Jump to content

Joining broken mainspring

dnhb

By dnhb
in All Things Clocks

 Share

Recommended Posts

dnhb Watch Enthusiast

dnhb

Posted
Posted

I want to rejoin two halves of a broken mainspring in order to be able to run a clock movement I'm cleaning - and which may require repairs to its components - to see if it will be worth purchasing a new mainspring. So it doesn't need to last longer than it's going to take to diagnose - & hopefully fix - any problems. I can think of 2 approaches: a) riveting the two pieces; & b) cutting a slot in one piece and a 'T' at the end of the other. I'd be grateful for any suggestions/comments. Doing such a repair will also be useful experience for future repairs to the ends of mainsprings which seem to be a common requirement to master.

Link to comment
Share on other sites
rjenkinsgb Watch Enthusiast

rjenkinsgb

Posted
Posted

If the break is near one end, could you heat it at the broken end and let it cool slowly, to remove the tempering, then drill & file a slot to re-attach it?

It would not run as long as with a full length spring - but if it's just for diagnosis it should not matter?

 

Link to comment
Share on other sites
dnhb Watch Enthusiast

dnhb

Posted
  • Author
Posted
16 minutes ago, rjenkinsgb said:

If the break is near one end, could you heat it at the broken end and let it cool slowly, to remove the tempering, then drill & file a slot to re-attach it?

It would not run as long as with a full length spring - but if it's just for diagnosis it should not matter?

 

Yes: I've done that on a pocket watch spring recently - to my surprise ! Unfortunately, RJ,  the break is right in the middle of the spring and in any case I'm just interested to see what the options are & how I get along trying exercise them....

Link to comment
Share on other sites
Nucejoe Distinguished Member

Nucejoe

Posted
Posted (edited)
11 minutes ago, dnhb said:

 the break is right in the middle of the spring 

If there is an eye into which the barrel arbour hook locks. 

Heat the other end ( broken end)  to a glow, then shaping a spindle is easy, I done bend them with a pair of cheap tweezers.  

Good luck

Edited by Nucejoe
Link to comment
Share on other sites
dnhb Watch Enthusiast

dnhb

Posted
  • Author
Posted
1 minute ago, Nucejoe said:

How long is each piece?

Which end of the longer piece is broken?

 

I appreciate where you're coming from, N, but I'd like to try to reconnect them all the same.....

Link to comment
Share on other sites
dnhb Watch Enthusiast

dnhb

Posted
  • Author
Posted

I've gone with a 'T' & 'tear drop' slot approach as this provided some filing practice. My question now is: do I reheat each piece (to Straw or Red ?) & quench or just leave the material as is following the initial annealing to make it workable? (I did woodwork not metalwork at School!).

Link to comment
Share on other sites
nevenbekriev WRT Addict

nevenbekriev

Posted
Posted

Leave the ends soft. Two reasons: 1. The harder they are, the easier to break again. 2. No mater how perfect You have hardened the end, next to the hardened place always lefts annealed soft part between the end and the rest of the spring. So it is not possible to achieve uniform hardness unles You harden the whole spring, which is not easy thing to do.

Then, hardening a steel needs knowlage about the steel and what is the correct regime for hardening. It is easy to damage a steel by overheating or burning the carbon in it for example.

  • Thanks 1
Link to comment
Share on other sites
nevenbekriev WRT Addict

nevenbekriev

Posted
Posted

I agree, such spring doesn't behave as normal spring.  But, You can try it. It mainly depends on the type of clock and what torque is needed to keep it working. The isochronism is the thing thart will suffer the most.

  • Like 1
  • Thanks 1
Link to comment
Share on other sites
dnhb Watch Enthusiast

dnhb

Posted
  • Author
Posted
17 hours ago, oldhippy said:

Joining in the middle I don't recommend it. Don't you have a complete m/s you can just try it doesn't have to be the correct one. 

No: I haven't built up a store of bits & pieces yet, OH, having only begun my journey last year as I would down my consultancy business. If I can get the clock working then I'll get a new M/S. (BTW I'm still hoping to hear from you as to what you mean by "platform" in your comment on my "Charity Shop purchase" thread in which you did helpfully tell me that the clock was of the French 8-day variety).

Link to comment
Share on other sites
nevenbekriev WRT Addict

nevenbekriev

Posted
Posted
On 4/9/2024 at 1:41 PM, dnhb said:

No: I haven't built up a store of bits & pieces yet, OH, having only begun my journey last year as I would down my consultancy business. If I can get the clock working then I'll get a new M/S. (BTW I'm still hoping to hear from you as to what you mean by "platform" in your comment on my "Charity Shop purchase" thread in which you did helpfully tell me that the clock was of the French 8-day variety).

