Straighten balance staff pivot...any guidance?

[LittleWatchShop]

Yeah, on another thread I described working on this AS XXX watch.  Got it all back together and see that one of the pivots on the balance staff is bent.

I searched the forum for answers...did not find any.

I have a copious amount of watchmaking gear...sure to have the right tool...but a tool in the hands of the ignorant is just a blunt force hammer...I appeal to the wisdom of this fine crowd!

It is a "learning" watch, so nothing invested here, but I hate to lose any challenge!!!

 

 

[LittleWatchShop]

9 minutes ago, LittleWatchShop said:

Yeah, on another thread I described working on this AS XXX watch.  Got it all back together and see that one of the pivots on the balance staff is bent.

I searched the forum for answers...did not find any.

I have a copious amount of watchmaking gear...sure to have the right tool...but a tool in the hands of the ignorant is just a blunt force hammer...I appeal to the wisdom of this fine crowd!

It is a "learning" watch, so nothing invested here, but I hate to lose any challenge!!!

 

 

Dr. Google tells me that I should just replace the staff.

[JohnR725]

I've seen people straighten the pivots if basically they're just really good and lucky. I don't remember the tweezer number but there is a blunt ended tweezer that if you warm it up not red-hot but it has to be Hot you can bend the pivot. Hot enough that you have to have insulated material like pieces of wood attached to the tweezers. But not so hot that the tweezers are glowing. This is the method I saw my instructor use in school worked really well. I've only occasionally been able to do it otherwise the pivot falls off and superglue doesn't work very well unfortunately.

Then of course there's this tool I'm attaching an image. According the text it should work perfect.

If you do know about replacing the balance staff on your watch make sure you measure it ahead of time because? Well for instance you can look in the bestfit book and figure out which staff it's supposed to be and compare with your measurements just to make sure to avoid unpleasant surprises like getting the wrong staff.

[LittleWatchShop]

1 hour ago, JohnR725 said:

basically they're just really good and lucky

I was able to "improve" the situation using a balance wheel poising tool to see which way I need to adjust and then just giving a little torque here and there.  I am not trying to fix a watch for a customer--just fooling around trying to improve my skills on a learner movement.  I got lucky!

Edited February 15, 2021 by LittleWatchShop

[Graziano]

2 hours ago, LittleWatchShop said:

Dr. Google tells me that I should just replace the staff.

They are easily replaced 9 usd ebay 

Edited February 15, 2021 by Graziano

[mikepilk]

I've never managed to straighten a pivot more than a tiny amount - anything more and they've all broken.

A chance to practice replacing balance staffs ! 

[nickelsilver]

The tweezer John spoke of is Dumont #8, they are specifically for straightening pivots. As he said, you want to heat them up in an alcohol flame. I hold the part in the lathe, heat the tweezers until they are just barely able to be held, rotate the part slowly by hand and coax the pivot back. They do leave marks as they are steel, I sometimes use very blunt nickel tweezers to avoid that. Or figure I'll give it a lick in the Jacot tool. If the pivot isn't severely bent it works maybe 60% of the time (if it's just slightly bent it pretty much always works). I don't really like the Seitz jeweled straightening tool for straightening- the heat really helps and you don't have it there. But that tool is fantastic as a gage, as the jewels are stepped by 0.0025mm increments.

 

One thing on the Seitz tool- if you get one, don't clean it in a normal cleaning solution. I know a guy who ran his through the machine and whatever metal it's made from reacted strangely and all the jewels fell out!

[praezis]

10 hours ago, JohnR725 said:

Then of course there's this tool I'm attaching an image. According the text it should work perfect.

They call it "pivot breaker" in Switzerland - I was told.

I only use it to test pivots if there is doubt if straight or not.

Frank

[AshF]

Still made, and quite cheap too....

https://www.cousinsuk.com/product/balance-staff-pivot-straightening-tool

[LittleWatchShop]

2 hours ago, mikepilk said:

A chance to practice replacing balance staffs ! 

I have an Apollo 7J timer that needs a new staff.  It will be my "staff" project once I find one. 

[LittleWatchShop]

1 hour ago, nickelsilver said:

The tweezer John spoke of is Dumont #8, they are specifically for straightening pivots.

Ahaaa!  Been wondering what the purpose might be for this tool.  Mine does not have a label, but it looks like the images on the web.

