"Chronometre" with Nachtigall movement pocket watch repair

[szbalogh]

Once disassembled it turned out having many issues not just the broken balance which was mentioned by the seller.

1. Identification: The nachtigall stamp on the 3/4 plate is obvious, but what is that arrow logo under the barrel bridge? Is it a G or 9 or e? Nothing similar on Microlisk for pfeil (arrow) or G. And there are '36' marks under the dial and the 3/4 plate. Maybe serial number?

2. Error list: Broken balance, ok maybe can make new one. Broken 3rd wheel pinion, ok maybe can repivot this. But how to repair broken and bent center wheel? I think that the previous "watchmaker" had issues removing the cannon pinion since even i cant do that, there is nothing where i can grab it. How can i remove the cannon pinion?

And there are some minor issues like the missing swan neck, no dial feet, broken set lever and one broken screw...

3. Look at this lever. It has no pallets and it is pised(?). It is riveted, maybe i can change it to a palleted one?

 

[Marc]

The symbol is an arrow stuck through an apple, which I  have a feeling is FHF but I could be wrong on that.  I have no reference material here at work but will check when I get home. 

As for the pallet stones, look at the pallet side on. A lot of old pocket watch pallets retained the stones between a plate top and bottom, rather than either side.  The stones may also be colourless so more difficult to see.

[szbalogh]

10 minutes ago, Marc said:

The symbol is an arrow stuck through an apple, which I  have a feeling is FHF but I could be wrong on that.  I have no reference material here at work but will check when I get home. 

As for the pallet stones, look at the pallet side on. A lot of old pocket watch pallets retained the stones between a plate top and bottom, rather than either side.  The stones may also be colourless so more difficult to see.

Thank You! Thats it, FHF, Fabrique d'Horlogerie de Fontainemelon SA

I have the feeling that those two steel levers are the "pallets". At least i hpe so, since i dont have to repair the lever as well

[szbalogh]

Finally the cannon pinion was wrapped in 2 layers of soft red copper and pulled off with plyers. 

One problem solved, three other discovered after cleaning the mainplate. Balance and 3rd wheel jewels are cracked. 4th wheel just chipped off a bit but will do. One dial retaining screw simply dont have threads just a tapered and and was pushed in his hole. 

A friend of mine who has a batch of ~200 jewels will search proper pieces for cheap. The jewels are wrapped in the baseplate metal, now i have to make that hole opener and closer tool. 

[bobm12]

That's quite a challenge, SZ! And a great project, you have my full attention!!!!

Cheers,

Bob

[szbalogh]

Just a quick report. 3rd wheel drilled with 0.4mm carbide microdrill. The other pinion is ~0.2mm and the book said the hole should be 1.5x the final pinion diameter but my 0.3mm bit is broken. The depth its around and should be 2x the diameter. 

The process was not straightforward. The 0.4mm drill burnished the hole (maybe the staff is too hard, although i tried to anneal it in a gas lighter flame, see the color of the staff), so the hole was predrilled with the 0.2mm drill and then reamed with thw 0.4 drill. 

Next i will try to drill the balance. The healthy pinion is around 0.15mm, but i can choose the broken one since the jewel on that end is broken. By the way, the jewels from my friend will arrive tomorrow. Now its time to make the jewel setting closing tool

Edited June 14, 2016 by szbalogh

[szbalogh]

Just a quick report about my first jeweling adventure. 

Recieved a lot of jewels from my friend but it turned out most of them are for wristwatches. There was however one that seemed ok in diameter for the 3rd wheel pinion. The hole was 0.1mm and the pinion is 0.27mm so tooled up for jewel hole drilling  I was asking Steffen Pahlow for the proper method.

First, 0.2mm brass stick tapered to 0.27mm was turned in the Dremel from 0.7mm wire. The jewel was hotglued first on a turned tootpick mounted in the Dremel, later on 2mm brass wire. The jewel was centered while holding the lighter near the glue and turning with brass tweezer toothpick. 

The brass stick was dipped in polishing paste and simply pushed against the jewel hole while turned in the Dremel with around 5000-1000 rpm. It was really slow when i realized that i was using the finest paste  After changing to coa rse one it was quick. 

Almost through.

At this point the jewel still sticked to the pinion bottom. After polishing the hole with fine paste it was moving freely on the pinion. 

Now it was time to mount the jewel into the movement plate. It turned out that the jewel is not for such a setting. It is a friction fit jewel. So several modifications were made to the jewel. The flat bottom had to be tapered a bit taht i can rub the brass setting over the edge. Moreower, the thickness, and diameter had to be reduced a bit.

Have no pictures from all steps but made a shematic picture showing all modification steps.

Reducing external diamater. 3mm soft steel nail was reduced to 1.4mm. The jewel is 1.5mm. 0.8mm hole was drilled in the reduced end where the jewel hole drill bit was hotglued. The jewel was simply pulled over the brass stick and glued and centered as mentioned above. 

Another 2mm brass wire was drilled to 1.5mm and added some co**BLEEP** (5000grit) polishing paste on the jewels and the brass tube was pulled over the jewel. The tube was moved back and forth while the jewel was turned 5000-10000 rpm. Diameter was reduced to 1.38mm. 

After altering the jewel it was perfectly fit in the setting. A setting closing tool was made (according to the setting opening tool in my earlier post) but it turned out that a simple female cone end-drilled steel wire is perfect for closing the setting. 

The gear staff is vertical with a small degrees of free tilt. 

 

Edited June 19, 2016 by szbalogh

[Geo]

Truly excellent, I' almost speechless!

