Jump to content

Vibrating a hairspring - would this even work?


Recommended Posts

I’m interested in all the tools and techniques involved in this venture, but as a hobbyist I don’t think a full Luthy tool is in my future. I did find a lower-tech tool made by Swartchild that allows you to suspend the balance and hairspring on a transparent plate, under which you can place a watch that has the correct BPH so that its balance is visible and you can use that as a reference. I realized that I could just as easily suspend the hairspring on an iPhone screen, if I could find a video or a simulation to run as a reference. On the amazing web page by Bartosz Ciechanowski dedicated to the engineering and physics of the mechanical watch, there is a balance oscillation simulation that worked well. Here's a link:

https://ciechanow.ski/mechanical-watch/

I grabbed an unknown spare balance out of the parts box, suspended it from a pinch point a bit away from the pre-placed stud, and by adjusting the parameters of the simulation it turned out to have a periodicity of close to 0.4 seconds, which would make it an 18,000 BPH balance. I then adjusted the pinch point until the balance was matched to that specific rate in the simulation (see video). The rate of oscillation in the simulation can be changed to provide other BPH rates, so it could be useful if this would work.

My question is regarding the level of absolute precision required to place the stud, because the timing of a web-based simulation like this may not be exactly on the nose. The placement is certainly important to allow a full range of regulation, but knowing that the regulator will be used for the ultimate fine tuning, is a setup like this likely to be accurate enough to set a new hairspring into the functional zone?

Video of this setup:

https://www.youtube.com/shorts/WH58LR0AL_4

  • Like 1
Link to comment
Share on other sites

You can certainly do it like that! You can even do it with a stopwatch just counting the beats of a suspended (but supported on lower pivot) balance, I've used that technique for odd beats like 20,222 or 19,444. Though in my case I have a Luthy tool, which makes it handy to set the balance in motion and adjust the length of the spring. With a flat hairspring you would generally stud it with a bit of extra stickout in case you need to let some out when it's in the actual watch. With an overcoil you really have to get it bang-on when vibrating as lengthening or shortening might mean the overcoil gets thrown off.

 

In any case you want your balance to stay synced with the reference balance (or video) for a good minute or you will be playing around a lot in the watch.

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • Hi I got a Jaeger LeCoultre K911 movement, where one of the stems was broken. Part no. Should be 401.  Im based in Europe and tried Cousins but its discontinued there and cant find it on Google. Is there a way out to join the ends? Or an alternative movement to source parts from? 
    • The part was how it fell out of the movement - the train wheel bridge wasn’t screwed in.    I’ll probably dismantle the part, if I can, to work it out.    The train of wheels ran fine - it was only once the keyless works were installed I noticed the problem. 
    • Hello, I am about 5 months into watchmaking and I love it!   The attention to precise detail is what really attracts me to it. (and the tools!) I am working on a 16 jewel 43mm pocket watch movement.   There are no markings besides a serial number (122248) .  The balance staff needs replacement. The roller side pivot broke off.  I successfully removed the hairspring using Bergeon 5430's.  I successfully removed the roller using Bergeon 2810.   Did i mention I love the tools?! I removed the staff from the balance wheel using a vintage K&D staff removal tool  with my Bergeon 15285 (that's the one that comes with a micrometer adjustment so it can be used as a jewel press as well as a traditional staking tool...it's sooooo cool...sorry..  can you tell i love the tools?) No more digressing..  I measured the damaged staff in all the relevant areas but I have to estimate on some because one of the pivots is missing. A = Full length  A= 4.80mm  (that's without the one pivot...if you assume that the missing pivot is the same length as the other pivot (I'm sure it's not)  then A = 5.12 mm...(can I assume 5.00mm here?) F=  Hair spring collet seat  F=  .89mm   (safe to assume .90 here? .. I am sure that my measurement's would at least contain  .01 mm error ?) G = balance wheel seat  G = 1.23 mm  (1.20mm?) H  =  roller staff  H =  .59mm  (.60 mm?) B  = bottom of the wheel to roller pivot   B  = 2.97mm  (3.00 mm?)     here I am estimating  again because this pivot is missing. So my friends, and I thank you profusely,  can you point me in the right direction as to how to proceed? Do i buy individual staffs?  or an assortment?   Since I don't know exactly the name of the manufacturer, will that be a fatal hindrance?   Tbh, I'm not even sure what country of origin this movement is. Thank you!    
    • Thats why i asked that question earlier, what happens if lubrication is placed directly on top of epilame ?  As opposed to walled within its non epilamed area . I'm not saying its right, i have no idea , just asking questions. 
    • thinking of where epilam should be removed did you know there was a patent that covers this? At least for the escapement I'm attaching it. GB1057607A-1 epilame.pdf
×
×
  • Create New...