JaceBeleren
In response...
- 29/6/24
- 140
- 122
- 43
ZF actually. Don't think there's a big difference in the clone movement between the two factories other than ZF having better engraving.
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JLC MUT Moon 925 Movement Clone
- Thread starter Mitzyy
- Start date
ZF has engraved text on the bridges on the movement. APSF has the text silk screened (printed with ink) onto the bridges. The gen is obviously engraved, so you’d think the ZF would be the smart choice. But I’ve recently been examining the detritus at the bottom of my pre-cleaning watch glass and I’ve found that many of the movements in our reps come contaminated with engraving dust (metal swarf).
Note: the picture above is the debris I washed off a brand new DD3285 in a Clean GMT. I have no idea if ZF is better at keeping their assembly areas clean. But the fact that APSF prints the text and ZF engraves the text implies that this movement (like all clones) is manufactured “sterile” and is finished by the rep factories. While silk screen printing is obviously not gen-spec, it might come with the advantage of not fouling the movement with metal dust.
I wonder how much of the poor reputation for reliability this JLC movement has comes from a batch of these movements that got very dirty during assembly at ZF.
JaceBeleren
In response...
- 29/6/24
- 140
- 122
- 43
You'd expect the factory would take the plates off completely from the rest of the movement before engraving them, wouldn't you, if only because this would be much simpler. This would make it much harder for metal dust to get into the movement itself.ZF has engraved text on the bridges on the movement. APSF has the text silk screened (printed with ink) onto the bridges. The gen is obviously engraved, so you’d think the ZF would be the smart choice. But I’ve recently been examining the detritus at the bottom of my pre-cleaning watch glass and I’ve found that many of the movements in our reps come contaminated with engraving dust (metal swarf).
Note: the picture above is the debris I washed off a brand new DD3285 in a Clean GMT. I have no idea if ZF is better at keeping their assembly areas clean. But the fact that APSF prints the text and ZF engraves the text implies that this movement (like all clones) is manufactured “sterile” and is finished by the rep factories. While silk screen printing is obviously not gen-spec, it might come with the advantage of not fouling the movement with metal dust.
I wonder how much of the poor reputation for reliability this JLC movement has comes from a batch of these movements that got very dirty during assembly at ZF.
They absolutely must remove the plates for engraving if only to fit the plates into the fixtures on the engraving machines. I suspect the parts are even thoroughly cleaned after engraving. I suspect the problem is that re-assembly of the movement with the engraved plates happens in an area that's no too far away from the engraving machine shop and I'd guess that metal dust (technically "swarf") manages to contaminate the assembly space through poorly filtered ventilation or perhaps the parts are contaminated from dust in the air when the parts are dried after being cleaned post engraving. An ideal workshop has a positive air pressure gradient from the cleanest room to the dirtiest room (in a machine shop this typically means high pressure in the electronics assembly area, with air pressure dropping as you go to the machine shop, and the lowest pressure in a foundry area.
IAmShepherd
Do not accept unsolicited offers
- 18/2/25
- 14
- 5
- 3
I'm still very new to this community, so sorry if I ask a very basic question, but I've read that the 925 movement is known to have a lot of issues. However I've also seen that some of the JLC rep's also come with a miyota 9015 movement, which seems fine. Why would people order the 925 movement version instead of the other one?
For watches with a crystal caseback some people prefer clone movements. The clone movement option makes the watch feel like a closer replica of the gen to some people. But there’s nothing wrong with a Miyota powered rep other than the fact that Miyota rotor as loud; but so is the rotor on the clone 925. In both cases the rotor only winds in one direction so it spins freely and loudly in the non-winding direction.
IAmShepherd
Do not accept unsolicited offers
- 18/2/25
- 14
- 5
- 3
The automatic winding stystem of the 900s JLC series is a bit difficult. its actually a unidirectional winding system with three independend ratchets. one is holding back the manual winding way of force. One holds back the driving moment of the rotor towards the mainspring. the third one couples and decouples the driving wheel of the rotor towards the automatic mechanism. There is not really a reversing wheel bit a clutchwheel made of layers of brass to load driving momentum from the rotor towards the main spring. the freespinning noise of the movement is happening, when the third ratchet makes the rotor driving wheel run over the shark like teeth of the automatic mechanism. sounds complicated, and yes it is. 1960s technology tbh.
The damping spring for the center seconds pinion on this movement and the Patek 324 is a good design to prevent stutter in the center seconds hand. However, I actually prefer the Rolex and ETA design where the center seconds wheel has a large diameter. When the center seconds wheel is large enough in diameter there is no need for a damping spring because the backlash between the center seconds wheel and the escape wheel represents a very small angle once it gets projected out to the end of the seconds hand.the Movement also features an spring braked indirect second, so it's a bit more complex than a Rolex or ETA movement
Regardless, it’s very interesting to see how the problem of stutter was solved by JLC. Thank you for sharing these photos.
Or you make it like APS/ZF/AZF/BP (Dandong) for their IWC Big Pilot, a double indirect second:
DavidHuang
Franken Addict
They just released the V2 of the ZF JLC Moonphase, you should check it out. Not sure about the movement changes, though.