I am new to this forum and still quite inexperienced when it comes to diagnosing faults. I was hoping someone could point me in the right direction for tracking down the cause of low amplitude.
Some Background: I recently acquired a 12s ‘Delmark’ branded pocket watch was not running. It had a broken mainspring, and as I couldn’t find any model number or useful information on the watch I replaced the broken spring with the closest available silver alloy equivalent. After manually cleaning and reassembling the movement I found it to have very poor amplitude around 110 degrease. I disassembled the movement and inspected the balance, staffs, jewels and train gears and didn’t find any obvious problem. With just the balance installed and given a slight perturbation it smoothly oscillates for several seconds without any sign of excess friction. I have also installed each of the train wheels individually and looked at the end play with my 10x loupe but wasn’t really able to distinguish excessive play (although I have no real experience here). There also doesn’t seem to be excessive lockup in the escapement, and the banking pins are nonadjustable. Also, the balance cock rests directly between the banking pins when the mainspring is let down.
It seems like there must be a glaring problem I am missing. Does anyone have any thoughts?
This was my father's Gotham watch that my mother gave to him in 1942. It's an automatic, and although he stopped wearing it in the early 60's (he passed in 2000), it still runs with decent amplitude. I'd like to disassemble, clean, lube, and adjust it, but I don't know how to remove the stem to get at the movement. In the "Gotham 3" photo you can see the movement coming slightly out of the case, but I have not figured out how to release the stem to remove the movement completely.
I am working on a beautiful 21 Jewel Gold Splashed Elgin movement and it is running way to fast, past the adjustment leaver. So the question is, do I just unscrew the meantime screws on the balance (2 Screws, equal turns) or do I also do the Quarter Screws?
The balance is in beat after I adjusted the collet (approx .5 ms).
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