knmwt15000

I and many others have reiterated this before:

IF the mod is successful, you will still be left with an inaccurate date font for the Breitling.

You can't use an ETA 7753 or a Breitling cal.23 datewheel, because it isn't the same size as the asian 7750 date wheel ( the swiss 7753/cal.23 date wheel is slightly wider). Unless, as you say, the top plate was machined with a recess to accomodate the bigger wheel.

So after all the hard work, you could still be left frustrated. Until someone comes up with the correct font...

Thanks for the note. I think a custom date ring made from scratch is the order of the day. Does anybody know what font Breitling actually use? I know they have the single digits oriented parallel to the tangent and the double digits perpendicular... If you can get hold of OEM datewheels from Breitling for the navitimer these probably could be modified and used. Can these be obtained?

Hi guys,

anybody got/seen a good copy of the ladies carrera wv2413

thanks

It's always exciting to see people take up challenges like this and forage new ground in the rep world. Awesome.

I hope it works out for you guys...as it would open up a whole world of improved quality and modding potential around here.

Thanks Toadtorrent. Glad to see a great deal of enthusiasm for this idea. I think we're reaching critical mass

I may have one in approx 10 days. In working order though. Will be a lot cheaper than cousins

If you can wait I can contact u then

Richard

Certainly can wait. PM me

Cousins have responded quickly to a request but don't have an image of their 3LZF1 without the dial, which I would very much like to see.

Yes, the solution seems easy. A friend of mine, about two months ago, gave to me the idea, quite similar to yours.

I am working on that just now. However, you need to modify some things. If you do not have a watchmaker lathe it is a very time consuming and difficult task. Tolerances are very tight.

I will post the results soon.

Francisco.

Great news Francisco. It seems that you're the man for this sort of thing around here. Nice work. On a side note I noticed that your regulator mod appears to have vanished into thin air. Do you know what the deal is with this and could you repost it?

FYI

Yes, the solution seems easy. A friend of mine, about two months ago, gave to me the idea, quite similar to yours.

I am working on that just now. However, you need to modify some things. If you do not have a watchmaker lathe it is a very time consuming and difficult task. Tolerances are very tight.

I will post the results soon.

Francisco.

Didn't realise there were two plates. In which case you could cut the first plate with a thin gap (for the spacers), and the top plate with a bigger gap (the same width as the datewheel) so the date wheel is recessed/flush with the top of the movement.

But yes, I can't see the issue apart from it being very small tollerances, and the pulling apart for later servicing. If the movement was the size of a dinner plate it'd be easy!

Good luck, I can't see any *major* issues apart from time.

(I'd mentioned doing this a few months back, and didn't get a reply)

Good deal Bibbs, I like your idea about recessing the first plate. This is the solution for the engine I pictured initially I'm sure. For the second engine, pictured by Rolexman (original from yodap) the job of modifying the plates is not needed. However, some support for the inner edge of the new date ring will likely be needed in the areas of the date window and the gears to prevent any inner edge dipping which may be visible in the date window and might interfere with the gears.

Last night I spotted your previous posts on the subject. Glad I'm not on my own with my thinking.

If you want to try this I can put you onto a dealer who can supply a bare A7750 MVT.

Col.

Thanks trailboss, do tell; that would be great

Cousins carry them SEE HERE

Part number 3LZF1

Good job fella. Sweet. Would love to see this though with the dial removed.

Sorry to rain on your parade, the only way to modify this movement is to make it the same design as the ETA 7753. And the only practical way to do this would be to purchase a ETA7753. Parts for ETA 7753's are not available, I have tried for years to get some...and I have worked on these movements for 4 years, there is no other solution...unless you have a watch parts factory at your disposal.

RG

Thanks for noting my point about optimism. Given the photos provided by yodap of one of these mechanisms I'd say that it is really easy to do. I just need to get my hands on one of these so I can get this done.

http://www.auctiva.com/hostedimages/showim...,0&format=0

I hope you take all this back when I manage it

http://www.auctiva.com/hostedimages/showim...,0&format=0

Greetz.

looks like it's actually from yodap

Theory is one thing, putting what your proposing into reality is another thing altogether. I would have to guess that you don't have any practical watchmaking experience.

Do you think you have started enough posts on this one topic ?

RG

Hi Watchdog. To be honest the more I probe it looks like this mod is fairly easy; based on what I've seen here and my engineering experience. I do some experience with watches. Lets try and be optimistic. THE main flaw with these watches is the deep recess of the date ring. Please try and be constructive.

