Jump to content

Should this bridge be replaced? 7750


Giuseppe

Recommended Posts

Hi,

in order to buy appropriate spares in my attempt to service an Omega 175.0083 (7750)  I need some advice:

1.
I've already been suggested to replace MS:
Barrel is Ok and I'm thinking of buying a new MS and moebius 8217 for barrel lubricating as I don't want to spend money on recommended Kluber 125 grease.

Should I consider instead buying a barrel complete (assuming Barrel complete (180.1) comes with MS installed) wich supposedly comes prelubricated ?

2.
Attached image shows automatic device bridge with evident sign of wear from where, to my understanding, the problem orginated: a screw came off
I cant find original part. 
ETA part is different from Omega in that the Omega is larger and partially covers hammer two function and the chronograph cam.

Beside that and since the watch has no crystal back case I think those parts are perfectly interchangeable.

Do I need to replace the bridge or are there alternative aproaches to this problem?

TIA

Giuseppe

IMG_0013.jpg

IMG_0015.jpg

Link to comment
Share on other sites

What makes you suspect the bridge is faulty?  Afraid next screw will have the fate of previous one? What condition is the rest of the watch in. I personally am obssesive and wont let anything but the best get back in the movement, especially the iconic 7750,

Screws are to hold the bridge in place,  accurate positioning is the job for the pins. 

If you will please explain your question in more detail.

Regards joe.

 

Link to comment
Share on other sites

40 minutes ago, Nucejoe said:

What makes you suspect the bridge is faulty?  Afraid next screw will have the fate of previous one?

This is the reason why I'm asking if that sign of wear can compromise how the screw will stay in place.

Despite of those signs I see enough space for the screw to make pressure to the bridge and hold it in place.
And the slot on the lower bridge where the screw fits shows no sign of wear.

I lack in knowledge here and I'm definitely afraid that the screw might fall apart again.

To my eyes the rest of the movement is in perfect condition.

Thanks for answering!


 

Link to comment
Share on other sites

If just concerned about the screw falling off again, you can put a bit of glue on it ,which keeps it in place in slot, do not attempt overtightening the screw?

I see two chisel marks on both sides of the screw slot. You should check the other side of the bridge for effects of chisel impact. The bridge should be perfctly flat and in no way impede free transfer of power to barrel ratchet. 

No soldering,  just glue and watch out for glue seeping furthure to the movement.

So if it winds good it is doing it's job right.

Regards joe

  • Like 1
Link to comment
Share on other sites

Loctite has no place in there. Think of the watchmaker who next has to work on this, and bear in mind that may be you.

If the plate is flat and the screw holds it securely in the right place you should be fine.

If you really need to repair this, then the best way in my view would be to drill out the hole oversize and solder a brass bush into it.

Link to comment
Share on other sites

Fifty year old nail polish or color, when cleaned with acetone? shows no sign of chemical damage to the plate.

Use of heat only as one of last resort. Sorry stuart can,t agree with you, heat can warp the thin bridge plate instantly, The worst nail polish will do is slight surface discolloration.

I have seen nail polish used on hairspring collet and fifty years later no sign of damage is observable.

 

Link to comment
Share on other sites



  • Similar Content

  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • Have you ever seen grease spread?  I use Molykote DX on the keyless, cannon pinion, etc and cannot imagine it spreading. Similarly, HP1300 should not be a problem, as long as you don't splash too much about.  9010 does like to travel though. I've recently re-serviced a couple of my watches I first serviced about 5 years ago. I was a bit too liberal with the oil and grease back then, but it hasn't spread everywhere. I only epilame on balance cap stones, escape wheel and pallet stones (and auto wheels if they need it).   If you use it all over, the oil might bead-up and travel even further - think of using RainX on your car windows.
    • Polish it where the old part cracked as well. Get rid of the stress-raisers.
    • Sounds great! And yes, I would use grease for the keyless as well although treating the parts with epilame would make the grease less likely to spread in the long run. Not critical but won’t hurt. My current strategy is to epilame treat all parts getting in contact with oil or grease.
    • Hello everyone, for what it's worth, here is my approach: 1. Escape wheel submerged in Epilame, then dried quickly with a hairdryer. Then the final tip of the pivots are cleaned by poking into pithwood. The logic being that the Epilame is removed at the intended contact point (to avoid any residue that may mix with the oil), but remains in the areas where oil is not supposed to spread to (further down the pivot towards the wheel). The escape wheel teeth also benefit from having Epilame to keep the 9415 in place.  2. I use a syringe to treat only the pallet stones. I suspend the pallet fork with some Rodico so that the stones hang downwards. I notably use a rather thick needle where a drop WON'T form, but rather where the Epilame liquid stays in the needle tip, which I then dip into the pallet stones. It requires some practice to get the right amount of Epilame into the needle tip, but it works for me now. This way, no drop will "jump" onto the pallet fork and potentially go all the way to the pivots.  3. I let the movement run for a few minutes without lubricating the pallet stones... to scrape off the Epilame in the intended contact "channel". Then I remove the balance again and lubricate the exit pallet stone with 3-4 successive drops. See the "channel" that forms on the pallet stone in the picture -- not so easy to see, but it's visible.       I am conflicted about the use of Epliame in balance jewel settings. My impression is that the two jewels sufficiently suspend the oil (even 9010). Apparently Rolex recommends NOT to use Epliame there (heard from a former Rolex service center watchmaker), as it could cause additional wear. Apart from that, I follow specific instructions where I can find them. E.g. the infamous Rolex reverser wheels or sometimes (parts of) the seconds wheel. Exception: I'm currently servicing an Eta 2824 and will probably ignore the service sheet that recommends treating the whole keyless works with Epilame and then using HP1300... I'll skip the Epilame and use 9504 grease.        
    • I'm going to give this a try today/tomorrow on my UTC33/Seiko 66, thanks!
×
×
  • Create New...