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Subtleties in pulling out a Speedmaster crown...

  1. M'Bob

    M'Bob Aug 1, 2020

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    I’m curious what most of you lads do, even though you may not have analyzed it: do you just grab and pull out; or do you pull while squeezing the middle and thumb nails inward, along the bevel, in a combined motion?
     
    Edited Aug 1, 2020
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  2. Evitzee

    Evitzee Aug 1, 2020

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    Slip my right hand middle finger nail under the crown on the bottom side and use it to pull the crown out. Don't use my thumbnail.
     
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  3. mr_yossarian

    mr_yossarian Aug 1, 2020

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    All said.
     
  4. M'Bob

    M'Bob Aug 1, 2020

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    So, if I’m getting you correctly, just one finger, no counter-force with another?
     
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  5. Evitzee

    Evitzee Aug 1, 2020

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    Correct...I'll support the top of the crown with my thumb but all the pulling is done by the middle nail.
     
  6. M'Bob

    M'Bob Aug 1, 2020

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    Interesting. Now I’ll have to go check to see if I pull with the thumb, or just support it as you say.
     
  7. shishy

    shishy Aug 1, 2020

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    This is how I do it now for a lot of my watches. In the past I used to use both fingers, which in practice meant I applied all the force I could from my forearm and, well... pulled out a couple crowns just completely out. Never again.
     
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  8. KingCrouchy

    KingCrouchy Aug 1, 2020

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    I just use this handy tool to pull it out and don't hurt my fingers.:thumbsup:
     
    Zwickzange-Kneifzange-53986_bdefops-L.jpg
  9. Mmike1357

    Mmike1357 Aug 1, 2020

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    Definitely use the middle nail, except I clipped it too short today, better not let this baby stop until it grows back! C7451D6D-8DAF-498F-A159-9CB65F45A8ED.jpeg 29A58C55-9F19-46D0-921E-7B4E51124C71.jpeg
     
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  10. M'Bob

    M'Bob Aug 1, 2020

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    Thanks for the picture, So, you basically just pull it out with middle finger as noted, with no help from the thumb?
     
  11. Mmike1357

    Mmike1357 Aug 2, 2020 6:21am

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    I sometimes steady the opposite side with the thumb, but not always
     
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  12. M'Bob

    M'Bob Aug 2, 2020 6:58am

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    Here’s what I’ve found after playing with this, with many watches, over the last day. Now, someone could rightfully ask, why is this relevant? The answer is, one would assume that you want to exert the leases force possible to accomplish the job. I don’t know the innards of a watch well enough, but something keeps the crown from getting fully pulled out, and i would think that snapping into that set position with as little force as possible would be a good thing.

    Anyway: regarding simple, manual wind dress watches, it seems that the crown is often thin, and takes very little force to just pull it out to the set position.

    With something like the Speedmaster, the crown is relatively thick, and also requires more force to get into that set position. So it appears that if you try and pull it straight out, there is more force used than necessary, versus just wedging one or two fingers in, which makes the velocity the crown pops out at much slower.

    Still interested in some of the techniques of others.
     
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  13. Donn Chambers

    Donn Chambers Aug 2, 2020 8:00am

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    It’s always interesting to see what other people muse about that I had never event considered! :)

    Anyway, when I looked at what I do, I slip a nail under the crown (caseback side) and pull it out. I don’t touch the top (dial side) at all, never even considered “balancing” the torque, because it’s so small if you pull straight out that I can’t imagine it’s a problem.

    Been doing this for decades with every watch I’ve owned and never had a problem.
     
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  14. Archer

    Archer Omega Qualified Watchmaker Aug 2, 2020 9:11am

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    This might help - took this photo for you to illustrate how the stem is retained in the watch:

    Stem retention.jpg

    The part laying on the bench is called the setting lever. It has a small post on it that fits into a slot in the stem that you can see. This is what keeps the stem from pulling completely out. This is a macro photo, and these parts are from an ETA 6497, so a large wrist watch or medium pocket watch movement. So these are quite large in comparison to what you would find inside something like a Speedmaster, or a smaller movement. The post is 0.78 mm in diameter to give you an idea of the actual size.

    If either the post or slot in the stem is damaged, the stem can pull out of the watch more easily. In many vintage watches the post can get damaged by someone inserting the stem back into the movement, and screwing down the setting lever screw without first making sure the post is in the slot. Also, for those who like to keep original crowns that no longer seal, if you happen to get the watch wet when moisture enters this area it often leads to this:

    Rust damage1.jpg

    In the above photo the post is facing down to the stem so you can't see it. Here is what the other side looks like:

    Rust damage 2.jpg

    Not all stems look like the one I show above, and some the portion of the stem that resists the stem pulling out is very thin. In the above example there is a long section of full diameter stem just to the left of the post, so you can't really break this off. In this example, the stem only has a thin ring of material:

    Stem retention2.jpg

    I have come across watches where the ring has snapped off in one spot, so if the stem is rotated to that position, it will slide right out. So being careful with the crown is a good idea, but if the watch is kept in good condition this usually isn't a problem.

    The crown itself doesn't have a whole lot to do with the actual force required to pull the stem out, as this is more a function of the setting mechanism inside the movement. The geometry of the setting parts and how they move (the leverage available) the strength of the yoke spring and of the setting lever jumper, and state of the lubrication in this area will all have more impact on the forces required that the crown will.

    This is a Panerai I worked on this year, in the process of being disassembled. The movement is the same ETA 6497 in my first photo above:

    Setting.jpg

    When the crown is pulled out at 1, the post on the setting lever that keeps the stem in the movement is pivoted, and it moves at 2. This moves the yoke at 3, which has to compress the yoke spring - the U-shaped spring, which is quite a heavy spring in this watch. In watches with a lighter spring, this will not require as much force.

    Ideally you would not really want to pull on the crown with a lot of force, and I would suggest that if pulling the crown out requires enough force that you are concerned about it pulling the stem right out of the watch, the setting area may need some lubrication or other attention.

    Hope this helps.

    Cheers, Al
     
  15. Dan S

    Dan S Aug 2, 2020 9:19am

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    So would that be considered damage, or patina. ;)
     
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  16. Archer

    Archer Omega Qualified Watchmaker Aug 2, 2020 9:22am

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    I call it "parts needed"...

    I managed to save the rusty sliding pinion, but the winding pinion was too far gone. It's a discontinued part on a Cal. 321 (which this is) and going to the well of the open market is not an inexpensive experience. The setting lever is still stocked for the 321, so although it was replaced it wasn't expensive (at least relative to the winding pinion).
     
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  17. M'Bob

    M'Bob Aug 2, 2020 10:08am

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    Al, this is really excellent, many thanks.

    A question: in the photo below, the setting lever has that little nub on it that sits in the stem. Would this, then, be the position it’s in when the crown it flush against the case, or pulled out, in the time-setting position?

    7DD5565E-AF80-416E-9055-369EF72EBAF6.jpeg
     
  18. Archer

    Archer Omega Qualified Watchmaker Aug 2, 2020 10:13am

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    Neither - it's just that way to help support the stem for the photo.
     
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  19. M'Bob

    M'Bob Aug 2, 2020 10:23am

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    Thanks. Let me marinate on your pictures a while and see if I can get more of a clear idea of where the various stem portions abut the setting lever in the wind vs set positions.
     
  20. Archer

    Archer Omega Qualified Watchmaker Aug 2, 2020 10:30am

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    The only thing that contacts the stem on the setting lever, is the post...