Hairspring in regulator pins

[BobG]

When I remove and vkesn the balance, especially vintage, the hairspring falls out from the regulator pins.  When I reinstall the balance I was getting poor numbers and when I looked the hairspring was outside and not between the pins. 
I’m new to watch servicing and is there a technique for reinstalling the balance to insure the hairspring remains between the regulator pins? 

[Nucejoe]

Is it a regulator pin & boot or etachron regulator ?  Most vintage are reg-boot, turn the boot.  

 

Edited April 9 by Nucejoe

[Neverenoughwatches]

4 hours ago, BobG said:

When I remove and vkesn the balance, especially vintage, the hairspring falls out from the regulator pins.  When I reinstall the balance I was getting poor numbers and when I looked the hairspring was outside and not between the pins. 
I’m new to watch servicing and is there a technique for reinstalling the balance to insure the hairspring remains between the regulator pins? 

The hairspring would usually be contained between the pins. Sometimes it's a pin and a boot that has a  lip that closes over the end of the pin . Sometimes it's a looped wire, othertimes an Etachron system.  What do you have ?

[BobG]

One was on a Bulova 10BC and the other a Hamilton vintage. Neither had a boot or wire. 
It’s not as common for me on the Ettachron but it has happened. 

[mbwatch]

13 minutes ago, BobG said:

One was on a Bulova 10BC and the other a Hamilton vintage. Neither had a boot or wire. 
It’s not as common for me on the Ettachron but it has happened. 

Ah - the Bulova 10BC just has two vertical pins, no boot. I just finished a project with that movement too. This is what you will find on most movements from the 1940's and older. On larger pocket watch movements with stout hairsprings, as long as the spring is perfectly formed it will usually land directly between the pins when installed.

But on a small movement like the 10BC with a small regulator, the hairspring may land outside of the pins. It is easy to put in once the balance is mounted. Take your finest oiler (clean!) and just push down VERY gently on the hairspring right beside the regulator. As soon as the spring reaches the ends of the regulator pins it should jump in between them and land where expected. But you have to be really gentle with this or you will bend the spring out of flat. It is much more delicate on a small movement like yours. If the hairspring is not correctly formed, it may not jump in between the pins and if it does, it still may be incorrectly placed and not centered between them.

It is of course best to place the spring between the pins at the moment you are installing the stud into the balance cock, but that isn't always as easy as it sounds.

[nickelsilver]

On movements with overcoil hairsprings there won't be a "boot", just the two pins. The Bulova 10BC has an overcoil, as I would imagine a vintage Hamilton would. Most of the time the spring stays in; if it doesn't it's simple enough to get back in place, just double check the spring is flat and centered.

[LittleWatchShop]

I always rotate the regulator pins as far away from the stud as possible while installing the balance/hairspring.  That gives more flexibility to manipulate the hairspring without risking bending it.

Edited April 9 by LittleWatchShop

[BobG]

I did gently manipulate the spring back between the pins once installed but I thought there might be some technique either before or during the install to keep the spreng from falling out. 

Onto an Etachron related question. When I install a new balance assembly onto the balance cock what is the best way to get back onto the movement?
I have tried placing the balance assembly onto the cock when it is lying on the bench, this method is easiest to get the spring in between the pins since I turn the regulator block to give me max opening but when I flip the cock over to install it the balance falls off. Last time I placed the balance assembly onto the movement and gently lowered the cock into place over it and the seated the spring and the stud.  What method do you use?

[mbwatch]

3 hours ago, BobG said:

What method do you use?

For small movements of any type and large ones where the stud has to fit into a hole of some sort, I stick the balance cock on its back to a steel bench block with a tiny bit of rodico, such that it overhangs the bench block. I Put the balance in such that I can lower the stud into its hole, and then because the cock overhangs the bench block I have access to tighten the stud screw underneath. Then remove the overhang and support the whole thing on its back if I have to close a regulator boot too.

