Sunken Date Mod

[APjumbo]

So I have a couple reps with the working chrono but sunken date. It really annoys me. I am attempting to remove the extra gear train to have a nicer looking date window.

By doing so, I may be messing up the depth that the crown tube aligns with the movement but figure I would try and see regardless.

Edit- another really good writeup

Breitling Navitimer B01 Chronograph 43mm - Sunken date wheel modification

Hi, I recently bought myself an GF Breitling Navitimer B01 Chronograph 43mm with an A7750 movement and a black dial on a black leather strap from Hont. http://www.hontwatch.ru/index.php?main_page=product_info&cPath=32_145&products_id=9142 The watch is very beautiful and one of my favorite...

forum.replica-watch.info

And another-

Navi Sunk Date Wheel Fix - Freeze chrono at 3?

Yes, it is possible, but maybe I am referring to the ancient mod you just mentioned! Would you have a link to that old mod? I have been away from the boards for the past couple of years, but am still an avid replica collector and amateur "modder". I decided to chime in here because I have just...

forum.replica-watch.info

And another-

A Solution for the Sunken DW of the Asian 7750

From Fransico on RG etc. Some gen watches employ an ETA 7753 movement. This movement is quite similar to ETA 7750, but the minute counter is at 3 position, whilst 7750 has the minute counter at 12. As there is no rep of the 7753 movement, reps factories use a modification of the Asian 7750. This ...

www.rwg.bz

Remove Caseback and rotor


Two screws holding deco plate on. Here is the first. The second is directly across, Has same U shaped notch in the deco plate.


Second deco plate screw




Deco plate is off



Movement



Pull three movement screws and tabs/feet



Pull movement holder



Gently push release button to remove crown



Hold pillow against the bottom, upside down, and flip over to drop out movement and dial.



Dial protector to pull hands off, watch out they like to pop and fly.










Wedged dial protector in there and popped off chrono hands, almost lost one.




Pull out these tabs at around 1:00 and 7:00 to release the dial



Dial is off, you can see the extra gear bits.








Started by removing this screw. Taking photos in case I need to reinstall everything. keeping parts in a tray in order.


Then this brass looking small wheel



These bigger gears are part of this whole assembly, so I removed the two screws holding the plate down.


Second plate screw


Loose gear rolling around



Gotcha



Removed three screws holding down this spacer.



Spacer is 0.5mm thick



Not sure what to do about these, crossed my fingers and used a hands puller to pop them off.



Like this.


Dial is still sitting high. Fack.



Checking depth to see if its the longer dial feet holding the dial up.


Still hideous.



WTF?



Chopped a bit of feet off. I dunno? [Edit- Don't shorten the feet, not necessary.]

 

[P..DR..D]

There was a guy I saw in M2M who did this to a number of Breitlings, it was his thing apparently as the Navi's are known for sunken DW (example below)

GF Breitling Navitimer 43mm Panda - Franken - 2xProfAR - Flush Date Wheel Mod

Introduction HVS approved by @mclarendude Hi, This is project number 2 of the new pieces I have been working on lately. For those that know me on the forums, I am a big Breitling enthusiast who has an obsession with making Breitling reps look as close to gen as possible. Please look at all...

forum.replica-watch.info

I have absolutely no idea if the movements are even remotely similar, but I saw sunken DW, thought of @neon_7 & we're all one big information sharing community, so

Good luck with your project & hope you get the outcome you desire.

 

[APjumbo]

The chronomat he sold is the reason I wanted to try this. My chronomat will be next if I am successful. Experimenting on the Omega first, my sacrificial lamb.

There was a guy I saw in M2M who did this to a number of Breitlings, it was his thing apparently as the Navi's are known for sunken DW (example below)

GF Breitling Navitimer 43mm Panda - Franken - 2xProfAR - Flush Date Wheel Mod

Introduction HVS approved by @mclarendude Hi, This is project number 2 of the new pieces I have been working on lately. For those that know me on the forums, I am a big Breitling enthusiast who has an obsession with making Breitling reps look as close to gen as possible. Please look at all...

forum.replica-watch.info

I have absolutely no idea if the movements are even remotely similar, but I saw sunken DW, thought of @neon_7 & we're all one big information sharing community, so

Good luck with your project & hope you get the outcome you desire.

 

[APjumbo]

This is where I am stuck at what to do.

Apparently it is these two posts that hold those gears at 6:00 and 12:00

Do I snip them off and make this mod irreversible?

Do I remove the datewheel and try to remove the next plate and remove the gear these rods are attached to?
More risk of me buggering something or losing one tiny part.

What if I make it irreversible and by removing 0.5mm of gap, the dial either sits 0.5mm from the rehaut (rehaut spacer?) or the crown tube and keyless are 0.5mm apart.

I am wondering if the correct way is to have a second datewheel handy, glue two together. Reinstall the 0.5mm spacer. There isn't any gears to interfere with the higher datewheel, The pinions/posts holding the hands will remain at the correct height, the crown stem will be back to normal height/depth/position. So in other words, just remove the gear train and stack on a second datewheel (below the rep datewheel of course)

Going to step away for a bit and have a think.

Maybe someone out there has a better idea.

