Combined click + click spring not engaging ratchet wheel efficiently

[ifibrin]

I currently have an AS 577.301 that’s working pretty well, other than the combined click and click spring not engaging the ratchet wheel efficiently. What I mean is that when I wind the watch, the click still engages the ratchet wheel when you release the crown, but the click springs back weakly, allowing the ratchet wheel to lose wind by a few teeth of the ratchet wheel before the click stops the ratchet wheel from unwinding. This is seen by the crown springing back by a bit more than normal when you wind it, although the watch can still be wound by sufficient turns of the crown. I can also wind the crown more easily by holding the crown still and turning the watch.

Could this be because of a weak combined click + click spring, or worn ratchet wheel teeth not engaging the click properly? I have attached a few photos highlighting the parts mentioned, but they are not from the movement I have.

Edited October 31, 2021 by ifibrin

[canthus]

Is the end broken off (RHS of pic)?   See link for one on bay to compare.

 

https://www.ebay.co.uk/itm/124741208883

[watchweasol]

Hi  as Canthus said spring broken,  Attached techsheet.  part is 51.120  (434) hope that helps.  cheers

AS 577.301 and eta 277.001 (1).pdf

[ifibrin]

That’s not actually the photo of the click in the movement I have, but of a picture I found on the internet to illustrate the part.   The close up photo of the click is supposed to be a spare part being sold on eBay, but it looks pretty similar to the one in the as movement I have.

[ifibrin]

I will admit that the click does look slightly different from the part @canthus posted, but it could be a minor revision difference? I noticed that click springs sometimes get changed in shape throughout the manufacturing period.

Nevertheless it’s likely to be due to the click, and I will investigate further.

Edited October 31, 2021 by ifibrin

[HectorLooi]

If you post photos from your actual watch, it will make diagnosing the problem much easier.

[ifibrin]

As an update, I managed to resolve the issue. It turns out the click spring was bent because I had pushed it too far in the other direction when releasing the power from the mainspring.

I bent the click spring slightly in the other direction, and now the click spring/ combined click engages the ratchet wheel very well. Turns out the weak point in this combined click design is when releasing the mainspring power.

Another movement with a weak combined click design is the ETA 2671, where an odd shaped spring acts as a click to prevent reverse unwinding of the ratchet wheel. There’s no good way to release mainspring power, other than to let the watch wind down by itself.

Edited December 18, 2021 by ifibrin