Jump to content

Measuring pivots

gary17

By gary17
in Watch Repairs Help & Advice

 Share

Recommended Posts

gary17 Super WRT Addict

gary17

Posted
Posted

Hey

When you are measuring the thickness of a shaft pivot what part of the pivot is correct for jewel hole? 

Thickest part of the pivot? The tip? Or the middle? 

Cheers

Gary

watchweasol Distinguished Member

watchweasol

Posted
Posted

Hi Gary  Middle to tip  that should be parallel, It rather depends on whether the shoulders of the  staff/pinion you are measuring conical or square shouldered.  the bit you are measuring is the working surface of the pinon.

  • Like 1
nickelsilver Distinguished Member

nickelsilver

Posted
Posted

For pivots under 0.15mm-ish, especially balance pivots, you really don't want to use a micrometer. Even with a very soft touch you are almost sure to make a microscopic (or not so microscopic) pair of flat spots. For these it really is really important to use a jewel gage, which is a plate with jewel holes in increments from 0.07mm up to 0.25 or so, by 0.01 or 0.005 or 0.0025mm increments depending on the tool. Some will go down to 0.06mm (you really really don't want a mic on those little guys).

 

 

  • Like 1
nickelsilver Distinguished Member

nickelsilver

Posted
Posted
7 minutes ago, gary17 said:

I was gonna use a jka feintaster. 

That should be ok. Just be careful not to tilt anything when the jaws are in contact, they can still leave marks.

 Share
Go to topic listing

  • Recently Browsing

    • No registered users viewing this page.

  • Topics

  • Posts

    • zx6rfool
      Hi From Virginia

      By zx6rfool · Posted

      Decided to update with the repaired watch back in rotation and the new anniversary gift.   
    • BobG
      Etachron regulation system

      By BobG · Posted

      I’ve been playing with a NH35 movement that which has the classic Etachron regulation system and a few balance assemblies as practice. What I’m trying to do is get comfortable with the effect both the stud and regulator pin positions have on rate and positional error. When I install a new balance assembly I install it with the assembly in place  on the cock and cock is attached to base plate. I use the back of the tweezers to push the stud into place and feel the click. However, I noticed that the angle of the stud can be adjusted and what I also noticed is that some movements have the stud carrier arm bent down a little and that changes the angle of the hairspring leaving the stud. This angle effects how the spring goes through the regulator pins and also the spacing of the coils opposite the stud. What I thought I was supposed to do is set the regulator block in the middle of the curve, open the pins, and use the stud angle to center the spring.  Then the stud is set.  Now on all the new NH movements I have seen the angle of the regulator block is about 60 degrees counter clockwise from full open. I watched a video where the author used the regulator pin adjust to adjust rate and position error. When I close down the pins I do notice that the rate increases but also the amplitude drops, the coil spacing changes and hairspring appears slight straighter between the stud and the regulator block. If I open the pins the amplitude comes back, the spring breathes a bit more between the stud and the regulator block and the rate slows.  So, a long post I know but I would really appreciate any advice on how to correctly adjust the etachron system for rate, amplitude and positional error.   
    • Neverenoughwatches
      New forum member, new learner

      By Neverenoughwatches · Posted

      Aw come on Andy, it was just a comparison between spending 30 quid and tackling a tricky piece of work. You appeared to be volunteering,  i volunteer for stuff all the time it gets me into all kinds of trouble.
    • Neverenoughwatches
      Tissot case back removal

      By Neverenoughwatches · Posted

      It's not really shown here , but the blade flips over, so it faces the other way. The knob and threaded case holder then pushes the caseback seam into the blade. Once the blade starts to penetrate into it, the lever and blade are lifted , which should hopefully pop the back off. A lot of fashion style cases have very tight seams and need a sharp blade to start separating them.  Don't buy the cheaper plastic versions of this tool, the posts with the pins through for blade holder break easily if the apply extra force to blade. 
    • tomh207
      New forum member, new learner

      By tomh207 · Posted

      You will still be looking for a balance complete I’m afraid, this is the balance staff, balance wheel and hairspring in one package. Hairspring and the balance wheel are matched in the factory. Whilst we can change a balance staff the hairspring and balance wheel stay together.   Tom
×
×
  • Create New...