 

[P..DR..D]

Sweet, subscribed so and look forward to seeing the progress, best of luck

Hopefully if @neon_7 sees this he will share some wisdom

 

[APjumbo]

Pretty sure after reading through Neon's threads he uses an extra datewheel on top.
Usually a gen datewheel on top of the rep one.

I'll be looking into gen datewheels........down the rabbithole we go!

 

[mrsullivan]

@neon_7 does magic with sunken DWs on Navitimers. The mod involves freezing the 3pm subdial, but unless this really is a need for you it does'nt make any difference in the way other functions work.

I have one from Neon with a gen DW, the DW height is close to perfect.

 

[APjumbo]

@mrsullivan That there is a beautiful navitimer.

I might attempt making a spacer on the lathe at work and having it flush with a working 3:00 subdial.
It probably won’t work out but I’ve got the time and stubbornness to try.
I have found a few useful threads.
A crystal gasket sanded down might also do the trick.

 

[njh225]

- please no advertising outside the sales area -

 

[njh225]

- please no advertising outside the sales area

My apologies I didn't realise this.

 

[APjumbo]

So I didn’t expect to give up so easily. Shame….Shame…..(bell rings)

After measuring the thickness of the gear plate at 0.8mm and looking at it with the spacer back on, I can’t imagine how a datewheel will fit above this upper gear and below the dial.
Adding more spacer is a bad option and will lower the height of the hands too much.
Unless maybe I thin the dial down, then add dial dots between the outer spacer ring and bottom of dial to create more gap.
This all seems too extreme, thinning the dial, thinning the original datewheel down super thin without destroying it.

I am pretty sure I will just leave the extra gears for the 3:00 position removed and continue with raising the datewheel with a second datewheel overlay.

 

[APjumbo]

Finally had time to get back to this.

New 7750 datewheels arrived from germany (ebay)



So, I had marked with a sharpie roughly where the dates aglined.
The new 7750 datewheel dates don't align the same as the rep, So I had to mark the backside before clipping the teeth off the rep wheel.




I used clippers first to clip the teeth off, then filed down with a file.



I had tried gluing them together with GS cement, that worked, but when I installed I could see that the date still wasn't raised enough.
Also, I hadn't trimmed enough on the inner diameter and fgured it would start to rub, so need to sand more off.



I had also glued the right hand chrono wheels to the underside of the dial, but you can see here that the wheels stick out past the centre piece and would interfere with the date. So either had to cut these wheels or glue the hands straight to the dial face.



Pulled the dials apart and did some measuring.
1.15mm from where the datewheel sits to to the underside of the dial.
So this time I used thicker doublesided tape between the datewheels to raise the rep datewheel further.
1 mm thick now, out of 1.15 mm should leave 0.15mm wiggle room so that the wheel doesn't rub the underside of the dial.

Sanded down the inner diameter some more as well using a small rounded file.

 

[APjumbo]

Double sided tape also gave me the ability to adjust the date numbers so they were perfectly centered.
Assembled, tested, dissassembled, adjusted, about a dozen times. Fack.

 

[APjumbo]

Way better!!!!!



One more adjustment after this pic to get it more centered.



And then..... typical APjumbo build
I get the hands on perfectly, Looks great, all aligned, and......

Movement isn't working.

Fack.

I don't know why and I don't know uch about movements but I had a hunch it was to do with removing the gears, my assembly, or a keyless thing.

I remembered that one of the screws I used to screw the centre plate back down seemed long, so....... all apart again.

Yup, this screw was the wrong one, It was too long and touching something, so put a short screw in here.

 

[APjumbo]

Now in typical APjumbo style, everything has to be assembled twice, and the second time round I usually lose a spring or a screw or something goes flying across the room. I don't know why, it is just the way it is, every time.

This time, I get all the hands on perfect, was trying to get a smudge of the hour hand, ended up scratching it, stupidly thought I could buff it out with a tiny piece of cape cod. ugh, got a drop of cape cod liquid on the dial, tried removing with isoprophyl.
Not horrible, but not great.

Fack

Anyways, the chrono hand is drying, the dial has a light snudge now when you look at it at an angle, hopefully it doesn't show up once under the crystal.
Will finish tomorrow and share the results!

 

[ExtraExtra]

Nice job.

Is ETA 7750 datewheel font and size the default for Breitlings?

 

[APjumbo]

Nice job.

Is ETA 7750 datewheel font and size the default for Breitlings?

I don't think so, When I put a 7753 in my navitimer the font on the eta7753 datewheel was incorrect, and the single digits are turned the wrong way. But the eta7753 datewheel I have on there is centered nicely and I think that is more important than the font being slightly off.
Most people wouldn't notice the difference.

I don't know much about breitling specific stuff though.

 

[APjumbo]

Not sure it was worth all the trouble but glad I tried and learned a bit. Not sure if I want to risk damaging or mucking up my chronomat for the same result.

 

[APjumbo]

If I did it again I would probably cut the tiny wheel that holds the right hand chrono hands on and then glue that wheel on the underside. I’m not happy that the hands have already slipped/moved to the left a hair.

 

[ExtraExtra]

If I did it again I would probably cut the tiny wheel that holds the right hand chrono hands on and then glue that wheel on the underside. I’m not happy that the hands have already slipped/moved to the left a hair.

What would be the cause for the hands slipping? Not enough pressure?