Asia 7750 movement in JF version NaviTimer: Do and Do Nots

[Slanglican]

Okay!
So, my new JF NaviTimer is keeping awesome time!! I may have lost a few seconds since Saturday - maybe!
When i got the watch, I went to wind it and it seemed very stiff and rigid as if it did not need winding but also sounded and wound as though hand winding is a function of the movement...
it certainly self winds and is hackable!
Is this watch hand winding?
Is there a specific power reserve?
how do I know when I need to wind the watch?
CAN I OVER-WIND THIS WATCH?

ALSO:

I may get laughed at for asking this, but I cannot find the answer...
Does this rep movement have a vertical clutch where there is no wear and tear on the movement with constant running of the chrono?

thanks in advance for all the help!

 

[Slanglican]

I should have put a question mark in the title! I’m sorry, did not mean to misrepresent!

 

[tkingjr]

Here is a post that will help. https://forum.replica-watch.info/forum/replica-watch-general-discussion/8907181-the-replica-paradox

There are many posts on this movement. Pros and cons. For example, the tolerance on the accuracy in seconds per day is large. Maybe as high as 10 seconds per day. I am fussy about the time of my watch so whatever watch I wear I set it in the morning to an atomic clock.

 

[Slanglican]

tkingjr well, I guess I got lucky bc I swear this thing hasn’t lost time yet... maybe a couple seconds since Saturday.. no joke! We’ll see over time though and also how it does on the other two. Gray dial from I don’t know factory and BP world..
just thumbed up qc on BP world and gray dial just doesn’t want to get here... it’s just stuck at Chicago airport for 12 days now...

 

[Slanglican]

tkingjr hey was I supposed to click the link within the link bc that post didn’t say anything except my a7750 movement is shitty and will break especially if I use the chrono! Ha!
I am unsure if it is an eta movement that I have in the navitimer or not... I do know I have used the chrono a shit load and it’s been fine. But I guess I got my question answered that indeed it does not have a vertical clutch...

 

[tkingjr]

Slanglican I have about 26-30 A7750 watches. I am just careful how I use the Chrono. In the 4 years of buying Reps I am replacing my first A7750 movement as we chat. Last year I started getting every watch I buy serviced before I get my hands on it. In general, I have had to send out more Omega's for repair than any other Rep brand.

Dealing with the problems of watches that cost 10% of Gen's is just the cost of the hobby. If you just deal with it you will enjoy the hobby more.

 

[Slanglican]

tkingjr That’s great to hear!
yea I’m excited for the BP world the most... should be here in a monthish...
most of my automatics atre simple Seiko movements I can just replace and the rest are just quartz chronographs.. so I’m looking forward to gettin to know the workings of things with the reps... but no I had not planned on servicing them before use.. I need to find someone who will do it at a reasonable cost and someone that knows what they’re doing...
so to be clear... this a7750 cannot be replaced with an eta that they were talking about in the thread you linked me??
I love watches and it’s a hobby but a newish one.. I’m not totally on the up and up with all the jargon yet...

 

[ETAWatchlover]

Slanglican the a7750 is a ETA7750 .ETA movement's are a brand/model of movement's .Our reps use a Asian Clone of the ETA movement .They are almost identical in function and parts but have a hit or miss quality so some people put original/reliable original ETA Movement's in their watches .

 

[Slanglican]

ETAWatchlover Well, I’ve ordered three in total. I posses one and if the other two function the same as this one is functioning [at least so far], I’ll be one happy dude!
Do you have any recommendations for a gen ETA if I ever need to replace?

 

[Spitfire63]

I've got a couple of 7750's and the time keeping and power reserve in particular are the best I've got, the one thing I've heard often is that the winding mechanism on the movement is particularly high geared and can have a tendency to strip gears if hand wound to vigorously, so I wind mine very slowly and cautiously when I need to.

 

[Slanglican]

Spitfire63 yeah that’s been my MAIN question is how to wind it! It feels tight ALWAYS! when I received it, it was running and right.. so yea I don’t know what’s too much as it always kinda feels the same! I can get a few clockwise turns that feel like it should be wound, but after that I’m always nervous something is about to pop!

 

[CaptainSplash]

The A7750 uses a rocking pinion mechanism - https://www.awci.com/watchmaking-ex...nion-engagement-eta-7750-and-similar-watches/

Sounds like your mainspring is a bit stiff, not unusual on A7750's - these movements copies of a Valjoux 7750 (now ETA), and can't be overwound as the rocker/pinion mechanism will decouple from the mainspring. That is what prevents the oscillating weight from overwinding the watch in the first place. You should be happilly winding 30 or so clockwise turns until the small seconds start ticking, and then let the weight take over. Not a good idea yo wind it up to the clutch disengaging, as it is harsh on the components, hence sticking to the 30-wind procedure is recommended (same advice for gen and rep).

Never a bad idea to get this one serviced though, they are known to be rough and dirty right out of the factories. Rep friendly watch makers are usually competent with the valjoux, and some of the parts are interchangeable between gen and copy. Having said that, if it bugs out clone Valjoux movements are a dime a dozen on e-bay, if you have the equipment to set the hands and the like.

Finally, regards continuously running the chrono - if this was an off the shelf valjoux, by all means, bearing in mind it increases movement wear and runs down the mainspring faster. But since we are talking rep movements, bad idea regardless the clutch engagement technique.

Sent from my SM-G988B using Tapatalk

 

[Slanglican]

CaptainSplash Hey, thanks for the info!!
Will I hear the clutch disengaging?
This watch hasn’t stopped ticking yet, so I’ll stop mini winding it..

it just feels so much different than my other automatics...

btw, your blue world pics almost made me regret getting the black dial.... confirmed gen pics last week! Hope to be wearing it before fathers day next month!
hopefully it isn’t as slow as the gray dial [stratos] Navi I’m still waiting on...