Lol re posts. I figure that the best way to get appropriate responses is to ask questions in the appropriate forums. I may be new here but I'm not new to forums and I used to be one of those guys who lurks in one specialised area and wouldn't notice if somebody asked a question that I could answer if they posted it elsewhere. You should consider the internet fortunate that I'm keeping it to just this forum lol

thanks

p.s. looks like the image belongs to andreww

Tri-compax mod:

pic removed

It's not my pic but I can't remember whom it belongs to?

Nice find Rolexman!

Gee whiz. That thing is just about perfect for modifying. No need for cutting down anything just putting a thin lip on the existing date ring and bonding a new one above the gears.

Does anybody have any clues where this image is from?

Am considering modifying this mechanism so it has a far better date recess:

http://www.rwg.cc/members/Navitimer-date-f...677#entry657677

I need a working or broken engine to make a prototype on. Any body have a broken one that they could donate/sell to me? Or, anybody have an idea where these can be purchased? Or, at the very least which is the cheapest rep with this movement so I can go about getting that.

Thanks

I think what you are proposing will theoretically work....a "c" shaped date wheel that wraps around any overlapping gears and has an overall height that reaches the backside of the dial. Like this....

However I think the manufacture and modifications to the required parts will be so difficult that it probably isn't worth doing. Firstly the upper date wheel will have to be slightly thinner then the first plate to be able to clear the second plate gear train and also stay below the backside of the dial (not sure if they are normally that thin so you may have to make one). The first plate will have to be cut back far enough to accomidate the width of the date wheel since it will reside at the same level. Then the real trick.... in order to assemble/disassemble the movement the attachment of the two date wheels would need to be done so that you can actually get them appart. I suppose you could glue them as you built up the movement but you will never get it apart again....at least not without breaking it.

It would be fun to mess around with for sure. Let us know if you give it a shot.

Glad to see that people can envisage what I'm talking about and don't think it is too ludicrous an idea. I wouldn't say that the difficulty in modification is such that it probably isn't worth doing (since I'd give my right nut to have any of the 3,6,9 replicas without the ridiculous recess)

p.s. can't see your image

What I need to know is where can I get hold of an engine to try this out. Can the Asian engines be purchased somewhere? Does anybody have a broken one of these that I could have/buy to make a prototype with?

Thanks

Just a quick Q.

Could you not cut the top plate into two rings. A centre ring (that keeps the cogs in place) and an outer ring.

Then the inned edge of the outer ring (and the outer edge of the inner ring) could be thinned for a date wheel sized recess.

Then there could be a gap between.

This gap would be over the current datewheel.

Then a few spacers, and another datewheel on top.

Cheers for your comments Bibbs. You've pretty much the idea. Except you would need to do it to the second plate too; since there has to be a continuous gap around the engine for the date ring.

I gather you allready know a bit about watches?

If you can pull that off you would have a line a mile long of folk wanting the mod done.

Col.

cheers, lol

Erm, No. I just haz a clue that's all I'd bet that this can be pulled off.

By modding an already heavily modified movement, this could equate to something as reliable as a chocolate fireguard..

??

Thanks for the note but I believe that it is optimism that advances things such as technology.

Hi guys,

I've been pondering the 3,6,9 a7750 and the problem it causes with the depth of the date ring and I think I have an idea how it can be modified

http://www.rwg.cc/members/Navitimer-date-f...637#entry657637

any thoughts would be really useful

Thanks for your quick responses. I have found this, since I noticed that other models in the 3,6,9 configuration apparently use a similar (same?), modification.

Thanks to Francisco we have these of the Omega seamaster:

These show the engine with the dial on, the dial off, the first plate off, and the second plate off.

After seeing these I'm quite optimistic that this issue can be resolved so the mechanism can be modified. These plates have cogs that overlap the date ring partially, but in no place, on any of the plate is the date ring completely overlapped. This means that a little reengineering may solve the issue.

Here are the steps of modification I can imagine taking place

1) tap second plate into bridge on engine so it attaches above the mechanism via the bridge rather than the edge.

2) tap the first plate into appropriate parts of the second plate so again it does not need to attach at the edges of engine

3) grind the edges of each of these plates as far as is suitable to keep fit of cogs (only exposure of a circular area covering the outer few milimeters of the date ring is needed

4) add a appropriate spacer and new plastic date ring which thus bridges the two plates

thoughts....

thanks

Hi Guys,

I'd like to open by saying what a great forum this is. Lots of info.

I've been reading around about the Navitimer replicas and in the reviews the prevalent issue appears to be the drop out of the date number. This is a big deal to some I'm sure.

I was wondering if anybody has taken a good look at this to see if it can be modified to be raised to a more appropriate position?

Are there any pictures of the modified 7750 with the dial removed? This would help clarify what the problem is and how a little modification might be possible.

thanks