Mawcul
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Does anyone know if the Sellita SW330-2 GMT movement can be used as a replacement for the VR3185/6 movement?
Interesting indeed. Two of the issues may be related to the same problem: dirt or engraving debris in the movement. If the movement is dirty then it will have a lower amplitude (this is well known). But I’d guess the dirt may also be behind the reset issues. When you press the reset pusher (red arrow), it pushes the reset lever pin (green arrow), which pushes the chronograph reset arm pin (yellow arrow) inwards. This action causes the reset hammer assembly to slide inwards (black arrow) which causes the reset hammer (cyan arrow) to push against the cam on the top of the vertical clutch (not visible).@dogwood
I received a vsf 126500 with DD4131 and I have a few things that leave me perplexed. I have a vs3135 and a vs3235 and their second hands run smoothly, while the chronograph second hand of the dd4131 runs, in some places, in jerks. I read in your beautiful thread about the 4130 that you had a similar problem and you solved it with the original wheel? It seems strange to me that no one else has ever noticed or complained about this... then it happened to me already 2 or 3 times to reset the chronograph after timing more than 20 minutes and the hands were unable to reset, I repeated the reset but nothing, I pressed start and then reset and everything was back to normal. this has happened several times... despite the movement being +-1 per day, I found the amplitude to be 230 and it makes me think it needs a good service. sorry for my many questions... after all I could live with it until the service where the balance and chronograph seconds wheel are installed, but I am concerned about the resets not happening and the low amplitude...
ok, thank you very much for the detailed answer. I'll organize myself soon for a complete overhaul and for the liga wheels, did you solve it with just one and an adequate assembly? or do you recommend replacing both?Interesting indeed. Two of the issues may be related to the same problem: dirt or engraving debris in the movement. If the movement is dirty then it will have a lower amplitude (this is well known). But I’d guess the dirt may also be behind the reset issues. When you press the reset pusher (red arrow), it pushes the reset lever pin (green arrow), which pushes the chronograph reset arm pin (yellow arrow) inwards. This action causes the reset hammer assembly to slide inwards (black arrow) which causes the reset hammer (cyan arrow) to push against the cam on the top of the vertical clutch (not visible).
As you can see there’s a lot of sliding involved in the reset function. Each of these metal on metal sliding surfaces needs to be lubricated properly. The problem is that if there’s dust in the movement it will collect and stick to lubricated surfaces turning the lubricant into grinding paste. (This is why it’s so important for movement parts to be clean, and it’s also the functional reason behind pearlage and Geneva striping — the micro ridges of the patterns on the metal traps dirt before it can find its way to a point that’s wet with oil or grease).
Regarding the stutter of the chronograph seconds hand, you’re correct, that’s due to backlash in the system. There are two LIGA wheels in the gen movement that help eliminate this: the third wheel (which connects to the vertical clutch during chronograph operation) and the chronograph seconds wheel (which connects to the other side of the vertical clutch, and to which the chronograph seconds counter hand is attached). With these two LIGA wheels we eliminate any backlash between the escapement and the chronograph seconds hand.
Without the LIGA wheels the amount of stutter you’ll see depends heavily on the spacing between the gear teeth. A difference of microns could be enough to produce visible stutter. And since the chronograph bridge is secured by screws there are a lot of microns worth of variability in the system depending on assembly technique. You might have simply received a bad example where the bridge position leaves a larger gap between the teeth introducing more backlash and thus more stutter.
If chronograph seconds hand stutter really bothers you then it’s probably best to do both. I seldom use the chronograph on the Daytona that I did the swap on. My running watch is a different Daytona (my meteorite dial 116519 on an oysterflex)… and when I’m running I never look at my watch long enough to notice stutter.ok, thank you very much for the detailed answer. I'll organize myself soon for a complete overhaul and for the liga wheels, did you solve it with just one and an adequate assembly? or do you recommend replacing both?
meteorite on oysterflex is the best for me too! but since it's my first Daytona I preferred to stay on the black dial, maybe I'll add endlink and oysterflex next summer... maybe it's because I often stop to observe the fluidity of the seconds hands on the Submariner 3135 and on the Datejust 36 3235, compared to my daily work NH35 the difference is enormous. And it's even more noticeable on the Daytona chronograph hand! I imagine I received a particularly dirty VS / DD4131 and assembled by the latest apprentice arrival... now the search for the liga wheels begins (by the way, they are the same on the 4130 and on the 4131 right?) and the balanceIf chronograph seconds hand stutter really bothers you then it’s probably best to do both. I seldom use the chronograph on the Daytona that I did the swap on. My running watch is a different Daytona (my meteorite dial 116519 on an oysterflex)… and when I’m running I never look at my watch long enough to notice stutter.
I’m not sure if the LIGA wheels are the same. I’d say the chances are good that the chronograph seconds counter wheel is the same, but the third wheel is less likely due to the changes in the escape wheel. And the balance is completely different from the 4130.meteorite on oysterflex is the best for me too! but since it's my first Daytona I preferred to stay on the black dial, maybe I'll add endlink and oysterflex next summer... maybe it's because I often stop to observe the fluidity of the seconds hands on the Submariner 3135 and on the Datejust 36 3235, compared to my daily work NH35 the difference is enormous. And it's even more noticeable on the Daytona chronograph hand! I imagine I received a particularly dirty VS / DD4131 and assembled by the latest apprentice arrival... now the search for the liga wheels begins (by the way, they are the same on the 4130 and on the 4131 right?) and the balance
I’m not sure if the LIGA wheels are the same. I’d say the chances are good that the chronograph seconds counter wheel is the same, but the third wheel is less likely due to the changes in the escape wheel. And the balance is completely different from the 4130.
The pallet fork is also different. I did a tear down of a dd4131 in my watchmaking journey thread a few weeks ago.I thought the changes from 4130 to 4131 were limited to the balance wheel with its bridge and the escape wheel. But I have no diagrams, manuals or parts drawings to confirm this... thanks so much for your help!
Is it possible to buy SH3285-2 in Aliexpress, ebay, etc?Post updated to include the update to the SH3285 movement -- now called the SH3285-2 movement. So far we've seen this movement only in QF Explorer 2s, but we should expect to see it roll out into all GMTs / Exp 2s from factories that previously used the SH3285. Like the previous update to other SH movements, this movement moves the regulator and beat adjustor to point outwards making it look similar to Dandong movements. However, the hairspring coil direction remains a foolproof way to distinguish between the two movements:
- Clockwise coil = Dandong
- Anti-clockwise coil = Shanghai.
I haven’t found a source for the SH3285 on AliExpress. The closest thing I’ve found is this. But you can see that this isn’t a true Sh3285 since the date finger (and much of the dial side) has 3187 vibes. But the balance side of the movement looks like a vr3235. I know this movement won’t fit into a case designed for a vr3187, but it might fit into a case designed for an SH3285. And if it has a vr3187 style dial side it might be a reliable replacement for a broken Sh3285.Is it possible to buy SH3285-2 in Aliexpress, ebay, etc?