Broke my new balance staff during staking..

[BillM]

Hi all,

I finely got a staking set and have disassembled the balance from a 1909 16s Hampden pocket watch.

During the riveting step of my new balance staf, I broke the staf. Not just the pivot, but the whole shaft!

I was very careful to fit the shaft into the plate hole of the staking tool, made sure everything was flat and believe I chose the correct stakes to rivet the staf in place.

 I'm guessing I just hit the staking tool too hard, I didn't even get to using the flat stake as the staf broke after the 3rd hit of the hammer.

Looking at the riveted area, it's clear that its a good, but maybe over staked riveting job.

I did need to use a small drill to push out the broken shaft from the staking plate, once out I examined the staking plate and noted quite a bit of debris in the holes. (I've cleaned the staking plate sense)

Am I missing something?  Is really that easy to break a shaf during this process?

 

 

[ManSkirtBrew]

I assume this is a vintage staking set? Based on the fact that the pivot is also broken, I'm going to guess that there was some debris inside your stake that put enough lateral force on the staff to snap it off.

I know my set had bits of metal stuck in all the holes of the plate, so I wouldn't be surprised if there was debris in your stakes.

[JohnR725]

13 hours ago, BillM said:

Is really that easy to break a shaf during this process?

apparently in your case it was and as somebody else noted what happened to the pivot?

Before we even get to the staking set use as a reminder when you get a replacement staff you want to measure it and verify this exact same size as the original staff you took house. Typically with vintage or all American pocket watches there can be variations. Typically whatever catalog you're looking at may not list all the variations. So you want to make sure that you have the right size staff otherwise other unpleasant things can occur

I really hate to use my imagination because that is a very bizarre broken staff. It would've really been nice to have pictures of what you're trying to do

12 hours ago, ManSkirtBrew said:

I assume this is a vintage staking set? Based on the fact that the pivot is also broken, I'm going to guess that there was some debris inside your stake that put enough lateral force on the staff to snap it off.

I know my set had bits of metal stuck in all the holes of the plate, so I wouldn't be surprised if there was debris in your stakes.

great questions. If it's a newly acquired vintage staking set or basically anything other than a brand-new staking set you do want to check everything out. Especially the base plate the staking set often times things get lodged in their.

The other thing you want to be careful doing is making sure that the base and the punch itself exactly line up I'm wondering if maybe you are slightly out of alignment? this is why before you lock the lower played in place you have them punch that comes down that goes into the whole typically a very pointy punch and then with that pressed in place you can tighten the base plate otherwise there's always the chance is going to move and then it moved any whacked it that might be the reason fractured there's the other problem of how well was the original balance staff heat treated.

13 hours ago, BillM said:

I'm guessing I just hit the staking tool too hard, I didn't even get to using the flat stake as the staf broke after the 3rd hit of the hammer.

Looking at the riveted area, it's clear that its a good, but maybe over staked riveting job.

the normal procedure would be more than one punch. Usually need a couple of punches to spread the rivet out. Then you can follow up with the flat price to make sure of these nice and flat.

 

[nickelsilver]

The fact you had to use something to push out the broken piece is important. When choosing a hole in the plate, the staff should be a free fit. Not tight, not sloppy, definitely some freedom. Then as John mentions, alignment is very important. Some alignment punches are bent. Then, your round and flat face punches should have- some freedom. If they are a super close fit, but free, go the next size up.

 

All this freedom adds up to things staying flat during the rivetting process. My take on your situation is the staff was a snug fit in the plate, and you used a close fitting punch, and things literally went sideways when the hammering started.

Edited August 15, 2023 by nickelsilver

[BillM]

Thank you all for the input, much appreciated.

Yes the staking set is vintage, and I had not taken apart and cleaned the staking base before using it.  When I did take it apart there was a ton of crap in all the holes.  
 

I did use the alignment stake to be sure everything was lined up and I even checked the alignment stake for straightness.  
 

The hole I chose for the staff was not tight, but was not very loose either but the stake I chose was a very close fit.  

I measured the old and new staff and found a .0005” difference maximum and figured that was close enough, besides, My old lathe is not accurate enough to correct this.

I have ordered two more new staffs and will proceed with much more caution this next time around.   
 

I did note that the roller table fits loosely and will need the hole closed up a bit to work.  So that’s another issue I’ll need to address. 