For pocket watches that have an easier receptacle for the stud, like Waltham's wedge shaped indent that a screw tightens down over, or Hamilton's style where the stud slots in from the side, I put the balance in its jewel on the plate then lower the cock over it. The studs on those tend to jump right into position then for the screw to be tightened.

[BobG]

Your method works well if the stud had a screw but the Etachron is press fit and without the cock or bridge being supported I can’t press hard enough to seat it.  So my question is more about how to deal with replacing the balance assembly on the Etachron 

[HectorLooi]

I have never experienced this problem before. Even when the balance is allowed to hang freely on a balance stud, the hairspring should not free itself from the regulator pins.

Has your hairspring been damaged by excessive force and ended up getting coned?

Etacron studs can easily be mounted by pressing it in with the back of the tweezers. The balance cock can be placed upside down on the table or replaced back into movement to do this.

I think Alex Hamilton has a nice video on YouTube showing how it's done.

[BobG]

If you look at the Bulova 10BC movement there is nothing to keep the spring between the pins when the spring is extended. 
Alex does have a video and he says to set the new balance assembly on the cock when it is upside down on the bench. Place the stud at the opening of the arm end locate the spring between the regulator pins. He the says pick the entire cock up and set it into the movement. Secure the cock and press fit the stud into place. 
However when I do this and pick up the entire assembly by the cock the balance assembly  doesn’t stay connected. 
I’ve also tried pressing in the stud while upside down on the bench but it takes a lot of force the I can’t easily get the butt if the tweezers under the balance wheel. 
What do you do so that the balance assembly stays connected to the cock when the stud is not pressed in? 

Edited April 11 by BobG

[HectorLooi]

If you watch this video, the spring should stay within the regulator if the spring is not damaged. Even on really vintage movements where the regulator is just two brass pins, the hairspring never comes out of the regulator.

Are you sure your hairspring has not become coned? Could you post some photos. 

If you are still worried that the hairspring will slip out, move the regulator arm as close to the stud carrier as possible. 

[Neverenoughwatches]

A lot of questions have been answered.....but we haven't seen a picture of what you're looking at yet

[JohnR725]

On 4/9/2025 at 7:12 AM, nickelsilver said:

just double check the spring is flat and centered.

Very important not to assume and always double check.

3 hours ago, HectorLooi said:

the spring should stay within the regulator if the spring is not damaged. Even on really vintage movements where the regulator is just two brass pins, the hairspring never comes out of the regulator.

I like this the word never that's an absolute absolutely never except sometimes they do. It depends upon a whole variety of things. It really would be nice though if it never happened but unfortunately it does.

5 hours ago, BobG said:

If you look at the Bulova 10BC movement there is nothing to keep the spring between the pins when the spring is extended. 
Alex does have a video and he says to set the new balance assembly on the cock when it is upside down on the bench. Place the stud at the opening of the arm end locate the spring between the regulator pins. He the says pick the entire cock up and set it into the movement. Secure the cock and press fit the stud into place. 
However when I do this and pick up the entire assembly by the cock the balance assembly  doesn’t stay connected. 
I’ve also tried pressing in the stud while upside down on the bench but it takes a lot of force the I can’t easily get the butt if the tweezers under the balance wheel. 
What do you do so that the balance assembly stays connected to the cock when the stud is not pressed in? 

This by the way is really confusing I don't suppose we can get a picture? I may swipe a picture off the Internet and maybe you can explain help it with my confusion? Notice I put a little mark next to a screw? As I said your quote is really confusing normally when the balance bridge is upside down to place the entire balance wheel onto the bridge and get the stud to go back into its whole and you tighten the screw then the stud will  stay in place they could flip it over and put in the watch. So I don't understand it doesn't stay in place and why are you pushing so hard? We really do need pictures and a better description

6 hours ago, BobG said:

Your method works well if the stud had a screw but the Etachron is press fit and without the cock or bridge being supported I can’t press hard enough to seat it.  So my question is more about how to deal with replacing the balance assembly on the Etachron 

Normally on a etachron  you would not remove the stud at least for cleaning it only be removing it if you're replacing the entire balance assembly? We really need pictures and better descriptions of exactly what you're trying to do and exactly how you're trying to assemble your balance system?

