Tricky vertical amplitude problem

[margolisd]

Hi guys. Here's a tricky one. I'm working on an old Election 645 movement from the 30s. After quite a bit of work I'm getting around 268 amplitude in both the horizontal positions. But, here's the thing, the amplitude plummets to around 155 in all the vertical positions. I think the poise is quite good because all the vertical positions are consistently around 155.

I've done everything I can think of...

• Fully cleaned
• New mainspring
• Tested side and end shake of every single wheel. They all spin really nicely and totally flat. Every wheel spins freely in its pivots when tested with the bellows.
• Polished every single pivot
• Tested the arbour is totally free in the barrel. It is.
• Burnished the pallet fork
• Balance spring is nicely centred, clean and running flat. Terminal curve is correct.
• Lubricated pallet stones.
• Tested the pallet fork including run to banking which is okay.
• Static poised
• Carefully oiled everything with correct oils.
• Demagnetised and tested for magnetism multiple times.
• Studied every single jewel under the microscope for crud / cracks. They are totally clean and smooth.

The only thing I can think of is that the balance wheel (which is transplanted from another Election 645) is just too heavy. But before I go in and file bits off, I wanted to get your expert opinions. What did I miss?

Thanks all!

[HSL]

You seem to have done an impressive amount of work. If it like you say works perfect in both horisontal positions it would show everything looks fine in the drive train this far. 
The thing with placing the movement vertically is the dramatic increase of area the pivots can create friction through. But since it is a consistent increase in every position I would rule everything except the balance out as the culprit. 
You also have come to the same conclusion. I'm not sure the balance wheel is the only culprit maybe the hairspring just lost its swung, just like the mainspring  it's made of metal and will suffer from metal fatigue, the increased friction lying vertical will in such case make the amplitude go down. Just a thought.

[margolisd]

Thank you for the advice. Do you think removing weight from the balance will help? Or will this just speed up the watch?

I was also thinking of locating slimmer jewels?

It's not a very valuable watch. But I'm determined to fix it. It's got personal...

 

[nickelsilver]

You said you checked the escapement, how much drop and total lock do you have? Heavy lock is exacerbated in vertical. Also, you transplanted a balance- if the pivots are slightly large they can be totally free (thus the decent horizontal amp) but make too much contact in vertical. If the balance endshake is a little too much the pivots can end up almost out of the hole jewels in vertical and be resting on the olived area increasing friction. And, on some cheaper movements the hole jewels aren't olived. They may even be convex but the hole isn't olived.

 

Finally, some movements are just poorly proportioned and you see a 100ish degree amplitude drop in vertical. If you've exhausted all options and the watch has to "perform", the only option is a slightly stronger mainspring and flattening the pivots to drop the horizontal amplitude.

 

 

[HSL]

Like with everything reducing weight on the balance wheel will make it easier to turn but it will be less energy stored, changing the hairspring to a fresh one would  be no: 1 thing I would do  if everything else is fine.
I'm not a huge Rolex fan but have to give them a credit for their approach to make the hairspring to live slightly longer.
http://static.rolex.com/flipboard/the-parachrom-hairspring.html

Nickelsilver has a couple of god points with the size of the balance wheel.

[nickelsilver]

If the hairspring had changed in strength the rate would be wildly out of range. Reducing weight of the balance in any meaningful way would require a custom hairspring.

Hairsprings work in a range of movement that doesn't come close to creating any metal fatigue.

[margolisd]

Okay thanks guys. You have given me lots to think about.

The side shake is perceptible. I do have a Jacot Tool and could make the pivots thinner. Do I risk it? How much side shake before I just create a new problem?

[saswatch88]

1 hour ago, nickelsilver said:

You said you checked the escapement, how much drop and total lock do you have? Heavy lock is exacerbated in vertical. Also, you transplanted a balance- if the pivots are slightly large they can be totally free (thus the decent horizontal amp) but make too much contact in vertical. If the balance endshake is a little too much the pivots can end up almost out of the hole jewels in vertical and be resting on the olived area increasing friction. And, on some cheaper movements the hole jewels aren't olived. They may even be convex but the hole isn't olived.

