Attaching a stud to the balance bridge

[kd8tzc]

I'm working on my Hamilton 987A watch, and I had some difficulty with the hairspring but I have resolved all of that and I am not looking to reattach the balance assembly to the balance bridge.  The movement has a balance bridge that you just insert the stud into a small hole on the bridge and tighten a screw... sounds simple enough, but what is the best way to get the stud back into the hole?  Should I place the balance assembly into the movement, then place the bridge back on it, screw it down, and then insert the stud to the hole and tighten, or is there a better way to do this?

Thanks

 

John

[Nucejoe]

5 hours ago, kd8tzc said:

  Should I place the balance assembly into the movement, then place the bridge back on it, screw it down, and then insert the stud to the hole and tighten, or is there a better way to do this?

 If there is enough space so you can get the stud inserted into the hole like you say,  why not .  But such space isn't available in some calibers, in such cases you should

1- Lay the cock on bench upside down.

2- Open the regulator slot enougn for spring insertion into it, Close the slot.

3- Tighten the stud screw if you feel enough contral over the task, if not, grabe the cock and stud in your twe5ezers, flip it over to instal onto the bare mainplate, then tigten stud screw. 

 Now is the time to make some adjustment to the coil, level it, minor adjustment for coil concentricity, check if balance swings freely, so on.

This all comes before reassembly. Make a habiit of always doing adjustment to the coil, check the balance swing etc so you are sure balance and coil are OK before you instal it. 

Rgds

Edited August 18, 2023 by Nucejoe

[kd8tzc]

Thanks @Nucejoe... what do you recommend using to open and close the regulator slot?

I agree, there is hardly any space to do these things with it in the movement, so that was the reason for asking.  Being that it is very wiggly, that is the biggest issue I see when doing this outside the movement... but there is a lot more room, and I would think it would be easier to insert the stud into the receiver on the cock when upside down.

[Neverenoughwatches]

15 minutes ago, kd8tzc said:

Thanks @Nucejoe... what do you recommend using to open and close the regulator slot?

I agree, there is hardly any space to do these things with it in the movement, so that was the reason for asking.  Being that it is very wiggly, that is the biggest issue I see when doing this outside the movement... but there is a lot more room, and I would think it would be easier to insert the stud into the receiver on the cock when upside down.

As Joe stated, there isn't always enough room to fit the stud into position when the cock is mounted. The staff could be at risk if you try to squeeze something into position. If you can have the cock held in someway that would make things a bit easier.

[kd8tzc]

58 minutes ago, Neverenoughwatches said:

If you can have the cock held in someway that would make things a bit easier

Any suggestions? 

[Nucejoe]

1 hour ago, kd8tzc said:

what do you recommend using to open and close the regulator slot?

Have no idea  what type of regulator slot does hamilton 987A have?  

Someone would tell us soon .

On overcoils though the slot must be fully closed. 

 

 

 

[kd8tzc]

The 987A is an overcoil.

[Neverenoughwatches]

52 minutes ago, kd8tzc said:

Any suggestions? 

This evening i was pinning a hairspring to a fixed stud. I used a small pair of locking pliers to hold the cock steady. That bit was easy, making a new brass pin after misplacing the original 4 weeks ago was a little less so.

[kd8tzc]

Okay... I do have a mini pair of vice grips, but I would be a little concerned about the teeth on the jaws marring up the bridge.  I'm sure I could always put a scrap piece of leather in the jaws though, or just use my hemostat, although the bridge may be too thick for the hemostat.

I did see this online, which is rather cool looking... but it has teeth in the jaws too.

 

Edited August 19, 2023 by kd8tzc

[LittleWatchShop]

This issue can be a challenge.  I have made a jig that holds the balance cock while attaching the hairspring stud.  I show the "best case" picture here.  This is a balance cock from a Vulcain Cricket.  Since it has two holes, it mounts on the jig nicely.  For the majority of cases, you do not get this luxury.  So, I pin the hole and then a pin on the leeward edge of the cock so that it is held in place (more or less) while pressing against the screw to tighten.

To be candid, this jig works somewhat, but not great.  I am still searching for an ideal solution.

[Neverenoughwatches]

13 minutes ago, kd8tzc said:

Okay... I do have a mini pair of vice grips, but I would be a little concerned about the teeth on the jaws marring up the bridge.  I'm sure I could always put a scrap piece of leather in the jaws though, or just use my hemostat, although the bridge may be too thick for the hemostat.

