Although there are some amazing AP ROOs out there, the CP is and will be my last one. I'm just too paranoid that my wrist will also stop working while wearing this beautiful "timebomb"...
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Latest JF ROO - Stuttering Sec@12
- Thread starter tr0y
- Start date
You know I have 1 JF 44mm panda bought m2m- it moves the second hand if you bump or swirl it- winding sets like a rotor malfunction and the back winder plate has its own momentum.... what to do- Slaught any ideas- its a mint watch just a shame. All my earlier roos run fine. And where to find a servicer in Ausrayyyylia.
Just for explanation.
Here you can see one reason why the second hand is stuttering.
There is a small gap between the last wheel and the second last. That gap is a reason why the last wheel don't turn smooth like the wheel in the middle. In total you have 5 wheels for the sec@12 transmission and between every wheel can be a gap.
https://vimeo.com/124612132
Sent from my iPhone 6
Here you can see one reason why the second hand is stuttering.
There is a small gap between the last wheel and the second last. That gap is a reason why the last wheel don't turn smooth like the wheel in the middle. In total you have 5 wheels for the sec@12 transmission and between every wheel can be a gap.
https://vimeo.com/124612132
Sent from my iPhone 6
That does look like an extremely poorly toleranced or plain miss-drilled assembly. How do they get away with it? If the basic movements were made as badly, they'd never end up with watches that worked...
My Ap Chronopassion JF model has the same problem with the sec at 12 !!!
Seems to be only with the Chronpassions this small issue !!
Other models not wich I recieved
Seems to be only with the Chronpassions this small issue !!
Other models not wich I recieved
I have been working with two JF sec@12s for the last 7 hours to try to understand why this problem of stuttering seconds is so common. Noob sec@12s benefitted from a certain drag created through poorly machined pivots/bridge taps. The JF bridges are better machined and present less drag, so the the gears shoot forward and backward easier, creating a jerky motion. The other problem is that JF sec@12 has not really improved the gear machining and there is significant gear chatter in the last two gears of the sec transfer. I have developed a few modifications to alleviate this problem which have nothing to do with graphite, lubrication or extra jewels.
Fazit: It requires a tremendous amount of care and attention to assemble a sec@12 properly. I do not think the factory that assembles these has the time to invest in this care.
Am I correct to say then that, as a buyer, this stuttering problem cannot be detected from a QC photo of the timegrapher reading? Or can it?
TDs would have to provide high resolution videos of the seconds subdial for people to detect a stutterer.
This really makes more cautious when buying a ROO. I think i was lucky that my blue screw a7750s in an IWC and franck muller are quite okay. They hardly have any power reserve when not wearing it but i have accepted this flaw as reps are much cheaper than the gen.
So you must remove all 5 wheels Slaughter 
and if you remove then the Top Plate you will see why the stuttering comes... The 5 Wheels are also an little Prob but the the Wheel that came directley from the 7750 to the Chrono Modul is pressed wrong... I had now a few JF Sec@12 and everyone was different.
Some was pressed really hard on the CP and some was too loose (High) and the Second Hand Stops when the watch runs over head... If you check these both Wheels and Clean and Lube the Jewels the Second Hand will sweep much better. It's not 100% stutter free but it runs ok then.
So if you give the whole Movement an Complete Service I wouldn't to worrie too much...
The Movements that I had Serviced runs all Stable I can't see any Prob on the Timegraph...
that the Asia Movements are not the best Quality that we didn't need to Discuss hehe but let me say this is only for the 77xx Movements... The A28xx have after an Service mostley the same Quality as an gen ETA...
and if you remove then the Top Plate you will see why the stuttering comes... The 5 Wheels are also an little Prob but the the Wheel that came directley from the 7750 to the Chrono Modul is pressed wrong... I had now a few JF Sec@12 and everyone was different.Some was pressed really hard on the CP and some was too loose (High) and the Second Hand Stops when the watch runs over head... If you check these both Wheels and Clean and Lube the Jewels the Second Hand will sweep much better. It's not 100% stutter free but it runs ok then.
