Jump to content

Recommended Posts

Posted

Hi All,

I'm just learning the very basics at this point.  I've picked up an Elgin grade 345, 12s PW on ebay.   Here's more info: https://pocketwatchdatabase.com/search/result/elgin/20602697/movement

It runs for maybe a minute at most before stopping.  I'm attempting to disassmble and clean it as it's terribly dirty.  

I didn't get far.  At the moment, I'm not able to remove the stuborn screw on the ratchet wheel.  My question is whether it's lossened clock or counter clockwise?  I've read that ratched wheel screws can go either way.  Also, is there some type of screw treatment (oil, etc) that would help?

Many thanks

Charlie

 

 

 

 

 

IMG_0282.JPG

Posted

before you apply too much torque;    keep asking till you get and answer on the screw direction.  if you have already tryed, its sprobably too tight or rusted.  use penitrating oil and heat before you try again.  vin

  • Like 1
Posted

I hope you have a good set of screwdrivers that were sharpened and prepared accordingly. (google it as there are guides for that as well)

I've had success by pushing down on the screwdriver with a bit of force but be careful not to slip the screwdriver tip and scratch or even damage something. (only attempt as a last resort, perhaps)

Those screws can indeed go both ways...

Posted

Ratchet wheel or crown wheel? Ratchet wheels on American Pocket watch is a standard screws it's the crown wheel that's usually left-handed.

Posted

Fletcher's book "Watch repair as a hobby" has this:  "Now remove the ratchet wheel by unscrewing the screw at its centre; this is either right-or left-handed according to the whim of the maker."

Neither the screw at the 6 o'clock position (crown wheel?), nor the screw on the wheel to its left (winding/ratchet wheel?) will budge.  Not sure of the direction of either.

Charlie 

Posted

If you look at the picture you attached, the crown wheel will rotate counter-clockwise when the stem is turned to wind the mainspring. It will, in turn, cause the ratchet wheel to turn clockwise. In this particular case, the crown wheel screw should be a left hand thread and the ratchet wheel screw should be right hand thread, If the crown wheel screw were right hand thread, the winding motion would tend to loosen the screw. Same rule applies for the ratchet wheel screw.

All bets are off when it comes to Swiss watches. I've seen it go either way at the whim of the designer. If I'm not sure, I put a little pressure on the screwdriver in either direction to see if I can detect the screw starting to loosen. With a little luck you can usually get the screw out in the correct direction without shearing off the screw head.

Posted

Watchfixr,

Thanks very much.  I'm still waiting for the larger screwdrivers I've ordered to arrive.  I'll let you know how it works out.

 



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • I see. And is there a possibility to convert it to a springless system by replacing it with a standard split stem model?
    • Sharpening gauge.   I found the easiest side to do was the safety roller as the roller table laid flat on a block provided stability.  The other way requires a specific stump for the roller and pin to sit in, but may also grip better way.
    • Yes, the problem isn't so much with the 'background' radiation but inhaling or digesting loose flakes and dust that can become airborne.
    • The spring is so the crown pops out to the winding position when unscrewed.
    • Radium and the horrible story of the Radium Girls scares everyone - But there is also a lot of paranoia here.  I did a whole bunch of readings on a watch with Radium lume recently. My Geiger counter read 2µsv/h through the crystal with the sensor part of the Geiger counter right on top of the watch.  This measurement dropped off to the normal background rate of 0.18µsv/h as soon at the Geiger counter is just a few cms away. Measuring from the back of the watch and there is virtually no increase.  The rate went up to 5µsv/h from the dial and hands when the movement was removed from the case. To put this in perspective a Frankfurt to New York flight would give you about 50µsv of exposure and a chest x-ray about 100µsv.  Norwegian labour law states “The limit value for workers over the age of 18 years is set to 20 mSv per calendar year.” - that is the equivalent of 400 flights across the Atlantic! I will however point out at this point it is important that you don’t ingest the radium from the watch! One of the worst things you can do is scrape the radium off the dials and create radioactive dust that you could breath in! That being said… If for each radium lumed watch you work on you spend 15 minutes getting the movement out of the case and the dial and hands off and then another 15 minutes at the end putting the dial and hands back on your exposure would be less than 2.5µsv  Once you have the hands and dial off they can go in a box and put safely out of the way (probably good practice for any watch!). I believe the risks are negligible If you take precautions such as wearing a mask and gloves and wiping your work surfaces down with a damp paper towel and disposing of the towel, gloves and mask once you are finished  
×
×
  • Create New...