What causes an Elgin P/W

[Wayne C. Anderson]

roller jewel to jump out of alignment with levers fork slot? I have found several 18size Elgins that the roller jewel is like that, and when I re-install the balance in the correct position, the watch runs..could that indicate the the banking pins are not properly adjusted?
And if the banking pins are not properly adjusted, would they be moved in or out?
Thanks for any information/advice.

[Wayne C. Anderson]

roller jewel to jump out of alignment with levers fork slot? I have found several 18size Elgins that the roller jewel is like that, and when I re-install the balance in the correct position, the watch runs..could that indicate the the banking pins are not properly adjusted?
And if the banking pins are not properly adjusted, would they be moved in or out?
Thanks for any information/advice.

[xylo]

If I understand the problem correctly you are speaking of what is called "Overbanking", which is most commonly caused by a sudden jar to the watch causing the balance to advance forward more than it should, causing the roller jewel to lock beyond the fork slot unable to return to its original position.

I have bought a number of watches off of eBay with this problem and have been delighted when this was the only problem encountered.

There are other causes for overbanking, such as the balance being out of beat, banking pins too far apart, too strong of a mainspring, just to name the most obvious.

I'm not sure I have explained it properly, but hopes this helps.

[Jerry Treiman]

Banking pins are only one of several possible adjustments (or mis-adjustments) that could be involved, but this would be the last thing I would try to adjust unless I had good reason to believe the pins had been moved by someone else. More likely is a problem with the guard finger or pivots that are too small for the hole jewels allowing too much side shake in the balance. If you modify the banking that affects other escapement actions. Other, more qualified watchmakers may have additional comment.

[Wayne C. Anderson]

XYLO
Your description "If I understand the problem correctly you are speaking of what is called "Overbanking", which is most commonly caused by a sudden jar to the watch causing the balance to advance forward more than it should, causing the roller jewel to lock beyond the fork slot unable to return to its original position." appears to be exactly correct.
When I re-install the balance wheel correctly (with the roller jewel in the fork slot) they run with no problem - and I always check for 4 positions to verify (running not accuracy). It appears that the fork slot is not bent open or otherwise damaged, so perhaps its just that someone dropped the watch and it jumped out of the slot. Thanks

Jerry
Thanks


[This message has been edited by waynea38 (edited 07-30-2002).]

[This message has been edited by waynea38 (edited 07-30-2002).]