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User guide to the A7750 movement.

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Lucashly

I figured that I can ask this questions as I am a newbie at n the newbie section. . What is a chrono?

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Mazz

a stopwatch

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GenTLe
I figured that I can ask this questions as I am a newbie at n the newbie section. . What is a chrono?

 

Chronograph : https://en.m.wikipedia.org/wiki/Chronograph

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cbrian26wvu

I see this thread is quite a few years old, however, has the A7750 movement improved any since these were posted?

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Mbnafees

Solid info. Thanks. 

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pmaxcslt

This is a fantastic guide!!! Thank you!

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roye1195

Hi guys,

Wasn't sure where to post this - let me know if this is the wrong place.

I am a first time buyer looking to get https://puretime.io/big-bang-evolution-44mm-ss-black-dial-ceramic-bezel-on-black-rubber-strap-hub4104.html
I know this isn't a TD on RWG but is on RWI
I have been looking online and there seems to be quite a lot of issues with the A7750 chrono movement (more specifically with sec@6 & sec@12)

I have had a look at the first page of the forum with all the advice on how to own/maintain a 7750 movement - Very helpful - I will 100% be following this guide.

So my questions are
1. Is there a TD that specializes in Hublot replicas?
2. Is there a TD that specializes in the Asian 7750 chrono movement as I would like to reduce the possiblity of this failing as much as possible?
3. I see a lot of mixed posts on whether to service or not for different movements. Which of the below options would be best for the, expensive to service, 7750?
    a) Service when received and then again every 5 years till it dies.
    b) Don't initally service but do every 5 years onwards
    c) Use it as soon as it arrives until it breaks, then get it repaired/replaced (not sure if this is a good way to about it, however saw it mentioned so thought I'd include)
4. Where would be best to service, considering price to get this done (I live in UK)? After contacted the support team and they said they offer servicing for $120. Guessing this would be to the same standard as other places?
5. Is it worth getting this on purchase to avoid shipping fees/time to do so within the first year?
6. What is the average life expectancy on the 7750 movement
7. Is it worth ditching chrono replicas all together and going for something like the below with a more reliable 2824/2836/2892 movement (both beautiful watches but this has nothing on the chrono IMO)
https://puretime.io/watch-brands/hublot/big-bang-classic-fusion-45mm/classic-fusion-42mm-titanium-jjf-1-1-best-edition-black-dial-on-black-gummy-strap-a2892.html

 

Sorry for all the questions and thanks for the help :)

Roy

Edited by roye1195

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Glaude
6 hours ago, roye1195 said:

So my questions are
1. Is there a TD that specializes in Hublot replicas?
2. Is there a TD that specializes in the Asian 7750 chrono movement as I would like to reduce the possiblity of this failing as much as possible?
3. I see a lot of mixed posts on whether to service or not for different movements. Which of the below options would be best for the, expensive to service, 7750?
    a) Service when received and then again every 5 years till it dies.
    b) Don't initally service but do every 5 years onwards
    c) Use it as soon as it arrives until it breaks, then get it repaired/replaced (not sure if this is a good way to about it, however saw it mentioned so thought I'd include)
4. Where would be best to service, considering price to get this done (I live in UK)? After contacted the support team and they said they offer servicing for $120. Guessing this would be to the same standard as other places?
5. Is it worth getting this on purchase to avoid shipping fees/time to do so within the first year?
6. What is the average life expectancy on the 7750 movement
7. Is it worth ditching chrono replicas all together and going for something like the below with a more reliable 2824/2836/2892 movement (both beautiful watches but this has nothing on the chrono IMO)
https://puretime.io/watch-brands/hublot/big-bang-classic-fusion-45mm/classic-fusion-42mm-titanium-jjf-1-1-best-edition-black-dial-on-black-gummy-strap-a2892.html

Will try to give you helpful answers but remember to use the search function if you don't find something straight away.

1. TD doesn't specialise, they all can get the same stuff except for some rare things which some TD are better at finding, but Hublot isn't really concerned.
2. Same answer as above, plus even if they were, they wouldn't service it before hand without an added cost
3. a) If you can, it's good ; b) It's not that bad to use this method but you have to be aware that it may fail ; c) same as previous, that's the "I don't care, it's a toy watch" approach :D 
4. The A7750 is a complicated movement so the hardest part will be to find someone willing to service it locally (and you'll have to be patient). Price quoted is good as long as you are sure they'll be doing the work correctly.
5. If you go with the TD service, definitely get it done before shipping
6. Impossible to predict, it will depend on how much you wear the watch, in what conditions, etc... Could last 2 months, could last 5 years, could last 10 years
7. Ditching chrono movements that are not quartz is definitely the easiest way to avoid the problem, but if you like chrono that shouldn't stop you (as long as you are prepared for the failure risk). Other movements are more reliable but they can also fail. If you can find a chrono with a manual wind ST19 you can go chrono without hesitation.

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roye1195
1 hour ago, Glaude said:

Will try to give you helpful answers but remember to use the search function if you don't find something straight away.