 

Finally, some movements are just poorly proportioned and you see a 100ish degree amplitude drop in vertical. If you've exhausted all options and the watch has to "perform", the only option is a slightly stronger mainspring and flattening the pivots to drop the horizontal amplitude.

 

 

just a thought i am not familiar with this movement but dont swiss movements have rounded pivots? or is that only for the older movements. i think swiss adopted the flat pivots from the american movements at some point but not sure when. i work on vintage swiss trench watches and i know over time the pivots get flattened due to dirty oil grinding the pivot head down creating a lot of friction and i usually have to round it off on a pivot polisher with diamantine powder. 

OP:

-if you polished the balance pivots how did you do so?

-also did you set the watch in beat? did you get any beat error on the timegrapher? i did not see that you did that on your list, especially since this balance came from a different movement the hairspring or roller jewel may not be positioned properly causing issues on the drop/lock in vertical. when balance comes to a rest the roller jewel shout sit right in the middle of the banking pins.

-new hairspring maybe in order there is always extra stress on the BW in vertical. what kind of oil did you use on the escape and and Balance.

[margolisd]

It does have rounded pivots and they're in good shape.

I polished the pivots on my Jacot Tool. I just use pegwood with some jeweler's rouge and a little clock oil. They were already pretty good to be honest.

Yes, the watch is in beat to within 0.5 ms.

I use 9010 on the escapement and 9415 on the fork jewels.

 

 

[saswatch88]

2 minutes ago, margolisd said:

It does have rounded pivots and they're in good shape.

I polished the pivots on my Jacot Tool. I just use pegwood with some jeweler's rouge and a little clock oil. They were already pretty good to be honest.

Yes, the watch is in beat to within 0.5 ms.

I use 9010 on the escapement and 9415 on the fork jewels.

 

 

ok cool! what about setting watch in beat? its not way off but you should get a 0 beat error if its perfectly in beat. it may help.

[margolisd]

It's tricky. There is no beat regulator!  I have to turn the collet. Quite a lot of trial and error!

[nickelsilver]

The sideshake on the balance pivots is something that's not very well addressed in texts. It's proportional to the diameter, that's for sure. I do a lot of old lecoultre movements for one of the big brands, and the pivots are often between 0.06mm to 0.07 (thig big ones, yay!). The 0.6 pivots would be in a jewel that measures 0.65 as an example.

I had an AS 1012 a couple of years ago, for a friend, similar problem, took it on as a learning project. Turns out the hole jewels were straight holed. Changed to olive, no difference. Did same for pallet hole jewels, no change. Reduced pivots, same. Made new staff, from 0.002 microns sideshake to 0.01 no change. Escapement was pushed to absolute limit. I have a bunch of these movements and switched and swapped stuff and it was the same. AS made some great stuff and I'm a fan but conxlusion was this one was a dud. There are probably some 1012s running great out there but after probably 30 hours of work this one left with a slightly reduced power reserve and flat pivots.

To trenchdude, the swiss never adopted flat pivots with some rare exceptions.

[saswatch88]

14 minutes ago, margolisd said:

It's tricky. There is no beat regulator!  I have to turn the collet. Quite a lot of trial and error!

well do this take out pallet and cock and see where roller rests. what i do is remove hairspring from BW and cock. instal BW and cock in movement. line up roller jewel. place spring on top off cock and line up stud with the hole. then while holding the BW from the side with your finger tip in the exact center position. mark the location of the HS stud on the balance wheel, wax pencil or thin marker, then reinstall the HS on the BW and cock, then reinstall complete balance. i never liked using a collet wrench, pivots and springs can get damaged since there is alot more trial and error, my way is a little more involved but if done right its a one time deal, and the HS and pivots are safe from destruction.

edit: make HS when placed on top of the cock is in the correct position, the collet side with the beveled edge should face down to the balance, this is the way it should be installed on the BW.

Edited March 23, 2019 by saswatch88

[Nucejoe]

Bent pivot?  

 

[Nucejoe]

Please ignore my post as only two words at end got printed, I have no idea where the rest of my post is, perhaps the dog got it.

 

[rodabod]

I often observe the balance wheel oscillating without the pallets to get an idea of freedom of movement. You could try the same and compare vertical with horizontal. Helps to take the escapement out of the equation.