 

[BobG]

Regarding the Bulova 10BC, it's all back together and running. I gently reset the spring between the pins after I remounted the cock within the movement. 

Regarding the Etachron, I am replacing the complete balance assembly.  I release the stud from the carrier arm and open the regulator pins when the cock is secure to the movement. I then remove the cock and balance and place the cock upside down on my bench. I lay the new balance assembly over it and align the stud  and insert the spring between the pins. 

Now, when I pick up up the balance cock to place it back into the movement the balance assembly falls away because the stud is not secured.  What method do you use to get the new balance assembly back into the movement? It takes a bit of pressure to secure the stud into teh carrier arm and is not easily down on the bench when the cock is not secured. 

OK, I watched Alex's video again and what he does when replacing the balance to the movement is pick up the complete balance assembly with the cock in his tweezers so the spring is not hanging down and  then place the entire cock and assembly into the movement. He is not trying to align the impact jewel at his point just the pivots so that he can secure the cock and press in the stud. 

 

[JohnR725]

4 hours ago, BobG said:

I watched Alex's video again

Interesting video he didn't get the history quite right and I learned something new

So what did I learn new well at about six minutes and 30 seconds I learned something interesting which I didn't realize you would normally ever have to do? Apparently you can use a razor blade to split the regulator pins the at the hairspring out and then of course you do have to remember to close it again. Which is quite fast dating because I don't actually think you're supposed to be doing this at all.

 

[BobG]

OK, I watched Alex's video again and what he does when replacing the balance to the movement is pick up the complete balance assembly with the cock in his tweezers so the spring is not hanging down and  then place the entire cock and assembly into the movement. He is not trying to align the impact jewel at his point just the pivots so that he can secure the cock and press in the stud. 

 

Some background: The Seiko NHxx movements are very common for modding or building custom watches. They are robust but mass produced. When modders receive them, being tinkerers that they are, they put it on their Timegrapher and try to regulate the timing. Sometimes they slip and other times the regulator pins and hairspring are not aligned very well and any adjustment causes the harispring to kink and then the watch is near imposible to regulate. 
I few modders have sent me their NH35 movements that were "broken" assuming it was the keyless works jammed up but in 4 of the 5 I looked at it was the hairspring was bent, kinked or twisted. I could straighten them enough to get the movement going but the amplitude never came back. That's partially because I am not very good at hairspring work. So, I ordered a few complete balance assemblies (spring, wheel, staff) from AliX for $5.64. 
This is why I am removing and installing new Etachron balance assemblies. I have not had a problem removing or re-inserting the hairspring into the regulator block between the regulator pins when the cock is out and  it is lying face up. I do need to use 7X magnification though. It is the reinserting the stud into the carrier that has caused me problems. It is tough when the cock is not mounted but getting it mounted when the stud is not secure was puzzling. Now I see I'm supposed to grab the balance with the cock as one piece so the spring can't fall out. 

[mbwatch]

Ah, now I understand what you've been getting at; mounting the balance cock to the mainplate before the Etachron stud has been snapped into place and secured. 8:35 in the video for anyone else who has had trouble following what the challenge was here.

[Neverenoughwatches]

6 hours ago, BobG said:

, I watched Alex's video again and what he does when replacing the balance to the movement is pick up the complete balance assembly with the cock in his tweezers so the spring is not hanging down and  then place the entire cock and assembly into the movemen

Thats a good way to bend a top balance pivot, lol...well it can be if you're not being careful. When I get noodle hairsprings, I support the balance with a piece of paper while carrying the cock, and help it into position.

[Nucejoe]

On 4/9/2025 at 5:43 PM, LittleWatchShop said:

I always rotate the regulator pins as far away from the stud as possible while installing the balance/hairspring.  That gives more flexibility to manipulate the hairspring without risking bending it.

Great.    

  A+

 

19 hours ago, BobG said:

I'm supposed to grab the balance with the cock as one piece so the spring can't fall out. 

Right