I did see this online, which is rather cool looking... but it has teeth in the jaws too.

 

A piece of chamois should be ok. Its not to grip tight,  just to hold the cock while you fit the stud. This is the idea i had in mind. You might even be able to fit the cock upside down on the movement. 

20 minutes ago, kd8tzc said:

Okay... I do have a mini pair of vice grips, but I would be a little concerned about the teeth on the jaws marring up the bridge.  I'm sure I could always put a scrap piece of leather in the jaws though, or just use my hemostat, although the bridge may be too thick for the hemostat.

I did see this online, which is rather cool looking... but it has teeth in the jaws too.

 

There is also something called a studding table. 

[JohnR725]

19 hours ago, kd8tzc said:

what do you recommend using to open and close the regulator slot?

one of the problems in watch repair is there lots and lots and lots of things that are entirely different. His set of rules were a generalized rule not an exact rule to follow. You have an over coil hairspring you do not want to open up the regulator pins they will work just fine the way they are and closing them when the hairspring is in usually leads to hairspring damage.

2 hours ago, kd8tzc said:

Okay... I do have a mini pair of vice grips, but I would be a little concerned about the teeth on the jaws marring up the bridge.  I'm sure I could always put a scrap piece of leather in the jaws though, or just use my hemostat, although the bridge may be too thick for the hemostat.

I did see this online, which is rather cool looking... but it has teeth in the jaws too.

yeah they make really big industrial vices you could grab it sideways and industrial device but laying it on top is something and doing it on your bench is really the best way any time you're dealing with the balance wheel hairspring and the balance bridge out of the watch there can be issues and seemingly nice things like using an industrial vice to hold that might not be the best way and know nobody said industrial vice but me but still you want to be careful which are doing basically this is a issue of you need to have some practice like everything else in watch repair

2 hours ago, Neverenoughwatches said:

There is also something called a studding table. 

interesting choice for the task very interesting. So were going to use something for holding the stud the same stud that he wants to insert into the bridge will now be held by this tool meeting it's impossible to insert it in the bridge. This tool is for holding the stud for pinning the hairspring and hopefully is still attached where it's supposed to be?

I still find the best way is I raise it up a little off the bench with a piece of pith wood yes you be careful the bridge can move around so I hold it with my finger. Then if you're not in the room of other people you can swear a lot unfortunately I too many people around. Biggest pain is usually is tightening up the stud screw and occasionally will think it's typed when you flip it over you find it wasn't enough and then you have to start over again.

Trying to put the balance wheel in the first and then put the bridge is usually very problematic there isn't enough room usually to get the stud under the bridge and there's just too much stuff going on it will lead to disaster usually although like everything else in watch repair there are lots of under some circumstances that might actually be a good plan just not in this particular case.

[Neverenoughwatches]

30 minutes ago, JohnR725 said:

interesting choice for the task very interesting. So were going to use something for holding the stud the same stud that he wants to insert into the bridge will now be held by this tool meeting it's impossible to insert it in the bridge. This tool is for holding the stud for pinning the hairspring and hopefully is still attached where it's supposed to be?

Ah yes that was test John, I'm really pleased to inform you that you passed  congratulations

[dadistic]

The only time that I've seen it recommended that the balance be put in place first and then the cock placed on top is with certain Seiko movements. The ones with the etachron style regulator, as the stud snaps in place, there is no screw.  Still makes me nervous doing it that way.

[kd8tzc]

Well, I have everything back together.... watch started beating, but as soon as the bridge screw is tightened, it stops.  So this is too tight for some reason.  I know with the old Soviet watches they would shim the bridge, but I would rather not do that if I can avoid it, so any suggestions, I would appreciate.

[RichardHarris123]

The only alternative to shimming is to move the jewel. 

[JohnFrum]

These Bergeon 2769 Balance Bridge Holders come up occasionally on ebay

[HectorLooi]

I'm sure it won't be difficult to come up with some hold down tool made from scrap pieces of brass, plastic or hard wood.

It would be interesting to see what designs member could come up with.

[LittleWatchShop]

On 8/19/2023 at 7:20 PM, HectorLooi said:

I'm sure it won't be difficult to come up with some hold down tool made from scrap pieces of brass, plastic or hard wood.

It would be interesting to see what designs member could come up with.

Easy enough with a 3d printer...and I have thought about it, but there are so many variations of balance cocks sizes and shapes.