what I’m gonna try first is to adjust the banking pins to make sure that I retain the amplitude of the watch and that the pallet fork is not so far over on one side to allow the overbanking to occur. I have noticed that When the impulse outside the horns of the pallet fork, it’s always on the right side when looking straight down at the pallet Fork. Which means that the impulse Jewel ends up on the left side of the horns each time. This could mean that the left side banking pin needs to be adjusted.

Watch Overbanking Question
https://youtu.be/wTg8nrZyVUY