Can I tighten this cannon pinion?

[thor447]

I am working on an ETA 2782 and the hand setting is very loose.  I got the movement back together and found that while the seconds hand ticks along just fine, I get no movement from the hour or minute hands.  I'm sure that this is related to the cannon pinion.  I don't feel any resistance at all when turning the crown in setting mode.  Since this is a combo driving wheel/cannon pinion, is it possible to tighten the cannon pinion to the driving wheel, or is my only option to find a replacement part?

I'd appreciate any advice.

 

[HectorLooi]

It's not advisable but I've done it before. You need to remove the centre tube first, then use a screwdriver blade to wedge the prongs on the wheel to tighten it.

Good luck.

[thor447]

1 hour ago, HectorLooi said:

It's not advisable but I've done it before. You need to remove the centre tube first, then use a screwdriver blade to wedge the prongs on the wheel to tighten it.

Good luck.

Thanks for the reply @HectorLooi, it makes me feel better about what I just did!  I was reading and found an article where it said the same thing, that they aren't really serviceable and must be replaced if they get too loose.  Well, I figured there wouldn't be any harm in trying to fix it because I'd just order a replacement if I damaged my current part.  

Looking at mine under high magnification, I saw where the 3 brass prongs sat inside that gap just behind the roll crimp on the back side of the cannon pinion.  There was a lot of vertical play, which I believe contributed a lot to how loose it was, along with the brass prongs not seating fully in that groove any longer.  I slightly adjusted the prongs inward.  Afterwards I used my recently acquired antique staking set to basically press down a bit more on the old roll crimp with a curved stake, lowering that crimp closer to the brass prongs.  It still has movement, but wasn't as free spinning as it was previously. 

It seemed to do the trick and the watch is up and running now!  I feel the slightest resistance when setting the hands, and the minute & hour wheels are moving nicely.  I'm pretty happy about it.  I felt like a bit of a 'watchmaker', fixing the part rather than just replacing it.  I saved a bit of money and probably a lot of time trying to source a replacement part as well.

Edited October 6, 2022 by thor447

[Neverenoughwatches]

5 hours ago, thor447 said:

Thanks for the reply @HectorLooi, it makes me feel better about what I just did!  I was reading and found an article where it said the same thing, that they aren't really serviceable and must be replaced if they get too loose.  Well, I figured there wouldn't be any harm in trying to fix it because I'd just order a replacement if I damaged my current part.  

Looking at mine under high magnification, I saw where the 3 brass prongs sat inside that gap just behind the roll crimp on the back side of the cannon pinion.  There was a lot of vertical play, which I believe contributed a lot to how loose it was, along with the brass prongs not seating fully in that groove any longer.  I slightly adjusted the prongs inward.  Afterwards I used my recently acquired antique staking set to basically press down a bit more on the old roll crimp with a curved stake, lowering that crimp closer to the brass prongs.  It still has movement, but wasn't as free spinning as it was previously. 

It seemed to do the trick and the watch is up and running now!  I feel the slightest resistance when setting the hands, and the minute & hour wheels are moving nicely.  I'm pretty happy about it.  I felt like a bit of a 'watchmaker', fixing the part rather than just replacing it.  I saved a bit of money and probably a lot of time trying to source a replacement part as well.

Well done Thor

[nickelsilver]

These can be tricky to tighten. Sometimes the "ears" will bend, but they aren't particularly elastic and can break quite easily. If you punch as indicated in the pic with a very small dome faced punch it will move the metal over, doesn't break and usually does the trick.