Jump to content
  • 0
Chopin

Does this hairspring look good to you?

Question

16 answers to this question

Recommended Posts

  • 0

Hi From the pictures it looks ok, The kink in the spring is deliberate to allow the outer coil to work between the regulator springs. As long as the balance when fitted to the watch has the spring lying flat and when observed from above the coils of the spring beat evenly and have no sticky action all will be well, If you see the spring jerk during operation its probably oiled up causing the coils to stick.

Share this post


Link to post
Share on other sites
  • 0

Looks OK, pinions also look complete,  but as Watchweason says, probably needs cleaning (or possibly, but less likely, de-magnetizing).

Does the watch run free without the balance fork?

Does the balance fork click over nicely when fitted?

Is everything clean?

Given that it is a plastic movement, how did you clean it?

How did you lubricate it (if at all)?

Is the shock arrangement surgically clean?

I haven't looked at any of the Tissot plastic movements, but I did fix a couple of similar plastic Q+Q movements, and they seem to be very finiky if they are not absolutely clean and free of grease and oils. I cleaned mine with lighter fluid and a cotton bud, and used the lightest oil I had on the balance pivots only, and that seemed to be sufficient. Any other oiling, particularly on the fork or escape wheel, seemed to be counter productive. The Tissot 2250 may be different of course.
 

Edited by AndyHull

Share this post


Link to post
Share on other sites
  • 0

Have checked all sorts of possible scenarions/areas/parts... Here's more observations:

- the movement would stop after a few minutes if the seconds hand was installed; remove the seconds hand and it ran all day without stopping (the seconds hand is attached to a long rod that goes down the center of the movement and into a gear)

- now it stops after a few minutes even if the seconds hand is not installed; I can restart the movement by jiggling the large white gear that is attached to the mainspring below it

- the hairspring doesn't seem to coil evenly when the movement runs; only half of it coils up while the other half only coils up a bit. (shouldn't it coil up in/out evenly?)

20191127_165258.thumb.jpg.226dc29dbe857fb8a9f6d0b6a89f49f2.jpg

 

Edited by Chopin

Share this post


Link to post
Share on other sites
  • 0

sorry to say this but this spring is not good to my standards. The spring should lay flat even if its not in the movement. it may have been stretched out at some point like a slinky making an arc (happens when its held upside down by the cock and balance slips out of the pivot hanging over the cock) and therefore the spring is not centered under the pivot. attach to the foot and hold it up letting balance hang. when looking at directly above the cock the coils should be centered under the cock hole jewel and wheel should be lay at parallel, if it looks like its off to the right or left or balance is titled then the hairspring is warped. this is most likely your issue and will explain why its running so fast. 

Share this post


Link to post
Share on other sites
  • 0

I was in two minds about that. The balance retaining pin looks relatively heavy, so I presumed that the reason the spring wasn't lying flat in the first set of pictures, could be down to that. I guess we need a side view of the balance in situ to see if it lies flat when fitted to the balance cock to be sure, but it does sound like the hairspring is not lying flat.

Share this post


Link to post
Share on other sites
  • 0

Hi the only true way to determine the flatness of the spring is to fit it in the watch correctly then look at it on the horizontal  in which case it should be perfectly flat, and when observed from above the coils beating evenly. as the photo shows there is a pronounced sag in the spring caused by the fixing stud dragging the spring  down at an angle

Share this post


Link to post
Share on other sites
  • 0

The hairspring stud slightly pulling the hairspring down was a bit weird to me as well but I too thought that it might be the weight.

When placed in the movement it seems to be flat/horizontal as it should. Nothing looks off...

I have taken the movement apart again (for the 10th-15th time...) and looked at 2 plastic gears that each had a tooth or two that didn't seem 100% pointy (think I corrected them but it didn't seem like they would influence good running of the movement) but I had done various tests and it didn't stop running before and I don't think that such an issue would cause a movement to run fast...

Put the watch back together and about 2 hours ago it ran at between +60 to +100 seconds (I don't have a timegrapher so have to do with an app but it seems to do an OKish job).

