AP 15400 instant date change mod for 3120 movement

[dogwood]

I posted about this mod over in my Watchmaking Journey thread, but figured I'd make a post here for more visibility. The clone 3120 movement found in reps of the 15400 is great except for the fact that it doesn't have an instant date change at midnight like the gen 3120 movement does. I recently got the chance to work on a modded clone 3120 movement which had an instant date change mod installed. Here's a pic that compares the modded (red) and unmodded (blue) 3120 movements:



The mod itself consists of three parts: the date gear, the spring, and a part that looks like the number 6.



The mechanical interaction between the three parts is very clever and enables an instantaneous date flip at midnight:

Here's what it looks like when the dial and hands are in place.

I'm not sure which modder in China came up with this design, or if it's a copy of the gen design. But I thought it was cool and worth sharing.

 

[Woundup]

That is a very cool spring design, and thank you for sharing.

Seems like a simple enough revision to enable a desired feature - the factories must be saving it for future version releases...

 

[germanynrw]

Does anyone know, if this is possible by the 15450?

 

[dogwood]

Does anyone know, if this is possible by the 15450

Yes it is. Any AP that uses the 3120 movement can have the mod applied.

 

[j21]

Amazing
Thanks for sharing

 

[germanynrw]

Hope I find a watchmaker in europe who can do it.

 

[GeneralRep]

If anyone hears of or knows someone that can perform this mod, preferably one of our own, but "trusted" watch-folk within the EU also fine, please do let me know! Would love to do this mod to my 15400. Perhaps with a rebrush also. Pinging @legend
Is this a mod you might be considering adding to your repertoire?

 

[legend]

Is this a mod you might be considering adding to your repertoire?

It’s a mod I already have been doing for the past 6 months. I’m not in eu though.

 

[dogwood]

It’s a mod I already have been doing for the past 6 months. I’m not in eu though.

Where do you get the parts for the mod? It’s a pretty easy install, but I haven’t found any TD or Chinese modder who can sell me the parts.

 

[legend]

Where do you get the parts for the mod? It’s a pretty easy install, but I haven’t found any TD or Chinese modder who can sell me the parts.

All I will say is that I can get them. In fact I just ordered a few more sets for members here today. The parts are not available for general purchase. TDs do not have them and Chinese modders won’t readily sell them. It’s not impossible or exclusive to me though, just like buying specific spare parts for the 3120 or 4302 clone movements. I do expect them to be more accessible after the lunar new year please be patient.

 

[Slugger]

This is very interesting, ingenious even, but it’s storing a lot of energy in the spring before a violent release. I wonder how well that pin will hold up.

 

[Andy Bud]

It’s a mod I already have been doing for the past 6 months. I’m not in eu though. Can you get this kid done for me?

All I will say is that I can get them. In fact I just ordered a few more sets for members here today. The parts are not available for general purchase. TDs do not have them and Chinese modders won’t readily sell them. It’s not impossible or exclusive to me though, just like buying specific spare parts for the 3120 or 4302 clone movements. I do expect them to be more accessible after the lunar new year please be patient.

Can you get this mod done for me for a cost?

 

[Autobús]

@legend. Are there any reports of reliability issues with it? Asked a modder this past week for it and he will no longer sell them

 

[legend]

@legend. Are there any reports of reliability issues with it? Asked a modder this past week for it and he will no longer sell them

There are no inherent issues which I’ve encountered so far. There is no reason why your modder stopped supplying this unless he cannot get the parts. The production of the parts have stopped and this may be the likely reason.

 

[Autobús]

There are no inherent issues which I’ve encountered so far. There is no reason why your modder stopped supplying this unless he cannot get the parts. The production of the parts have stopped and this may be the likely reason.

Good to know. Not sure of his actual intentions for not selling the part but he did specifically quote his reason was for reliability concerns, whether that was his actual reason or not.

 

[Slugger]

I am a positive person and, while I have no insight, I’m hoping this was a proof of concept that can now be perfected. I won’t be surprised if a new and improved spring is in the works.