[rodabod]

One thing to bear in mind is the increased likelihood of the pivot breaking after the fatigue and work-hardening. 

[nickelsilver]

31 minutes ago, rodabod said:

One thing to bear in mind is the increased likelihood of the pivot breaking after the fatigue and work-hardening. 

This is true. When I do straighten one, when it's running nice and true in the lathe, I'll push on it to test. Every now and then one just crumbles off. Also a reason if it's bent like 45 degrees (it does happen), I won't even try. If somehow it does straighten and doesn't break then it was too soft to start with.

[WellAdjusted]

For what it's worth, a "clock guy" once told me he would mount the balance in a lathe, heat the tip, and then place a staking set punch over the bent tip. Spinning the staff inside the punch would nudge it closer to true. He would step down to smaller and smaller punch hole sizes. It sounds odd, but it worked for me once. I would imagine the heat and hardening are a flaw in this method.

Bent pivots are incredibly fickle. Sometimes a horribly bent pivot straightens easily; other times, a slightly bent pivot snaps off when you look at it wrong.

[Bauertime]

I've wondered why they couldn't make a set of different sized sleeves or tubes with a point on the end that you just slide or glue on, instead of replacing the whole staff.

[JohnR725]

1 hour ago, Bauertime said:

instead of replacing the whole staff.

The catch here is in modern watch repair if the staff is available changing it is really fast and relatively easy to do. Like for instance at this link a nice video

https://youtu.be/vIQvAm4GC5U

But if you look in the watch repair books they do tell how to Re-pivot staffs. Although most people are more likely to Re-pivot a wheel because they're harder to get. Then another video

https://youtu.be/brKlhDe1KxE

Then I have this really weird feeling I've seen something like you describe but just can't quite remember where?

[AshF]

I recently stumbled across this video of a repivoting a wheel.  This guy uses a really nice tool for it, makes it look easy.

 

 

[Nucejoe]

On 2/15/2021 at 10:01 PM, WellAdjusted said:

For what it's worth, a "clock guy" once told me he would mount the balance in a lathe, heat the tip, and then place a staking set punch over the bent tip. Spinning the staff inside the punch would nudge it closer to true. He would step down to smaller and smaller punch hole sizes. It sounds odd, but it worked for me once. I would imagine the heat and hardening are a flaw in this method.

Bent pivots are incredibly fickle. Sometimes a horribly bent pivot straightens easily; other times, a slightly bent pivot snaps off when you look at it wrong.

Sounds good and well worth trying to master it.

Thanks for sharring.

[LittleWatchShop]

2 hours ago, AshF said:

I recently stumbled across this video of a repivoting a wheel.  This guy uses a really nice tool for it, makes it look easy.

 

 

I have this tool (for the most part).  Several years ago when I was contemplating selling all of my Dad's stuff, this was first on the list to sell.  I changed my mind...glad I did.

[praezis]

I have the tool (from the video) in different variants but don't use it. I wonder if anyone else does (except for YT videos). You do not see, what happens, if you drill or just polish, how deep you are, if chips are coming etc.

I rely on my lathe, no issue esp. with 'big' drills like 0.3 mm 

Frank

Edited February 19, 2021 by praezis

[JohnR725]

3 hours ago, praezis said:

I have the tool (from the video) in different variants but don't use it. I wonder if anyone else does (except for YT videos).

I'm reasonably sure the tool has been discussed in this group somewhere. Plus similar tools for the same purpose. Then I know there's a couple of additional videos on YouTube like this one.

https://youtu.be/FBZWZfbxeJw

[AshF]

What I believe you have there @LittleWatchShop is a Jacot tool and not a pivot drilling tool.  Unless you can use a Jacot to drill pivots?

[LittleWatchShop]

7 minutes ago, AshF said:

What I believe you have there @LittleWatchShop is a Jacot tool and not a pivot drilling tool.  Unless you can use a Jacot to drill pivots?

I think you are right...I was not paying close attention to the configuration.

[LittleWatchShop]

Here is JD using the tool I have.

[JohnR725]

19 minutes ago, AshF said:

Jacot tool

I suspect now that you have the name if you do a search we've covered this tool before. Then the unfortunate problem with this tool is it takes a lot of practice to get really really good. But if you're really really good it produces a super nice finish on Pivots.