Jaeger LeCoultre A-10 chronoflite aircraft clock

[bamadadof3]

I’m looking for information on a clock I bought it is a Jaeger chronoflite A10. Does anyone know if there is an actual caliber # for this clock? If looked everywhere and can’t find anything other than the A10 number. I almost have this clock running but messed up and broke a shaft on a very important drive cog and it will take a lathe to repair it. I would love to find a parts blow-up of this fantastic clock. I have looked at several really good websites dedicated strictly to these types of clocks but actual technical info seems to be missing and I really don’t want to spend $20 for a book that may or may not have the info in it I want.Anyone have info? I’m a novice and have had a blast learning about mechanical watches and clocks! Thanks Bob for this wonderful website.

Thanks,

Glenn

[Bob Tascione]

Welcome to the forum Glenn!
Bestfit catalog #111 lists it as 310-5318, 310-5320 and 310-5321 depending on what year the clock was made.
Here’s a link to a little info if you haven’t seen it yet.
http://www.cockpitclock.com/JAEGER%20LECOULTRE%20CHRONOFLITE.html

Possible that the part you need is the same part in all 3 movements. Not sure about that though. Also read if the balance cock is held down using 2 screws then it’s a 332. Don’t know if that’s the case though. Just passing that tidbit of info along in case it happens to apply to your clock.

Enjoy Glenn!
Bob

[bamadadof3]

Exactly what I was looking for. Just signed up for matsys at Mccaw so I could also get a free set of bestfit books. Can’t beat that deal! Thanks so much Bob I already found what i need from your info.

Glenn

[bernie weishapl]

Welcome Glenn. Good to have ya here.

[bamadadof3]

Ok rookie noob question. On this clock it has one shaft that has a cog wheel on each end and it runs through the back plate. In the picture I circled the exact wheel as it sits on the back plate. This wheel runs some of the chrono functions that are on this back plate (I am guessing) and then on the other end of the shaft it has a wheel that directly connects to the escape wheel. The shaft comes out of that wheel rather thick and then right before it enters the jeweled bearing in the back plate it narrows down to fit through the jewel and then attaches the back plate wheel.

Here is my problem- I either broke this during dis-assembly or it was already broke but either way it broke right at the point that the shaft starts to narrow. I am assuming this shaft was originally 2 shafts that screwed into each other? It might have been milled as one complete piece but I really can’t tell.

Here is a video showing the problem.

[https://www.youtube.com/watch?v=VRezYC7IFts&list=UU6LkqHihMlb_Rj21lK2QpOA&index=1 ]

here’s the first question- How did the factory assemble this? Neither cog has a set screw or anything that allows you to remove them to facilitate the removal from the back plate!!!! Is it a simply pressure friction joint that is simply pressed onto the shaft? I don’t know who to remove the cog.

Second question– How would I repair this? I will go ahead an make an uneducated guess that you could drill the end out of the larger shaft to allow a new thin shaft to be inserted. I’m guessing both shafts would need to be threaded so the new shaft holds tight together? Then I could insert it back through the jeweled back plate and push the wheel into the new shaft?

As you can see I’m kinda lost here. I do not own a lathe yet so If my solution is the answer does anyone want to tackle it?

Here’s the pic of the back-plate.

[bamadadof3]

Thanks for any help in advance and I can get some better pictures of the actual shaft and cog wheels is necessary.

[bamadadof3]

https://www.youtube.com/watch?v=VRezYC7IFts&list=UU6LkqHihMlb_Rj21lK2QpOA

figured out how to insert a link… sorry….

[Bob Tascione]

Hi Glenn,
That should be your chrono driving wheel which will be a press fit onto the 4th wheel. They can be removed by either using a tool made for that purpose or by carefully prying it off with a set of tiny pry bars. The tool I have is made by Bergeon and resembles a hand or cannon pinion puller only with a different pulling config. using three prongs. That description probably confused the heck out of you. I’m traveling right now so not able to take a pic for you. I’ll check online and will find a pic and post the link up here. In most cases (you won’t need to concern yourself with this as far as your clock goes since the section of arbor holding your gear is broken) it’s good practice to REMOVE the balance and pallet lever as a great deal of torque can be delivered to the escapement when fiddling with anything on the 4th wheel. This torque can damage pallet stones. I put this here in case someone reading it is working on a chronograf and wants to remove this gear.
Got to run for a bit but I’ll look for a pic in a little while and will post it up here for you Glenn.

Adios for now,
Bob

[Bob Tascione]

Hi Ren,
Here’s a page at Ofrei that has a few different sizes of the driver wheel removers. Not cheap and the pry bar can do the job for you. For those interested in doing chrono work though this page may be helpful.
http://www.ofrei.com/page_209.html

Enjoy,
Bob

[bamadadof3]

Thanks for the reply Bob and your right it is the 4th wheel. I was able to take the .45 MM thick shaft out of the chrono wheel with a pair of pliers. I am attaching some pictures for more questions. All I have to do now is drill a new section where this broke off and insert a new .45 MM shaft and cut to the correct length then reinsert through the back plate jewel hole and push the chrono wheel back on. My problem is finding a way to drill into the 1 mm shaft without a lathe.

Now – look at the 4th wheel and how it attaches to the 1 MM shaft. Is this also just pushed on and held on with friction? If so- can I use my staking set and tap it off so it will be easier to get it drilled on the other end or would pushing it off be a bad idea? I guess I worry that pushing the wheel back on the shaft after I drill the end might create a problem? Tonight I’m going to experiment with some old wheels I have in the parts box but I’m not sure if they are designed exactly like this one anyway. My assumption is that a lathe with the correct attachments can be set up to drill (is pivot a better word?) the end of this 1 MM shaft (to accept the new unbroken .45 shaft) without removing the 4th wheel from the shaft.

Bob I looked at the tools you linked and now understand how they are put on and can be removed. Thank you.

pics:
This is Bottom of the 4th wheel which I wonder how it is attached is it also pressure/ friction fit and see question above about pulling it off and re-installing later.

This is the 4th wheel with 1 MM shaft. Top part is where the break occurred with a .45 MM joint.

Close up view of break and section that I need drilled to install a new shaft.

Full piece except I didn’t put the cHrono wheel next to the smaller shaft

[bamadadof3]

Bob I also appreciate the tip about removing the pallet so it can’t be damaged while I fiddle with this 4th wheel set-up. Makes sense and I wouldn’t have worried about that unless I had read that.

Thanks for the tip probably saved me a ton of headache.

Glenn

[Bob Tascione]

Hi Glenn,
You’re welcome. Sorry for not responding to your question for a couple of days but I’m away from home still and not finding much time to jump up here.
The wheel is most likely riveted onto the arbor. The serrated looking seat that passes through the wheel is what’s left of the pinion leafs after it’s been turned down a bit. There’s usually a small undercut in these leaves to use for riveting the gear in place. The wheel can be removed and replaced accurately in most cases but not always. I usually try to do arbor repairs such as re-pivoting with the gear in place. Not having a lathe to do the work will make the job more difficult for you. There are ways to make what’s called an applied drill jig out of a piece of flat stock but might be more trouble than it’s worth for you. Might try to find an old movement somewhere that you can salvage the part from or ask up here if anyone might want to take on the job.

Bob

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