[szbalogh]

1 minute ago, Geo said:

Truly excellent, I' almost speechless!

Thank You, but lets see what happend to the endshake. 

[jdrichard]

Amazing work

Sent from my iPhone using Tapatalk

[szbalogh]

The story continues. One more error discovered. 

After finishing the repivoted staff and trying the gear in place and in the train i deiscovered huge endshake.

Repivoted staff before polished to size. 

It was not affecting the train which was moving freely, but i was suspicious since this movement tend to be "not the worst quality" considering the nice finish. The problem was, that the middle of the train bridge was bent upwards. The bridge however was flat if not mounted on the baseplate. Notice on the picture the two red lines showing that the streight steel piece is not parallel with the whole plate. Moreover, the bridge plate has an angle to the baseplate (red oval).

Looking on the next picture one can understand this behaviour. The two halves of the train bridge is only held togehter by those two thin parts marked with red.

So the not precisely inserted alignment pins coused the bending of the bridge plate.Yes, the plate had to be forced in place, but one wouldnt think that this relatively small force could bend it.

The problem was solved by increasing the diameter of one of the alignment holes (marked with red) in the baseplate. In particular, from 0.95mm to 1.1mm. One would think that this is a bad layout for a bridge plate. What are Your thoughts abot this?

 

[szbalogh]

Now lets drill the balance! The healthy pinion is 0.1mm. The other i am drilling to 0.2mm. 

The left female cone has a 0.2mm deep hole and shoulders made with 0.4mm drill. The right one has special shape to align the drill and the balance perfectly centered (see my pivot drill post). I have made a picture of the hole but it cant be seen even through the loupe. Will investigate it with the microscope tonight. 

[szbalogh]

ANother great find in the movement. After grinding another impulse jewel ...

... and trying to true the balance in the movement i have noticed random sideshake. The balance cock hole jewel was not secured. Looking on it closer its obvious that it was replaced improperly. It seems to me that the material is just hammered over the jewel. Not to mention that the hole is way to big for the pinion. 

I could find a jewel close the desired one in the lot bought from Redrooster. Not secured yet, just mounted to check the balance. The hole is a bit tight but will check again after polishing the pinion which also need some care. 

Oldhippy: i hope the music is of Your taste

 

 

[Michael]

Hi SZ, great news that you have found more problems, as it will mean more posts from you, and I find it amazing how you work on these tiny parts with such skill (and are able to take pictures and videos). I really don't know how you can do it so well. Anyway, as soon as I have time my next project is to copy your pivot drilling machine, as I want to get any questions to you before you have your Patent on it!

[szbalogh]

3 minutes ago, Michael said:

... Patent on it!

Sweet  Feel free, I have also copied it. By the way. I am about to add a balance truing extension to the tool. Just need another bearing rod and add the pointer pin. As i can see most of these calippers are handheld, thus the pinions getting pressure according how tight the user is holding it. This one however is spring loaded which seems much safer. I think that only one spring is enough at either side. 

[szbalogh]

So much better

 

Edited August 11, 2016 by szbalogh

[Cad101]

Nice and true is that excellent 

[szbalogh]

Now that the movement coming slowly to live again i am started looking on the dial came with the watch. It is definately not the original, since it is smaller and the hole for the hands wheels are to big. I think that a watch that gave me so much experience should be matched with a custom dial, with a custom enamel dial. 

[szbalogh]

While browsing on the bay i have found similar movements and one had the same sized minute wheel like i needed. Two movements for parts were bought and arrived today. The minute arbor is of different size but the wheel seems ok. Popped it from the arbor and i noticed, that the new wheel has thinner internal diameter, so i could file down the arbor teeth to a coned shabe and reamed the gear hole a bit. Staked to place and it transmitting flowlessly (without real spring force just tried with a tootpick).

The old broken gear was 13,20mm and the new one is 13,18mm. I hope that those 1/100 mm shorter teeth wont make any difference. What do You think?

My other concern is that the old gear seems much stronger. It is 0,34mm thick and has much wider spokes, while the new one is 0,28mm thick. 

I just need to tighten the gear with a hollow stake by hammering the gear or with a domed hole punch by hammering the center wheel teeth ends. Which would You suggest? Or shouls i do both to secure the gear?

Yepp, thats my improvised staking bench... with only one hole (1,4mm) yet

 

Edited August 31, 2016 by szbalogh

[szbalogh]

The movement is ticking but with ~100 degrees amplitude. Beat error is low. Hairspring looking good. The impulse jewel may be wrong... Actually, the movement bought for replacement has also an Ellipsenstein. I will replace that and see what happens. 

Also its looking like the center wheel staff is not upright. 

First the replacement center wheel was looking like an umbrella after riveted to the staff. The watch was stopping randomly as the center wheel was touching the balance wheel. This was corrected.

[szbalogh]

Bang... lost the replasemnet impulse jewel... Left it out at night on the bench to continue in the morning. And then i forgot it.... arghhh...

Noticed however, that the grnded jewel is tilted in two directions. Corrected this and now it has between 120 and 150 degrees amplitude. Surprisingly, the amplitude drop and rate change in vertical positions is low. I think i like Breguet hairsprings

[szbalogh]

An update to this repair.

Had no time and tools to make a new swan neck regulator, but acquired one similar and working movement which had one.

Luckily it was interchangeable and fitting to the Nachtigall. 

The movement is running since my last post. Made some hairspring adjustment and the amplitude increased from around 100-150 up to the 250-150 range. 

There is still a problem which i have noticed only yesterday. The balance bridge cap jewel is wobbling and making the amplitude irregular.