So if you give the whole Movement an Complete Service I wouldn't to worrie too much...
The Movements that I had Serviced runs all Stable I can't see any Prob on the Timegraph...
that the Asia Movements are not the best Quality that we didn't need to Discuss
hehe but let me say this is only for the 77xx Movements... The A28xx have after an Service mostley the same Quality as an gen ETA...That first gear from the 7750 chrono module is definitely a problem sometimes. If you press it down firm for a tight fit to pinion, and to get least friction against upper bridge, then there is height mismatch with the next gear. It is really a matter of give and take with those two gears, but if you do not have a smooth output already with the first two gears, you can forget about the output on the later gears.
What I find strange is the height mismatch on the last two gears. There is a tremendous problem seating the final gear when installing the bridge at this point. To solve this I have been inverting the usual position of the second to last gear, to ensure more meshing between the last two gears, so that the second to last gear is installed upside down with the nickel-plated pinion facing up (exactly opposite to what Chris shows in his video).
There is also often a problem with the way the jewels are set in the final bridge: in fact that is why the movement factory is installing that little gold-plated washer on the final gear, to alleviate this problem.
Finally, these gears need to be absolutely clean: I am constantly manually cleaning them and examining them before final installation. Any little dust or fiber will impair functioning significantly.
What I find strange is the height mismatch on the last two gears. There is a tremendous problem seating the final gear when installing the bridge at this point. To solve this I have been inverting the usual position of the second to last gear, to ensure more meshing between the last two gears, so that the second to last gear is installed upside down with the nickel-plated pinion facing up (exactly opposite to what Chris shows in his video).
There is also often a problem with the way the jewels are set in the final bridge: in fact that is why the movement factory is installing that little gold-plated washer on the final gear, to alleviate this problem.
Finally, these gears need to be absolutely clean: I am constantly manually cleaning them and examining them before final installation. Any little dust or fiber will impair functioning significantly.
put these little Gold Washer into the Trashcan... I have put it away everytime this gives the gears too much pressure... Maybe there are some Plates that have Big tolerances but by the most Movement i have remove them.
If you put Lube on that Jewel look what happend with the little washer... The oli will be come true the Jewel and the Washer... This idea of the Chinese is B...shit... Sorry to say...
I had one Movement where the little Washer stoped the Minute Hand directley... So Watch also that the last base Plate isn´t tighted too hard with the Screws in the middle... These Plate is soooooo small and give pressure also on the Gears...
So the Sec@12 Movements needs an really good care and Handling... Don´t Service these in hurry...
If you put Lube on that Jewel look what happend with the little washer... The oli will be come true the Jewel and the Washer... This idea of the Chinese is B...shit... Sorry to say...
I had one Movement where the little Washer stoped the Minute Hand directley... So Watch also that the last base Plate isn´t tighted too hard with the Screws in the middle... These Plate is soooooo small and give pressure also on the Gears...
So the Sec@12 Movements needs an really good care and Handling... Don´t Service these in hurry...
Washers make sense when the jewel is recessed in the bridge.
Uwe used to play a thin piece of paper under the final bridge to create more breathing room for the gears on top.
Uwe used to play a thin piece of paper under the final bridge to create more breathing room for the gears on top.
For the first time, I came across this problem. The sec@12 stutters quite badly. Never had this problem before. Should I leave it till I definitely need to get it serviced?
Buddy it it's from your new piece get it changed. Those are time bombs. Alternatively you can service them and get them running well!
Does anyone know of a TD that will do the full service required to alleviate the stutter on these right off the bat when I order a new watch?
If not, who do you recommend for service CONUS? My local watch guy does most things for me but said he would not want to work on this one because he can't fully identify the problem.
If not, who do you recommend for service CONUS? My local watch guy does most things for me but said he would not want to work on this one because he can't fully identify the problem.
Everybody invokes this idea of a "service" as a final end-all solution to the stuttering seconds problem. But to disassemble clean and reassemble the watch is not enough to solve the stuttering problem. In many cases, a clean and oiled movement will just make the stuttering worse.
