I know that after I danced Gangnem Style in the last video you thought this was going to be the “Harlem Shake” but it isn’t.
Endshake is the amount of play that an arbor has along its axis between the two bearing surfaces. On the 3130 Rolex specifies an endshake of 0.01mm to 0.03mm for the barrel arbor between the two bearing surfaces (one in the mainplate and the other in the barrel bridge.) A watchmaker needs to be able to judge this play without any measuring tools. He usually does this as much by feel as he does by visual confirmation. It has been quite some time since I had any feedback on my endshake adjustments so I set up a vertical micrometer dial gauge and measured the endshake of this barrel arbor without making any adjustments. Now its your turn. Below is a video of me testing the endshake of the barrel arbor in a Rolex 3130. How much endshake do you think this barrel arbor has? Leave your guess in the comments.
Adjustments to endshake in modern watches are made using a jeweling tool, like the Horia, Seitz, or Favorite.