Internet Horology Club 185
What's this little screw for?

This topic can be found at:
https://ihc185.infopop.cc/eve/forums/a/tpc/f/3426047761/m/2446020933

June 05, 2003, 07:58
John D. Duvall
What's this little screw for?
A fellow member recently emailed me about a little screw on an Elgin 12s that for all practical purposes had no purpose. Normally, when you see a screw in one of the movement plates, it must be holding something together, right? Well, many Elgin 12s grades utilize what is called a "Setting Cam Stop Screw". It doesn't hold anything together but it does serve a useful function.

Before we get into the mechanics of this little screw, first imagine that we have just cleaned and oiled our newly acquired 'Elgin 12s, 7J Practice Movement'. Before it is installed into the case, we want to wind it and check for accuracy. To our dismay, it runs very slow and may even come to a grinding halt. What happened?

Well, when the movement is removed from the case, it is in the 'setting' position (typical stem wind, stem set). In this position, for the watch to run, it must not only move the hands but also drag all of the setting mechanism with it! This includes the clutch and winding arbor. We must find a way to return the watch to the winding position without reinstalling it into the case.

Our little screw comes to the rescue!

To get the movement into the 'winding position', we simply push our bench winder into winding arbor hole, placing the movement into the winding position and tighten our little screw down into the detent of the setting cam. This will now hold the setting mechanism in the winding position so that we can time and adjust our watch out of the case.

Before reinstallation of the movement, simply back the little screw out flush with its surrounding plate. Don’t try to remove it this way though! To remove this screw, you have to remove the barrel bridge plate and turn the screw clockwise until it exits out the bottom of the plate.



I plan on doing a series of these little “Helping Hand” tutorials. Please feel free to email me with any comments you might have, good or bad! I was a Technical Instructor in the USAF so trust me, you won’t hurt my feelings.

John D. Duvall
NAWCC Member 0144772
NAWCC IHC Happy Camper 192
Chapter 185 Watch Repair Moderator


June 05, 2003, 08:36
Terry Hill
Cool Cool

Look forward to the next installment
June 05, 2003, 15:40
Steve Maddox
I second Terry's opinion!

I think these "tutorials" of yours are great, and it's really rewarding to see someone like you put forth so much effort to help fellow enthusiasts!

Keep up the good work, and feel free to call on me any time if I can be of assistance!
June 05, 2003, 17:29
Jim Cope
...this is/for another reason why I'm glad to belong to this Chapter!!!...thanks! John...Jim C
June 05, 2003, 21:29
Frank Juchniewicz
Thanks John
Keep them coming, I learn something every time I visit this chapter.

Frank Juchniewicz