Ar 1141 Locking It Self ?

[rogart63]

Have a enicar AR 1141 that has a strange behavior? It works very good when it in normal wear. But it can suddenly lock it self and stop working . Can't figure out why . Only thing that is needed to start working is by touching the second wheel a little . It has been serviced some month ago. By me . End stone of pallet fork was my thought but wouldn't that make the movement go bad on the timegrapher?

Edited August 30, 2015 by rogart63

[anilv]

Train problems? Mainspring new?

Go back to basics...check the barrel pivots...train pivots and jewels...escape wheel teeth...

Anil

[rogart63]

Train problems? Mainspring new?

Go back to basics...check the barrel pivots...train pivots and jewels...escape wheel teeth...

Anil

Have checked everything New mainspring . Had two AR 1141 movements and took the best of both . Only thing i couldn't  change was the pallet fork . That was broken on the first movement? Has checked for wear in the jewels also . Think i have rebuild the movement 5 times. 

Edited August 31, 2015 by rogart63

[frenchie]

Specks of dust somewhere ?

Ever noticed a pattern to the stopping (for example : always at the same time, when face down only....) ?

[rogart63]

No . Haven't notice anything special only that i stops when it get a hard hit . If i hit i with my hand it can stop . If i could only find a new or used but good pallet fork i would try that? 

Edited August 31, 2015 by rogart63

[Geo]

Hi Roger. How much end float is in the barrel? If there was too much, it might touch the wheel that sits between the barrel and ratchet wheel. Just a thought!

[rogart63]

Hi Roger. How much end float is in the barrel? If there was too much, it might touch the wheel that sits between the barrel and ratchet wheel. Just a thought!

Will check that .

[matabog]

If you change the pallet fork also change the escape wheel. I believe they are set in pairs.

[rogart63]

If you change the pallet fork also change the escape wheel. I believe they are set in pairs.

Could that be the problem? If i took the the wrong escape? 

[anilv]

escape wheel and pallet can work independantly, ie you can buy a replacement escape wheel and it should work as planned. Bear in mind that if the watch has a faster beat-rate then the parts will not be the same.

 

What is important is to view the interaction between the pallet stones and escape wheel, one should lock as the other unlocks. Since uffit runs for a while and only stops when you knock it this points to a something loose. Inspect the jewels really carefully with a powerful loupe.

 

In my first reply I mentioned barrel pivots, to elaborate, this must have very minimal endshake...there should be no marks which show that the barrel has been rubbing on the main plate or barrel bridge. It must be able to get 'cocked' at an angle. Also look at the centre hole and centre-wheel pivots , if not jewelled.

 

Check all pinions, cleaning sometimes fails to clear the gunge inside the pinion leaves.

 

 

Another thing to check,..is the hairspring level? Install the balance without the escapement (all other stuff) so that you can check that the hairspring sits level and the endshake is correct.

 

 

Finally, when mixing and matching used parts you need to bear in mind the fact that someone else was in there before you and he could have modified something.

 

For example, replacing a balance staff is a fairly common task, but if the watchmaker did not have the correct one handy he could have modified another staff to fit.. part of the modification could include reducing the effective distance between the balance cock and mainplate to accomodate a shorter staff.. this can be done by removing metal off the base of the balance cock or by pushing the jewel in the mainplate deeper in. Vice versa to increase the distance by inserting shims.

 

You need to work thru the whole watch... from barrel up to balance.. looking at each individual component, its pivots, its clearance and its interaction with the next wheel/part.

 

Tedious but part of the job..!

 

Anilv

[anilv]

adding to my post above.

 

You have one watch with a damaged pallet fork right?

 

When a pallet fork goes bang....either thru a broken pivot or pallet-jewel, what can happen is the mainspring power is released suddenly...this can really mess up the teeth on the escape wheel.

 

Anil

[rogart63]

adding to my post above.

 

You have one watch with a damaged pallet fork right?

 

When a pallet fork goes bang....either thru a broken pivot or pallet-jewel, what can happen is the mainspring power is released suddenly...this can really mess up the teeth on the escape wheel.

 

Anil

I think i broke the pallet fork when i assemble the movement . But not sure? Could have been broken before? 

I did however put the watch in the timegrapher today . Nice straight line and  +17 s/d .But i could see a little dot that was visable on the screen .Under the line . Could that be a bad or bent fork or wing on the escape? What is it called? Hope you now what i mean? Looks like the culprit is the escape . Shall change it as soon as i get the time. 

Edited September 1, 2015 by rogart63

[anilv]

Escape wheel tooth....hopefully you've found the problem!

Anil

[rogart63]

Finally got the time to look into this movement . And i think i found the problem . The small little bridge over the barrel was worn . There was a slight movement when i rocked the barrel . Lucky for me i had a replacement . Now it's tight and firm . And hopefully that will solved the problem with the jamming of the movement . 

[Geo]

It sure looks worn Roger, fingers crossed that this was the problem.

[rogart63]

Didn't work . Still jamming up .Now i have the pallet fork on observation . Looks good to .Picture coming 

[rogart63]

Here is the two pallet forks side by side . Top one is the one i am using now. Lower one has a broken pivot. But the lower was in the movement from the start. How shall do to  measure that it works? 

[rogart63]

Pallet fork mounted again .Looks like it works and can't make the movement lock itself without the balance . Could the problem be with the balance or the ruby pin. I have been almost everywhere with my sharp little Dumont tweezer and making small scratches.Looks like hell . But it is clean.   . 

[rogart63]

Anyone got a tip how to measure a pallet fork ? Where the stones should sit and in which angle?

[clockboy]

I don,t know if I did this correctly but when I replaced pallet stone I found one out of my stash that was the same size as the one still in the folk.

I then attached it at the same height as the existing stone using this gem of a tool I found on the Bay a few years ago. It worked so I presume this is the method.

 

P.S Notice the price $3.35 what a bargain.

 

 

[rogart63]

Finally got the movement up and going alright . Order a new or used? Pallet fork from oldswiss . Took some time to get it . But ones installed the movement is working great .No locking itself anymore . So the culprit was the pallet fork . Shall be great to return the watch to the owner again . After almost two month . But i am happy that i solve the problem :)

[Geo]

Great stuff Roger, it's a good feeling when a plan comes together! :)

[ricardopalamino]

Good work Roger . Great feeling when it starts to run properly . Perseverance won the day .  I was about to suggest that the hands might be hitting each other , or hitting the dial if the dial is not properly seated .

[rogart63]

I learned a lot on that movement . I think i have rebuild it 10 times . Look like crap with a lot of scratches from my tweezers . Mostly on the pallet stone bridge . Found some other small things on the way . So this watch will probably run an other ten years or more ..