Platform is the small separate plate with the escapement and balance on it.

  • Thanks 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.

×
 Share
Go to topic listing


  • Recently Browsing

    • No registered users viewing this page.

  • Topics

  • Posts

    • quantieme
      Rolex 2236 winding in a mainspring Flared end no hole

      By quantieme · Posted

      Hi All, just gone to wind in the mainspring on this Rolex  cal 2236 to find that it does not have a hole but instead is flared on the end to sit in the flared part of the arbor. Does anyone know if there is a winder on the market for this as although I have not tried yet I am assuming that my standard winder will not work in this case. thanks. Any help or advice appreciated.
    • ManSkirtBrew
      Omega 1001 lubrication questions

      By ManSkirtBrew · Posted

      A friend brought me this beautiful Omega to service. It's the first time I've seen this movement, so I'm looking through the technical guide for...guidance. Sorry for the photos instead of text--I wasn't able to get a satisfactory cut-n-paste. The PDF is attached. First question: are they suggesting *all* of these parts be treated with epilame, or just saying they are treated from the factory with a special coating?   Most everything else I can work out:   But my second question is this guy, from the automatic winding block. I'm assuming it's a one-way clutch, and I did not want to risk taking it apart with no knowledge of it. So do I take it apart? How is it lubricated? I have Lubeta V105, would that be appropriate here? Omega 1001.pdf
    • Neverenoughwatches
      Breguet hairspring frequency

      By Neverenoughwatches · Posted

      Its nice to be shown appreciation for any advice thats been given. Thanks Murks.
    • Terrinecold
      First movement = First broken movement

      By Terrinecold · Posted

      Thank you for the advice.  Actually I have already ordered a replacement one as soon as I broke the setting lever screw.  It is supposed to arrive today or tomorrow, I got it from AliExpress for $27.51. In the meantime this Sunday I got from amazon the cheapest mechanical watch I could find (a pocket watch with a 2650G movement).  That movement is now sitting disassembled and waiting for reassembly.  I have to say I found that movement pretty ugly compared to the ST36.  The fact that it is skeletonized and center second made it interesting but all the bridges feel very bad quality. One thing which happened with this one (due to the skeleton nature) is that I had trouble removing the hands with my presto tool (I have levers on order but not arrived yet).  I bent a bit the little retainer (the part at the bottom of the picture).  Then later on I couldn't find the cannon pinion.  I finally found it it was in the hour wheel.  I must have pulled it out a bit initially and then oil kept it in there. The other thing which happened is that when I tried to open the case back which the back crystal (plastic, glued) came out.       Anyway tonight is reassembly time for this one. I also have an NH35 and a Mingzu 2813 on order. One question:  I was thinking about getting some old soviet movements which I see on ebay for pretty cheap.  All that to keep practicing and hopefully learn not to break anything before I start trying to service a real watch.
    • eccentric59
      First movement = First broken movement

      By eccentric59 · Posted

      The ST36 isn't an expensive movement, so it might be easier to just get a replacement for parts. Here's a listing in the U.S. for $33 + $3 shipping. Once you get current movement running you can tackle the tangles hairspring without the pressure of making it worse.   https://www.ebay.com/itm/353824212893?itmmeta=01HYDN4TGZSXFCW4TXZ2THH0C1&hash=item526191079d:g:sT4AAOSwHidhcQO6&itmprp=enc%3AAQAJAAAA8Jw5K76smZgFGzM5ubLY769v%2B6EbBphCYo99M48gxLxxMjir9tRyn32O8Q5AgmKh1aKUP%2FfaCOIz8a7YMGkflhGWus7BDQIzrs45yo8NCZ66Jmti1Qli2%2BjaAm%2F8Ogg81F17LdC5Ulu54cnXSOCtaMkQcp03pcluBqTAuZPxbYwkrOC38sb%2FtlDewlZBOhjtA7pZTTMAql7hFKbrkc5RyF%2BtGL2%2Br9BS7mzgd%2BxdDF08HcVn6rvOawDjEbMPs9mYSegv6DVnSoiYYpMGzPJE7Qyd782Brjl05GQTL9MzpFuWrQvUTNxyY5%2BNQi18XTmf4A%3D%3D|tkp%3ABk9SR8yok7XzYw
×
×
  • Create New...