Impulse jewel on balance staff

[signcarver]

I need help troubleshooting a balance complete.

I replaced the balance staff, because the top pivot of the original was broken. This is my first attempt at doing this. Now the watch won't run. The balance oscillates for a few ticks but then stops.

When i replaced the roller table, although i tried, i did not get the impulse jewel aligned with the mark for the original position (see picture below).

Is this enough to cause the balance not to oscillate? Or what ramifications might it have?

Thank you for your help!

[nickelsilver]

Pull the roller table and put it back where it should be. The position of the hairspring is (very) important too, there is often a little "pip" on the balance rim marking where the stud should line up. When in the watch, no power, the roller jewel should be in the fork slot, and the fork should be midway between the bankings.

[JohnR725]

1 hour ago, signcarver said:

Is this enough to cause the balance not to oscillate? Or what ramifications might it have?

the ramifications of putting the roller jewel in the wrong location is the watch will not be in beat and it will never run.

1 hour ago, nickelsilver said:

When in the watch, no power, the roller jewel should be in the fork slot, and the fork should be midway between the bankings.

one of things you should always check on a watch especially after replacing the balance staff is to verify that the watch visually is in beat. The above quote is telling you that and I'm attaching a picture so you can visually see what it should look like.

 

[Nucejoe]

 From the picture the stud holder is mobile, it alao is a beat adjustor arm, move it to bring the oscilator in-beat, thats impulse be in midpoint of ........ as said above.

In case that didn't do, then impulse jewel must have been positioned  nowhere close to in- beat position, so needs repositioning. 

 

[nevenbekriev]

Something to add:

The angle marked on the drawing should be always 90 degr. It is not important for the movement, as it will work regardless what the angle is, but it is important for the watcmakers that will service the watch. The balance arm forms certain figures when the balance rotates. This figures are symmetrical and in case the angle is exactly 90 degr. and the movement is 'in beat', then the axe of symmetry coincides with the line of bearings balance-lever (the vertical axe on the drawing). So, a watcmaker will be able to say if the watch is exactly in beat just by a look at the oscillating balance, and no timegrapher or other device will be needed.

Edited March 10 by nevenbekriev

[signcarver]

Thank you all! I will follow your instructions and report back.

 

[signcarver]

Dammit Jim! 

Take 2: So i thought on my first attempt i had carefully aligned the impulse jewell properly. However, the pictures above show that not to be the case.

This time i was extra careful to be sure i aligned the impulse jewel correctly. And i did. 

However, after installing the hairspring / collet, the impulse jewel had move about 45 degrees. So something i did in installing the hairspring / collet caused the roller table to move.

Take 3: coming up...

[JohnR725]

On 3/10/2024 at 9:16 AM, signcarver said:

I replaced the balance staff

 

6 hours ago, signcarver said:

However, after installing the hairspring / collet, the impulse jewel had move about 45 degrees. So something i did in installing the hairspring / collet caused the roller table to move.

 when replacing balance staffs you have to make sure that the balance staff is properly riveted and doesn't have the ability to rotate. if your balance staff is able to rotate then everything else on the balance staff will also rotate depending upon how poorly the rivet is.

[nevenbekriev]

Yes, the balance staff rotates with the collet and the roller position changes. And whole truing and poising too.

Edited March 12 by nevenbekriev

[signcarver]

@JohnR725 I would bet my rivet is defective. I was very careful when installing the collet. I used my staking set and gently pushed the collet on with my finger, no hammering. Thank you. Can i attempt to fix the rivet or must i get a new balance staff?

@nevenbekriev I did poise the balance using a 3 legged watch poising tool. Thank you for the reminder.

 

[nevenbekriev]

You should remove the roller and continue riveting the staff. Use pin wice to  hold the staff where the hairspring seat and test if the rim can be easuly turned.

[signcarver]

3 hours ago, nevenbekriev said:

You should remove the roller and continue riveting the staff. Use pin wice to  hold the staff where the hairspring seat and test if the rim can be easuly turned.

