Regulating Molnia/Molnija 3602. Timegrapher interrpetation help wanted

[ManSkirtBrew]

Before disassembly, the timegraph looked reasonable, but 321 degrees of amplitude was suspicious.

 

Results after cleaning, reassembly, oiling, and a slight tweak to the collet for the beat error:

 

The amplitude visually looked low, so I took a slow motion video, which looks around 150 degrees or less to me. That video is about 15 minutes after a full wind.

So far I have:

- demagnetized the movement

- checked end and side shake of the balance, which looks good to me

- checked that nothing is fouling on the balance and the hairspring looks flat

What else should I be on the lookout for when I take the movement apart again?

Edit to note that I didn't take the mainspring out of the barrel, since it looked practically new. With the low amplitude, I should do that as well. But I'd still like to find out where all the noise in the timegraph plot is coming from.

Edited October 6, 2022 by ManSkirtBrew

[nickelsilver]

Lift angle should be 42 degrees. Looks like an issue with the escapement (if you're sure the hairspring isn't rubbing somewhere). What that issue is is pretty hard to say without more investigation.

[ManSkirtBrew]

1 hour ago, nickelsilver said:

Lift angle should be 42 degrees.

Ah, thank you. For some reason I consistently forget to look that up before using the software.

And thanks for the advice. I'll start with a more thorough investigation of the pallets and escape wheel.

I did find that the mainspring was broken, so I stole a good spring from another 3602. Amplitude is still low, so while definitely an issue, not the main cause.

[JohnR725]

2 hours ago, ManSkirtBrew said:

Before disassembly, the timegraph looked reasonable, but 321 degrees of amplitude was suspicious.

it looks like half your escapement is having an issue. Then yes the amplitude is very suspicious but that's because the graphical display half of it looks bad.

your only timing in one position what if you time the watch upside down from wherever it is now or even one of the crown positions like crown down how does that look?

Then you need to check everything escapement related. It is not just the pallet stones look at those make sure they're fine but the escapement also consists of the roller jewel make sure that's in nice and tight. Also how did you lubricate the escapement?

looks like a video you have something clipped on the stem? If that's for the timing machine wouldn't you grab the movement holder and see if that changes anything.

[Nucejoe]

2 hours ago, ManSkirtBrew said:

- checked end and side shake of the balance, which looks good to me

What else should I be on the lookout for when I take the movement apart again?

 

I make a habbit of checking shakes on all arbours, with assembled movements to create end shake ( for a test)   "  loosen  bridge screws." 

What cleaning solutions did you use and how did you clean,  could you have lost shellac as you cleaned. 

 

 

[ManSkirtBrew]

48 minutes ago, JohnR725 said:

looks like a video you have something clipped on the stem? If that's for the timing machine wouldn't you grab the movement holder and see if that changes anything.

Good point. Clipping the movement holder right by the balance definitely gave me more expected results:

50 minutes ago, JohnR725 said:

the roller jewel make sure that's in nice and tight. Also how did you lubricate the escapement?

The roller jewel is clean, shiny, and tight. I also checked all the teeth and pivots on the escape wheel and pallet fork. For the escapement I put a tiny drop of Moebius 9010 on the faces of the pallet jewels and manually tick-tocked them around the escape wheel a couple times, as suggested in the training course.

 

48 minutes ago, JohnR725 said:

your only timing in one position what if you time the watch upside down from wherever it is now or even one of the crown positions like crown down how does that look?

This is likely the issue. Dial down there's something audibly rubbing. Now to hunt it down.

51 minutes ago, Nucejoe said:

I make a habbit of checking shakes on all arbours, with assembled movements to create end shake ( for a test)   "  loosen  bridge screws." 

What cleaning solutions did you use and how did you clean,  could you have lost shellac as you cleaned. 

I went back and checked everything. There's a little more end shake in the center wheel than I'd really like, but everything else seemed fine.

Right now I'm using lighter fluid only. I clean with an artist brush and pegwood, then a short run through the ultrasonic, with the parts in a small jar. I just double checked the pallets and impulse jewel, and they seem well attached, but I'll check again when I take it apart to find the rubbing in the dial down position.

