Posted August 17, 2010 17:23
I recently serviced this watch and I thought the repair was quite interesting, so I thought that I would share it.
The watch is a Hamilton electric, and it was sent to me as a non runner. The reason was obvious at first, since the contact and trip wires were far away from where they belonged.
I cleaned the watch, adjusted the wires and it ran for 3 days and I shipped it off to the customer.

He had it about a week and said it stopped. I got it back, and it was obvious that the index pin (jewel) was missing the the index wheel.

First thought, bad index jewel.

I checked it out,got it running and it seemed fine.

Stopped again, with the balance wheel still in motion, but the wheels stopped due to the index wheel not moving and no impact from the index pin or jewel.

This indicates that there is a problem with the magnet that is set in the pillar plate to advance the index wheel. Literally the magnetic attraction on the steel wheel pulls it forward and lines it up over the magnet, after the index pin hits it. This action moves the wheel train forward. Of course, it also should prevent it from going too far forward too.

This first picture points out the magnet I am talking about:

www.pawatchmaker.com

Now I knew the magnet worked, but it was weak. the only way to correct the problem is to replace the magnet, or move the magnet closer to the index wheel, and hope the magnetic energy will advance and line up the index wheel properly.

The tools used for this arethe staking set, using a hollow faced stump or punch and a flat faced punch. A jeweling tool could also be used.

Then you just move the magnet up throught the pillar plate.

In this photo, if you look carefully, you can see the little magnet under the wheel, in closer proximity to the index wheel.
In order to test it, the watch needs to be completely assembled with the contact and trip wires adjusted.
I had to go through this process three times until I had the magnet close enough to always get one of the teeth of the index to stop directly on top of the magnet. It is now actually closer than Hamilton wanted it, and just barely clears the wheel.

Below is the photo of the running watch, prior to getting shipped out.