@nevenbekriev Great idea. I will do that! Thank you!

[JohnR725]

5 hours ago, nevenbekriev said:

Use pin vice to  hold the staff where the hairspring seat and test if the rim can be easuly turned.

their minor variations to this. Like for instance take a tiny piece of Rodico on the pivot of the staff hold the balance wheel an attempt to rotate the staff with your pin vice the pin vice is supposed to slip because yes the rivet really does have to be very secure if it rotates you'll see whatever you stuck on the end rotate.

[signcarver]

Take three... 

I disassembled the balance and did a few more taps on the rivet and made sure it was solid. I reinstalled the roller table, this time with the impulse jewel in the proper position, per instructions above.

Now the watch only runs in the dial up position with the balance cock not completely screwed down tight. So something is binding but i can't figure out what. in inspected the top and bottom balance jewels and they seem fine.

The new balance staff was "correct" for the movement but as you can see, the top part is slightly different from the original. (The top pivot was broken on the old one (left))

I'm investigating the hairspring and will post pictures soon. The hairspring seems to be rubbing the timing pins at the bottom.

Thank you!

Edited March 21 by signcarver
spelling corrections

[RichardHarris123]

I'm assuming inadequate end shake, have you tested for it? 

[signcarver]

@RichardHarris123 Checking... Thank you!

[Nucejoe]

42 minutes ago, signcarver said:

Should i try to shorten one of the pivots? (which one, if so how - what tools?)

Only if roller table isn't and can't be  otherwise leveled with escape teeth, and you can't move settings.

35 minutes ago, RichardHarris123 said:

I'm assuming inadequate end shake, have you tested for it? 

Inadequate end shake might at worst reduce amplitude.

Zero end shake would stop the balance dead.

42 minutes ago, signcarver said:

Now the watch will only run in the dial up position with the balance cock not completely screwed down tight. So something is binding.

In general this  indicates faulty jewels or short or faulty pivot on cock side, exclude short pivot in your case, as it doesn't seem to be a problem here.

How to fix,

Shim the cock, whilst other engagement in escapement are good. 

Good luck.

Edited March 21 by Nucejoe

[JohnR725]

50 minutes ago, signcarver said:

Now the watch only runs in the dial up position with the balance cock not completely screwed down tight. So something is binding but i can't figure out what. in inspected the top and bottom balance jewels and they seem fine.

The new balance staff was "correct" for the movement but as you can see, the top part is slightly different from the original. (The top pivot was broken on the old one (left))

I'm investigating the hairspring and will post pictures soon. The hairspring seems to be rubbing the timing pins at the bottom.

one of the minor problems with balance staffs quite common with American pocket watches is pivots sizes can be different it's usually in the specification of the balance staff. American pocket watch staffs get a complicated enough that one part number like for a particular Elgin watch could refer to 12 different staffs all uniquely different. Basically I think there's three or four groups of whether it's a new style or old-style and then all the rest of the variations are pivots size.

Then of course you did you check the jewels to make sure they're not cracked often times they get cracked or shattered when the staff breaks.

The other thing that sometimes happens our staffs are deliberately made oversize and the watchmaker is supposed to fit the staff to the watch. In other words your pivots could be too long and you might have to reduce them slightly. A lot of this depends upon when the watch was made of is a much newer watch the staff should fit perfectly but a vintage may require some fitting of the staff.

Then hairspring rubbing is quite common especially when you're learning watch repair and it's amazing what that can do to keeping a watch from running can lose all your amplitude right there. Which is why one of the things you do what restaffing a watch is before even put the hairspring on his put the balance wheel in without the roller table and see how it fits see if it spins as now it's a perfect time to make adjustments. in other words it's usually best to go one step at a time rather than all or nothing and then wonder what the problem is.

[Nucejoe]

How can this be

4 hours ago, signcarver said:

The new balance staff was "correct" for the movement

 

3 hours ago, signcarver said:

 but as you can see, the top part is slightly different from the original. 

