Bent Tooth. Do I Call An Orthodontist?

[swordfish]

I first began working on the repair of this Elgin (grade 488, size 18/0, manufactured around 1935) over a year ago.  I was stymied.  I just couldn't get it working.  So I set it aside for a while.  Now, my skills in watchmaking have improved somewhat, so I decided to look into it again.

 

I did a series of diagnostic steps, such as I would not have considered a year ago.  When I removed the balance wheel, the watch still would not run (even as I gently moved the pallet back and forth).  When I removed the pallet, it STILL would not advance.  I thought at first that the escape wheel pivots were not placed properly in their holes.  I carefully replaced the escape wheel, assuring its proper placement.  STILL it wouldn't run.  But I found that when I gently moved the fourth wheel, the escape wheel would turn UP TO A POINT.  Then it was stuck.  I suspected a bent tooth on either the fourth wheel or the escape wheel pinion.

 

AHA!  There it was!  I found a bent tooth on the fourth wheel.  Whenever it engaged the escape wheel pinion, the watch stopped!

 

You can see the bent tooth in the attach photos.  The bent tooth is opposite where one of the armatures of the wheel meet the circle of the wheel.  (There's probably technical language for that, but I don't know it.  Also, I don't know how to rotate an image here so that the orientation of them is the same.  Sorry.)    

 

So, now I feel very clever for having diagnosed the problem.  But, of course, making a diagnosis is just the first step.  Now I have to cure the problem. (I am a physician by vocation, and watchmaker by avocation, so I well understand that (1) not every diagnosis is a COMPLETE diagnosis, and (2) not every diagnosis leads to cure.)  I have never straightened a bent tooth.  I imagine that attempting to do so risks breaking it off entirely.  

 

I invite advice from my friends in this forum.

 

 

[cdjswiss]

It appears that other nearby teeth are bent? My solution would be a replacement fourth wheel.

http://www.dashto.org/newlists/selectedamericanmaterial.htm

list a size 18s Elgin fourth wheel item 25.2012 that might fit

[WillFly]

I'd agree with that - there are a number of suppliers in the US who stock Elgin pocket watch parts so, with a bit of luck and perseverance, you  should be able to obtain a fourth wheel.

 

Cheers,

 

Will

[rogart63]

A dental technichan would be better? He could do an implant for you ?  

Edited September 13, 2015 by rogart63

[bobm12]

Hi guys,

 

Check this out, pg. 26!

 

Cheers,

 

Bob

 

September2011.pdf

[swordfish]

Using a replacement wheel was good advice. I had one left over from a year ago when I last attempted to repair this watch. When I swapped in that wheel, the gear train ran smoothly.

BUT...when I then replaced the pallet, the watch would not run (as I gently wagged the pallet as the roller jewel would). I could not see a definite defect on the pallet stones, but when I replaced that pallet, the watch worked. In a few days I'll be able to post a photo of the presumably bad pallet to get your assessment. I notice that there is more shellac at the base of the exit stone than the entrance one. I wonder if that pushed the jewel too deep into the escape wheel.

So now the remaining task is to replace the balance. I see that the impulse jewel is missing from its roller table. <sigh>. (Remember what I said about COMPLETE diagnoses?). I have a replacement roller table with jewel. I've never done this before, but I've read about it. I'm going to carefully use my staking tool to remove the old one (without the impulse jewel) and then replace it.

I do have a question, however. It seems that the balance wheel and arbor should not have the hairspring attached during this process. To remove the collet, it seems safer to first remove the stud from the balance wheel cock. I'm hesitant to introduce more opportunities for error, but this seems necessary. Am I right in this regard?

I'm eager to repair this watch because it was my late (and dearly loved) father-in-law's, and it will become an heirloom for one of my sons.

Bob12, the link you posted is impressive, but beyond my current tools, and more importantly, beyond my current skill.

Sent from my iPad using Tapatalk

[agoldflam]

Oh how exciting your story. I hope you get it running! I think I'm following along so far. First and foremost it is possible to introduce more errors once u need to install a new roller but at this point it appears u have no choice. You could install just the roller jewel and shellac it in but generally if u have the whole roller then I would just replace it completely but u may need to be a little familiar with the hairspring upon reassembly.

You have to remove the balance complete from the balance cock and the lift off the collet/hairspring.

Line up where the roller jewel is on the balance wheel and mark it before taking it off. I prefer to use 2 razor blades to remove a roller and a light tap from tweezers usually pops it off.

Next install the new roller so the jewel lines up where you marked. After you go through the reassembly note how the hairspring is once u install the stud back in the balance cock as sometimes the flat or centering may be off a little.

Hope this helps and isn't to confusing.

Through watchmaking I restore connections in people's lives!

[swordfish]

Thanks, agoldflam. I have the plan clear in my head. I hope my fingers will be able to accomplish it. I'm deferring doing it until I have a few anticipated uninterrupted hours.

Here is a photo of the pallet which I removed because it wasn't working. I don't know why. I do see more shellac at the bar of the exit stone than the entrance stone, but I don't know if that's enough to stop a watch.

Sent from my iPhone using Tapatalk

[bobm12]

Looks like you are going the right direction, swordfish, keep us posted!

 

Cheers,

 

Bob