2836-2 pallet fork

[azerbyjam]

I've been doing the TZ course and have just re-built an ETA 2836-2 for the third time. On my first attempt I must have dislodged one of the stones in the pallet fork and as a result couldn't get the movement to work but necessity being the mother of invention, I used the fork from a now defunct SW200 that I had lying around because as far as I could tell they were the same and low and behold the movement ran, but with one small problem, as soon as I turned the movement dial side up, it stopped.

There was clearly something amiss and as I was using a foreign part my suspicion fell there and sure enough close examination shows there is a difference in the pivots, see pic

Fork on the left is the ETA part (missing one stone) and on the right is the Sellita SW200. The difference in the pivots is obviously allowing some shift when the movement is inverted which is enough to move the stones out of alignment with the teeth on the pallet wheel which of course stops the movement. Clearly I need a new pallet fork 'cause trying to re-set that missing stone looks nigh on impossible to me and this brings me to my question. Does anyone know if this part comes with the pallet stones already installed, the ETA part number is 2801 710 and is listed on Cousins website, I'm just not clear about the stones and I've been waiting a week now for Cousins to reply to my email, appreciate any help guys

BTW if you havent already done so give the TZ course a go, its a fantastic feeling taking a movement completely apart and putting it back to running condition, I'm pretty sure if I can do it anyone can

[Guest carlsbadrolex]

I dont know if the stones come pre-installed... But if you want an entire fork with stones installed let me know. I have a few here and could easily spare one.

[RWG Technical]

It does come with the jewels installed.

I have not had any luck with SW200 parts and ETA parts, they are totally different.

So glad to hear your enjoying the TZ course, with Offshore offering the CD with everything on it, there is no reason to not take the course.

RG

[azerbyjam]

Thanks for the replies.

@carlsbadrolex: I did eventually get a reply from Cousins and I have since bought the part, thanks a lot for the offer though.

@The Zigmeister: even with the ETA fork installed I still have the syptoms described in my first post, any thoughts?

[RWG Technical]

It could be a number of problems.

My first guess would be a broken pivot on the balance staff. Remove the balance kock jewel, and with a 10X loupe, check if the pivot is visible.

If it's not the pivot, then my guess would be something touching the balance, maybe the pallet or the hacking lever...

It's going to take some troubleshooting to find the problem, but it's a great learning excercise.

RG

[azerbyjam]

Thanks for your input The Zigmeister, I'll take another look and as you say it's all a good learning experience.

[azerbyjam]

UPDATE

Happy to report this problem is now solved.

As The Zigmeister suggested a close inspection of the pallet revealed the problem, the balance spring had come out of the regulator, see picture, more than likely due to some less than gentle handling by me. Anyway I put it back where it should be and carefully placed the balance assembly back into the movement and everything is now working as it should

Picture borrowed from the TZ course material and the regulator to which I refer is the part numbered 6.