I see the difference without  . 

Cutting a long pivot is easier said than done, not to mention the need to polish the pivot end. 

You might get by with just shimming the cock.

Rgds

 

[signcarver]

@Nucejoe @JohnR725 Thank you - so much good information and things to try.

Thank you again for your continued help.

One thing i noticed after i posted was that, again, the roller table had moved. So my second attempt at riveting the balance staff must have broken loose. I may not have had the correct size stakes to disperse enough metal on the rivet? I did check it after i riveted and it seemed solid but there wasn't much metal overlapping the balance wheel. Note that the roller table didn't move right away because the balance did oscillate properly when the watch was dial up AND the balance cock wasn't fully tight.

Anyway, now i am going to order a new balance staff and go thru a check list of your suggestions and try again, paying extra attention to the riveting process!

I did inspect the jewels and they weren't cracked. However, there does seem to be a lot of play (sideways) in the top jewel looking thru the microscope when the balance is oscillating.

 

[nevenbekriev]

You first need to read all this thread

You need to understand, that every time You punch the staff out, the hole in the balance arm gets bigger, thus the chance that You will be able to rivet the new staff gets smaller.

Edited March 22 by nevenbekriev

[Nucejoe]

On 3/21/2024 at 9:25 PM, signcarver said:

Now the watch only runs in the dial up position with the balance cock not completely screwed down tight. So something is binding but i can't figure out what. 

I am guessing the roller table is at the wrong height, so in dial down position rubs on the fork horns because it has move down  by gravity, in dial up position roller table  moves away from the horns, thus doesn't rub and can works .

Are you set up to show  a side view of the roller table and fork , in DU & DD poistions?  

Edited March 22 by Nucejoe

[signcarver]

19 hours ago, Nucejoe said:

Are you set up to show  a side view of the roller table and fork , in DU & DD poistions?  

@Nucejoe Sorry, no. I took the balance staff apart.

22 hours ago, nevenbekriev said:

You first need to read all this thread

You need to understand, that every time You punch the staff out, the hole in the balance arm gets bigger, thus the chance that You will be able to rivet the new staff gets smaller.

@nevenbekriev Thank you! I wonder even if i buy a new balance staff it will work? perhaps i'll have to buy a balance complete if i can find one. The watch was a donor for another project and i knew the upper balance pivot was broken but i wanted to try my hand at repairing it.

[nevenbekriev]

For sure there will be no beter chance to rivet a new staff there if You did not suceed wit the first one. Thinking that the pnches are not propper and the problem is there is misconception. If the hole is too big, then no riveting will be possible. Bit I actually don't know how big the hole really is. In the normal case, the staff should fit tight in the hole, some force will be needed to push it in place. If there is just a small free play, riveting is possible, but some danger of eccentric rotation of the balance exists. This means trueing, poising and timming problems.  If the hole is really big, then the only reasonable way is making of custom balance staff. Some compromise moves exist, like soldering of the staff in place with led solder. The led is good enough way to fix the staff in place and it is easy to remove it when needed.

[JohnR725]

On 3/22/2024 at 11:20 AM, nevenbekriev said:

You need to understand, that every time You punch the staff out, the hole in the balance arm gets bigger, thus the chance that You will be able to rivet the new staff gets smaller.

just so everyone understands that is not universally true statement it depends on the balance itself and whether the staff was designed to be punched out there other factors here.

38 minutes ago, nevenbekriev said:

like soldering of the staff in place with led solder.

that this would be interesting procedure that I don't recall ever reading about in any book?

 

why don't we go back to the beginning sometimes reviewing things helps? For instance I don't recall ever seeing the watch model number which watch is this your getting a balance staff for anyway?

Then it's always good to measure the old staff preferably with a micrometer then measured the new staff to verify that all dimensions are exactly the same did you do this?

then the balance staff does it have a part number and where did you purchase it from?