Internet Horology Club 185
Elgin 12s with new mainspring won't run

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https://ihc185.infopop.cc/eve/forums/a/tpc/f/3426047761/m/1733990287

April 04, 2014, 13:14
Dave Turner
Elgin 12s with new mainspring won't run
Serial number 20582033 - used white alloy spring #2339 from Brian C.

I've had this thing apart about six times now.
It runs great if I apply a slight pressure to the mainspring barrel.
Installed a new alloy spring, and it winds as it should to full wind. Sets as it should also.

I have noticed that the tab extending through the barrel protrudes slightly on the bottom, and wonder if it might be dragging on the plate. Don't think this is the problem as the barrel does have some clearance and rocks on it's pivot somewhat.

Can't see any other possibilities as to why this watch will not run!




Dave Turner
April 04, 2014, 15:23
Paul D. Trombley
So, it winds up, the spring is hooking up in the barrel and is taking a full wind, but binds the drive train somehow???

I would suggest revisiting jewels and shafts/pinions to see if it is an alignment issue. I don't see the third wheel pinion peaking up... this could be a 2nd/3rd wheel meshing issue. Free spins nice, but doesn't like the torque under full spring loading.

I would pull the train bridge, reinspect all shafts and wheels, then go back together again.
April 04, 2014, 15:43
Dave Turner
Thanks for the suggestions.
This watch has acted the same way since I started on it. drive train is free, plenty of kickback.
The old spring was not broken, and after installing the new spring there is still no difference.


Dave Turner
April 04, 2014, 17:07
Paul D. Trombley
Wrap it in 20's and send it to an Able watch maker???
April 04, 2014, 17:24
Dave Turner
That's a thought, but this is a $10 watch!! Wait a minute, I put $18 in the mainspring. Confused


Dave Turner
April 04, 2014, 17:44
David Abbe
I agree that something is binding up. Take out the balance and pallet fork and try "free spin under power" of the mainspring driven wheel train. If that works, the watch should run.

If it does not,the Mainspring arbor holes in both plates, the barrel and barrel cover may well need re-polishing and lubing.
April 04, 2014, 18:59
Dave Turner
Thanks Dave,
Sounds like a plan. I'll try it.


Dave Turner
April 04, 2014, 20:44
Paul D. Trombley
Dave,

Did you say it was doing this before you started the project?
April 04, 2014, 21:20
Dave Turner
Yea, as best I can remember it was.
I think you all have me back on the right track though.
I took the balance and pallet fork out as Dave suggested. And it freewheels sporadically.
ie: must have some dirty or rough pivots somewhere. Back to basics. Be sure everything is clean and smooth.
Mainspring winding is kinda iffy too. Looks like I'm going to have to take that apart again too. It's a real pain to try and get that tab in the slot on the outer barrel edge!!!

I'll tear it down and clean it again, being careful to polish all the pivots this time.

It ran so freely when it did run that I thought sure this one would be quick and easy.


Dave Turner