ETA 2801-2 balance cock assembly

[KellyZ]

Hello,

Newbie here that recently finished Mark's classes. I have a 2801-2 movement that was missing the upper Incabloc setting on the balance cock... there was just a hole in the cock. I got a complete setting with the seat, hole jewel, cap jewel and spring. I figured out the Etachron stud drama, removed the hairspring from the cock and pressed in the setting. I was feeling pretty smart at that point and got to what I thought was going to be the easy part... reinstalling the stud support, lower regulator index and upper indicator index. Per the 2801-2 datasheet, I think these are supposed to fit around the Incabloc setting which protrudes above the balance cock by a couple of millimeters. The upper index, which goes on last, is split (presumably so it can expand to fit) and has a lip in the inner circumference which protrudes down (presumably to friction fit against the inner circumference of the lower index which is directly below).

I put all the parts in place and grip the cock with heavy tweezers laid across the setting and below the cock. If I squeeze, I sometimes hear the parts snap into place, but they are not really secure and if I try to manipulate the upper index it all comes apart so my approach is clearly wrong. I did find a post in the walkthrough section of the forum which discussed this, but it didnt really go into detail on this part of the procedure. Has anyone out there done this and willing to offer some tips? Thanks in advance for your help.

[Kalanag]

It should look like that:

 

[KellyZ]

Yes, exactly. The upper index is clearly visible. It is the “regulator pointer” and if you look closely, you can see the split in the ring at th 9 O clock position. Directly beneath is the lower index and you can see the tab with the piece that clamps the spring sticking out at the 10 O clock position. Underneath it all is the stud support and the tab which has the Etachron stud holder is sticking out at 8 O clock. All three are assembled around the shock setting… but still trying to figure out how they are held in place.

[Kalanag]

The chamfered block should hold the upper index which is chamfered also. Could the index be placed upside down in your case?

 

[KellyZ]

hmmm... that might be my problem. I might have the wrong setting. The side of mine appear to be straight. Will examine later under higher magnification and report. Thanks, this is helpful.

[KellyZ]

My setting is indeed chamfered. It is barely perceptible under 10X magnification, but I can see it clearly under 20X. I am still not getting anywhere trying to press in with tweezers. I thought about using my staking set but I dont have a punch with a hole wide enough to press the circumference of the index ring without pushing on the setting. I am now thinking that I should remove the setting, place the stud support and indexes on the balance cock, put the setting on top, then press the setting in. This will be incredibly finicky (for me) to do, but I am going to walk away for a day to calm my nerves and try again.

[HectorLooi]

This shouldn't be that difficult. I just did something similar a couple of days ago. It was a Russian Slava 2414. And that had an extra beat error corrector.

I remove the balance completely and simple aligned everything and press it in with my bare hands. After all, the balance cock hasn't been cleaned yet.

Slip in the regulator at the base of the fork, then using your thumbnails to press on boths sides of the fork, working your way up to the open ends. It should click into place quite easily. 

[KellyZ]

Unfortunately there is a sad end to this story. I removed the setting and placed the stud support, lower index and upper index loosely on the cock. I then put the setting on top of all this and pressed it into place with tweezers. I could hear it snap into place. I then gently pressed a little more with a jewelling tool to ensure it was flat. It looked good and appeared secure at that point. I put the balance in the movement and then the cock. At this point I was in the process of pushing the stud back into the stud support and the whole thing went flying. The upper index is somewhere in low earth orbit, nowhere to be found. Until I find, or come across a replacement, I will have to shelve this effort. I am not really concerned about the movement, it does not have any value to me but I do wish I was able to work through this to a final solution.

[grsnovi]

25 minutes ago, KellyZ said:

The upper index is somewhere in low earth orbit, nowhere to be found.

Those of us new to this past time seem to share an affinity for launching things into near and far environments. It's how we learn.

I was recently replacing the upper jewels on a 110 year-old Elgin balance cock and while doing so shot the whole balance out of control and ended up with a tangled hairspring that I only made worse by trying to untangle it.