Measured it again and now it's at a constant +112 seconds/24h. I did wind the mainspring some more so I wonder if that may have influenced it a bit... (when it ran at +250 seconds it wasn't wound as much as it is now, though, so keep that in mind).

It doesn't seem to be stopping now but I haven't added the seconds hand which would always cause to stop it after a few minutes...

The regulator is in the middle as I don't want to influence anything in that area just yet... The stud can also be rotated to adjust the distance between spires of the hairspring and I've always had them evened out.

Also here's what I observed in the hairspring itself, the fact that it'll coil more in one side and less in the other. Shouldn't it coil evenly on both sides ? (by "coils" I mean the motion of expanding or coiling up; when the hairspring expands it'll expand in the left side but not much in the right side)

20191127_165258a.thumb.jpg.d579547f68a4bfbc44f56598645e8a8b.jpg

Share this post


Link to post
Share on other sites
  • 0

Hi  when the watch is powered down   i.e    stopped, are the coils evenly spaced then and where is the pallet/fork in relation to the inpulse pin, the pallet/fork with the watch at rest should be in the middle of the banking pins and the balance spring between the regulator pins.    The arm with the stud on it moves independently from the regulator this is so the beat error can be adjusted (difficult with out some form of instrumentation).   Down load the watch-o-scope software and run the lite version it will give you a lot of information as is. and enable you to set beat error with the appropriate lift angle installed and also give you a trace as to the performance of the watch   i.e  fast or slow and beat error.  The balance spring its self will only affect performance if it is damaged, gummed up and sticking badly adjusted, out of round, out of horizontal. So firstly we have to diagnose as to why the rate error exists, using the software will at least give you a clue and hopefully a few pointers.  By the way I have no affiliation with watch o scope other than I use the lite version as a preliminary check and have found it usefull for diagnosis of problens. I then  re check with a Horotec device for the final checks.     cheers

Share this post


Link to post
Share on other sites
  • 0
5 hours ago, Chopin said:

Also here's what I observed in the hairspring itself, the fact that it'll coil more in one side and less in the other. Shouldn't it coil evenly on both sides ? (by "coils" I mean the motion of expanding or coiling up; when the hairspring expands it'll expand in the left side but not much in the right side)

20191127_165258a.thumb.jpg.d579547f68a4bfbc44f56598645e8a8b.jpg

No. You would only expect hairspring to expand evenly on all sides if it has an overcoil. On a flat hairspring like this only the side opposite the stud and index would really expand.

Share this post


Link to post
Share on other sites
  • 0

It is true and well known that an overcoil hairsping breaths more evenly than a flat one, and maintaining concentricity improves isochronism. https://en.wikipedia.org/wiki/Balance_spring#Isochronism

A flat spring suffers from (the lack) of that especially when vertical with the breathing side down. Seiko used a "small" weight to win in the old times of Chronograph competitions againstthe Swiss. More modestly one can try to make some dynamic adjustment on the outer curve.

The middle part of this excellent article also discusses the same issue.
https://watchesbysjx.com/2019/06/master-dynconcentricityamic-silicon-hairspring-hong-kong.html

Share this post


Link to post
Share on other sites
  • 0
22 minutes ago, jdm said:

Seiko used a "small" weight to win in the old times of Chronograph competitions againstthe Swiss.

@jdm do you have any references for this? I have not come across this approach to addressing isochronism before and would like to read up on it.

Share this post


Link to post
Share on other sites
  • 0
4 hours ago, Marc said:

@jdm do you have any references for this? I have not come across this approach to addressing isochronism before and would like to read up on it.

Chronometer competition of course, sorry I was writing in haste.

https://www.ikigai-watches.com/interview-with-the-watchmaking-father-of-the-modern-mechanical-grand-seiko-mr-akira-ohira/5472

Edited by jdm

Share this post


Link to post
Share on other sites
  • 0

I think the hairspring looks ok. In the static state the coils appear concentric and I am of the opinion that the rather weighty stud explains it,s apparent lack of flatness.. I am wondering if there isn't a problem with where the hair spring is attached to the stud. if it is not formed correctly there, I think it would move  the h/s off center, causing you problem.

Edited by yankeedog

Share this post


Link to post
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.

Guest
Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  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.

Loading...

×
×
  • Create New...