Chronotachymetre Servicing

[mwilkes]

I found a rather elegant chronograph pocket watch on the bay recently. It was listed as non-running so I took a punt on it. Not cheap, but I liked the dial. The watch wouldn't run if the chrono was engaged, and would barely run without it. It's a French watch made by LIP.

 

 

Popped the moment out of the case to have a look. It's very pretty in there...

 

Time to strip it down. Took many photos so I could put it back together in the right sequence. Here's a bird's eye view of the chronograph works

 

Removed the operating lever, pillar wheel, transmission wheel and various springs

 

Removed the chronograph bridge:

 

And the movement's now just a plain ol' pocketwatch movement:

 

Time to see what's wrong with the movement itself:

 

...and found the culprit, or at least a suspect! Cracked 3rd wheel jewel:

 

Spent a quiet Sunday morning sifting through my box of random jewels until I found one with the right diameter for the pivot:

 

Reamed a wider hole and fitted the new jewel. I was pleased the colour matched the old one:

 

Now I can put the movement back together. With the new jewel and a lot of cleaning the watch works extremely well - one or two seconds fast and only a little beat error which I'm going to ignore. Putting the chrono works back together was relatively straightforward - just a matter of lubrication and adjusting the eccentrics so that the depthing was correct:

 

Time to fit the hands. The second hand for the chrono wasn't tight enough on the arbor, so every time you re-set to 0 the hand would spin! Tightened it with a cannon pinion tightener - there must be a better way!

 

Movement goes back in the case:

 

And another fine watch for my collection of slightly-battered-but-working-well watches. This was the first chronograph I've done, so I'm extremely pleased that it's working nicely. Learned a lot in the process. One of the things I learned was not to use Naptha on dials. The astute observer will notice that the word LIP has vanished from the dial. While I feel extremely guilty for having done this to a 100-year old watch, I'm secretly delighted - the first thing my wife said when the watch arrived in the post was "lovely dial, pity it says LIP on it...", and I agreed.

 

 

Thanks for watching. 

 

[Geo]

Great job and excellent illustrations Mark!

My "Doctors" pocket chronograph has a similar dial layout, but the movement is completely different.

[cdjswiss]

Time to fit the hands. The second hand for the chrono wasn't tight enough on the arbor, so every time you re-set to 0 the hand would spin! Tightened it with a cannon pinion tightener - there must be a better way!

I do it this way - it often works.

[clockboy]

Great job Mark excellent pics.

For hand tightening I use my lathe collet but the pin vice is also a way. However and excellent job.

[autowind]

Another nice watch saved,  nice work,  well done.

[cdjswiss]

 

For hand tightening I use my lathe collet but the pin vice is also a way.

 

Of course CB! Why didn't I think of that?

[Geo]

That's the same method I use, but your idea of the pin vice is great for those that don't have lathes. :)

[clockboy]

It,s all about a really getting a controlled squeeze  it,s so easy to go to far.

[bobm12]

Good trick with the pin vise. Thanks!

[Don]

Beautiful watch and great work! Far, far beyond my current ability, but very interesting to see and read about. Thanks.

[Lawson]

Outstanding work Mark!

Always great to see the jobs people are working on, and love the pics mate

[noirrac1j]

Masteful. I don't have that skill level yet. I am building up the courage (and funds) to get a staking set. A wonderful looking watch and walk-through. Thanks.

 

JC

[frenchie]

Just saw this. Nice work. Gorgeous piece.

But being a frenchman, I have to take offense at the disappearance of the LIP brand ;)

[Geo]

I have to take offense at the disappearance of the LIP brand ;)

That's because we have had enough of your LIP Frenchie! ;)

[mwilkes]

I do feel guilty about it... Slowly I'm learning that dials need to be treated with the same respect, fear and trepidation as hairsprings.

[Mark]

Brilliant job - well done. And I really love that watch - it's a cracker.

 

Regarding the hands, I can never be bothered with doing it with a lathe collet - the pin vice is always to hand and a lot less messing around.

But you might argue that a lathe collet would compress more evenly across the length of the tube than a pin vice.

[cdjswiss]

Brilliant job - well done. And I really love that watch - it's a cracker.

 

Regarding the hands, I can never be bothered with doing it with a lathe collet - the pin vice is always to hand and a lot less messing around.

But you might argue that a lathe collet would compress more evenly across the length of the tube than a pin vice.

 

Here is yet another way of tightening a second hand that is only a little loose - with digital output!

Somewhat like canon pinion tightening.

 

[Geo]

I like your thinking Colin!

Another great use for digital calipers is removing splinters from your skin. They grip a lot better than tweezers and even let you know what size the skelf is! :)

[noirrac1j]

Geo that last suggestion is hilarious. I just had an image of me trying to pull out splinter from my foot with a digital caliper--

 

JC

[bobm12]

Both new uses of caliper noted for further use! I can combine them when a splinter gets in a watch's hand... aaaah! Just me and one of those moments!  :)

 

Great thinking guys!

 

@Colin: Good to see you around, Colin and as always with great input! Cheers!

 

Cheers,

 

Bob

[Geo]

Geo that last suggestion is hilarious. I just had an image of me trying to pull out splinter from my foot with a digital caliper--

JC

I wasn't joking Joe, they are brilliant for that. Working in engineering I was forever getting tiny slithers of metal in my fingers, and the callipers always worked when tweezers failed!

[vaguras]

Excellent wakthrough and job!!!

Congratulations!!!

Another way to evenly tighten a hand tube, is by using the appropriate size of a punch stake in your staking set. Just find the one that nearly fits the tube diameter and push the punch lightly onto the hand (no hammer needed just a finger push from the top).