[oldhippy]

Did you hit it with a lump hammer? You should always make sure the stakes are clean, in other words any thing that has a hole in your staking set make sure its clean. Providing you centered it before riveting it should have been fine providing you used the corset punch, always make sure you use the best fitting punch. 

[BillM]

2 hours ago, oldhippy said:

Did you hit it with a lump hammer? You should always make sure the stakes are clean, in other words any thing that has a hole in your staking set make sure its clean. Providing you centered it before riveting it should have been fine providing you used the corset punch, always make sure you use the best fitting punch. 

What is a “lump hammer”?  Never heard that term before.  
I don’t know what a corset punch is either. 
I used a round nosed punch that fit very close over the shaft of the staff. 

Edited August 15, 2023 by BillM

[oldhippy]

Here you go. 

[RichardHarris123]

5 minutes ago, oldhippy said:

Here you go. 

Disappointed in you @oldhippy, you could of at least chosen a good quality lump hammer.  hehe. 

[rehajm]

corset punch sounds interesting- if it's for removal I'm all for it!

[oldhippy]

21 minutes ago, RichardHarris123 said:

Disappointed in you @oldhippy, you could of at least chosen a good quality lump hammer.  hehe. 

I'll try to do better next time.

[LittleWatchShop]

I busted a pivot the other day because I grabbed an unchecked punch that was blocked.  Grrrr...I was mad.  Such an easy thing to avoid.

Edited August 16, 2023 by LittleWatchShop

[BillM]

57 minutes ago, oldhippy said:

Here you go. 

Bwhahahaha!

[VWatchie]

On 8/15/2023 at 12:28 PM, nickelsilver said:

your round and flat face punches should have- some freedom

Just to make certain I understand. So do you mean that when the punch is resting on the balance shoulder there should be a bit of freedom between the hole in the punch and the collet seat?

EDIT: Now, that didn't come out right . What I meant was:

Just to make certain I understand. So do you mean that when the punch is resting on the collet seat there should be a bit of freedom between the hole in the punch and the collet shoulder?

(@HSL drew this picture for me when I was learning)

Edited August 16, 2023 by VWatchie

[JohnR725]

I have a picture that I think will help. This is from a handout to Hamilton watch company had on doing a balance staff. so for both the punch and the base that the staff is in there is clearance.

[VWatchie]

What an excellent illustration @JohnR725. Thank you very much! 

[JohnR725]

2 hours ago, VWatchie said:

What an excellent illustration @JohnR725. Thank you very much! 

as you like the illustrations how about the entire technical document?

Hamilton technical data number 129 replacement of broken balance staffs.pdf

Edited August 16, 2023 by JohnR725

[BillM]

9 hours ago, JohnR725 said:

I have a picture that I think will help. This is from a handout to Hamilton watch company had on doing a balance staff. so for both the punch and the base that the staff is in there is clearance.

Awesome illustration, thank you. 
 

To be honest, this is exactly what I thought I had in my set up, but it’s pretty clear now that the crap I had not cleared out of the staking base plate holes was a major contributor to my failure.  
 

 

7 hours ago, JohnR725 said:

as you like the illustrations how about the entire technical document?

Hamilton technical data number 129 replacement of broken balance staffs.pdf 1.35 MB · 3 downloads

Wow, Thank you!   

[nickelsilver]

10 hours ago, VWatchie said:

Just to make certain I understand. So do you mean that when the punch is resting on the balance shoulder there should be a bit of freedom between the hole in the punch and the collet seat?

(@HSL drew this picture for me when I was learning)

Yes. But, not too much! Haha. Seriously, there should be freedom with the punch around the collet shoulder from that illustration. The collet seat is effectively the rivet, so there must be contact there.

[VWatchie]

3 hours ago, nickelsilver said:

The collet seat is effectively the rivet, so there must be contact there.

The illustration John showed illustrated it perfectly. Anyway, thanks for clarifying! 

I'll edit my post now or I'll never stop thinking about it. 

Edited August 16, 2023 by VWatchie

[VWatchie]

Here's a link to the post where I got the picture of the balance staff naming its various sections. That post, with its additional illustrations, was very useful to me at the time, and even though it doesn't add much to this particular discussion I thought it might be appreciated nevertheless. If you look closely, @HSL (where are you these days?) has indeed added a bit of space between the hole in the punch and the collet shoulder, but that was not discussed or even noticed by me at the time. So, another piece of important information gained! 

[BillM]

That like leads to a lot of topics, I didn’t find what you were referring to.