Looks like the overcoil is hitting the underside of the pallet cock. If I push the stud down in the pallet cock a bit, it fixes that, but then the hairspring disc is angled and hits the balance wheel on the other side.

I guess it's more hairspring work for me. Good practice...right?

[Nucejoe]

1 hour ago, ManSkirtBrew said:

Good point. Clipping the movement holder right by the balance definitely gave me more expected results:

The roller jewel is clean, shiny, and tight. I also checked all the teeth and pivots on the escape wheel and pallet fork. For the escapement I put a tiny drop of Moebius 9010 on the faces of the pallet jewels and manually tick-tocked them around the escape wheel a couple times, as suggested in the training course.

 

This is likely the issue. Dial down there's 

Looks like the overcoil is hitting the underside of the pallet cock. If I push the stud down in the pallet cock a bit, it fixes that, but then the hairspring disc is angled and hits the balance wheel on the other side.

I guess it's more hairspring work for me. 

I think you  already have spotted the cause of the issue , since end shake seems Ok to you, only the overcoil height remains to be adjusted. if you will, post a close up picture of your overcoil, so your thread  be helpful for future refernces too. 

Regds

[ManSkirtBrew]

2 minutes ago, Nucejoe said:

if you will, post a close up picture of your overcoil

Sure thing. Here are two--same picture, different focus depth, so you can see where the overcoil is touching and where the stud is in the balance cock. Let me know if you'd like any others.

[ManSkirtBrew]

Few more for you. The place I'm at is I know how to physically manipulate the spring, but I don't know exactly the shape I'm going for.

E.g. I know the plane of the hairspring should be flat and level with the balance cock, how do I how how high off the balance cock the overcoil should be? And how far away from the plane of the main hairspring should the overcoil be?

I also know the terminal curve of the overcoil should naturally follow the arc that the regulating pins make, which you can see it's not. I assume I have to fix the plane of the spring first, then shape the terminal curve.

I feel like I saw a video on this a while back, but can't find it. There are plenty about fixing twists, bends, and bunched coils.

Any good video suggestions?

 

 

 

[nickelsilver]

You won't need to adjust the coil to hs body height, that's pretty much set when the spring is made. It looks like it will need manipulation at the stud; I can see a couple of  un-original bends there. You can work it there to bring the overcoil concentric to the regulator and adjust the tilt so that the spring is parallel to the cock. When it's true you will just have to adjust the height of the stud in the cock to get the spring at the right height (not domed up or down).

[ManSkirtBrew]

8 hours ago, nickelsilver said:

You won't need to adjust the coil to hs body height, that's pretty much set when the spring is made. It looks like it will need manipulation at the stud; I can see a couple of  un-original bends there. You can work it there to bring the overcoil concentric to the regulator and adjust the tilt so that the spring is parallel to the cock. When it's true you will just have to adjust the height of the stud in the cock to get the spring at the right height (not domed up or down).

Thank you! Also interesting, the top of the stud is cut at a fairly sharp angle to the sides, such that it doesn't sit flush with the top of the balance cock. That's something I've never seen before. It seems to be intentional, but is it just for aesthetics? I'll try to grab another photo later tonight.

[Nucejoe]

17 hours ago, ManSkirtBrew said:

 the top of the stud is cut at a fairly sharp angle to the sides, such that it doesn't sit flush with the top of the balance cock. That's something I've never seen before. It seems to be intentional

 So the stud is effectively shortened limitting height adjustment. You need a new complete balance stud.

 

 

[ManSkirtBrew]

This watch has been a great learning experience. First, the results. This is after a day of running in. I know the beat error is still a tad high, but I haven't messed with it since pressing the hairspring back onto the balance staff.

 

It turns out not only was the hairspring twisted up in a few directions, but the balance wheel itself was dished such that one edge was hitting the center wheel! A little work with my staking set was able to fix most of it. It's still slightly wobbly, but it clears the center wheel. I've been wanting truing calipers for a while--I have another of the same watch that needs a balance staff replaced, so maybe I'll use that as an excuse to buy a new tool.

I also got to use my dial foot tool, since both feet were broken on the plastic dial. It was very easy to use. The hardest part was getting the old foot out of the movement plate!

 

Only thing left is to case it up. It's got a handsome little dust cover under the snap-off back.