1. TD doesn't specialise, they all can get the same stuff except for some rare things which some TD are better at finding, but Hublot isn't really concerned.
2. Same answer as above, plus even if they were, they wouldn't service it before hand without an added cost
3. a) If you can, it's good ; b) It's not that bad to use this method but you have to be aware that it may fail ; c) same as previous, that's the "I don't care, it's a toy watch" approach :D 
4. The A7750 is a complicated movement so the hardest part will be to find someone willing to service it locally (and you'll have to be patient). Price quoted is good as long as you are sure they'll be doing the work correctly.
5. If you go with the TD service, definitely get it done before shipping
6. Impossible to predict, it will depend on how much you wear the watch, in what conditions, etc... Could last 2 months, could last 5 years, could last 10 years
7. Ditching chrono movements that are not quartz is definitely the easiest way to avoid the problem, but if you like chrono that shouldn't stop you (as long as you are prepared for the failure risk). Other movements are more reliable but they can also fail. If you can find a chrono with a manual wind ST19 you can go chrono without hesitation.

Thanks for all the info, really helpful.

Think I'm gonna start with a simple (non-chrono) watch first and go for this next. :)

Edited by roye1195

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Beechjet

Any ideas if the new A7750  day disc is interchangeable with eta7750? Like this one! Thank you! 

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GenTLe
Any ideas if the new A7750  day disc is interchangeable with eta7750? Like this one! Thank you! 
It should be. The differences between Asian and Swiss are minor, like pinions diameters.

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ShitBonerMcQueaf

Such helpful information. Thank you!

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Yankee1006

I now Know how I killed my watch  Didn't now about the 

Don’t re-set the chrono with the seconds hand anywhere but between 10 and 2 on the dial.  My second started slipping and now the watch is dead

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matbosh

Hi all, 

i'read all the topic, but did't find the info i need.

Bought a OMF Omega SM 300 Chrono with A7750 movement 1 month ago. Everything ok, never, (yes, never) used the chrono...afraid the fail of the watch.

yesterday i noted the minute hand  at 3 o clock moved of 1 min. Tried to start/stop and reset the chrono after 2 min but the hand return to 1 position (not vertical). I really followed litterally all the suggestions in this topic.

Any suggestion to make it return to the original vertical position?

I never used the Chrono, maybe a small hurt? I don't rememeber to had it...but...

Many thanks to all for your ideas, suggestions, experience.

 

Edited by matbosh
add more info

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Nexus9

Hey guys,

Thanks for the useful info, this is a common movement that us chrono-types run into, and I've had many of the symptoms listed here.

I just read the whole post looking for the answer to this question that popped into my head when reading Greg's "list" on the first page:

"2. Yes, the 7750 rotor is usually that noisy wink.png

The 7750 rotor only winds in one direction."

without finding an answer.  Which direction winds the movement?  Inquiring minds want to know!

Thanks

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FoxWilde

@Nexus9 clockwise

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Nexus9

Well, Daaayum!  No wonder mine's been running in reverse!

Only foolin'...  thanks, Fox.

Edited by Nexus9

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Nexus9

So in searching for a new chrono, I find a lot of the A7750 movements (of course) and I used to kind of snub the less expensive models which did not have a working minute/hour hand at 3 o'clock.  After reading this (really helpful) post, it almost seems like the watches with a non working 3 dial might be a better choice, no?  More reliable?

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Nexus9
On 20/03/2020 at 11:15, FoxWilde said:

@Nexus9 clockwise

I just want to add a little here for the generations to come who may be reading this post (and for those using a watch winder, like me).  I did a little research on a 7750 movement I had lying around, and  "clockwise", in this case, means "clockwise if you are looking at the back of the watch" - which is actually counter to the direction of the "clock".  If you are looking at the face of the watch, the rotor turns counterclockwise to wind, so you would want to set your winder to run clockwise - if the case of the watch is going clockwise, the rotor is turning counterclockwise, and winding the watch. 

As Obi Wan would say (if he were FoxWilde), "So what I told you is true... from a certain point of view"

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Nexus9

Also, I thought it might be helpful to see this "transfer bridge" that everybody keeps talking about:

PnLBW.jpg

The red arrows point to the three native shafts of the 7750 movement at 12, 9, and 6.  By default, the 9 shaft is the seconds shaft. 

To get the chrono shaft at 3, an entire bridge is added to the face of the watch, over the date wheel, which is why the date wheel seems to be sunken on many of these models.  In this case (a Planet Ocean Omega with hours and minutes at 3) the 6 shaft is running the minutes through a set of gears from the bottom of the bridge, while the 12 shaft is running the hour hand on the 3 oclock chrono dial.  Of course, none of these shafts are on jewels, or probably even lubricated when assembled at the factory, so you can see how much of a load this would add to the movement.  This might help clarify why running the A7750 chrono much is not a great idea.

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GenTLe
21 hours ago, Nexus9 said:

 This might help clarify why running the A7750 chrono much is not a great idea.

Actually with the 7750 6/9/12 it's not a big problem. With these ones what scares me more than running the chrono itself, is lo let it run quite a lot and then stop and reset. The reset hammers aren't now just operating on a single cam on the shaft with the hand on top, they are operating on 3 more interconnected gears. The possibility of breaking something or having the gear fitted on the pinion to slip when the reset hammers strike is not at all a remote possibility...

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Knowone

I am really into the 7755 movement.  I hear it’s an expensive problem to fix.  Thanks for the tips.  

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flogtwo

Thank you for that I info, never knew about resetting between only 10 to 2

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wisedennis

Never use the chrono 

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