7750 Top Jewels Damaged - how do i go about finding replacements

[jnash]

I have a 7750 that must of taken some type of damage and it has left the 201 and 210 wheel (Great wheel and third wheel)

The top jewels are in pieces, im assuming they are press fit, but how do i go about finding replacements and getting the correct sizes?

 

Thanks

in advance. 

[AndyGSi]

I think you'll just have to get a new bridge.

[nevenbekriev]

Well, jewels can be replaced, especially the pressed in ones. You need just to determine the sizes and source such jewels. Having many and different useless movements and bridges is useful for taking stones, springs, screws and other needed parts out of them.

[Nucejoe]

Is this an ETA 7750 ?   Valjoux made 7750 . Show an image. 

I don't know what parts interchange, if not all.

 Go on to Julesborel.com , they might list some in stock. Then theres cousins UK and many other material houses , ebay too, google brings you a list of suppliers, so will our good member watchweasel.

Good luck

 

 

[caseback]

There is a Dutch expression that says "meten is weten". The 1:1 translation is "measuring is knowing". Do you have or have access to tools like a micrometer and a Seitz jewelling set?

[AndyGSi]

@nevenbekriev & @Nucejoe So what type of jewels would @jnash be looking for to replace the broken ones?

[Nucejoe]

 Google brings you many pdf for 7750  and list of parts suppliers.

Is your movement ETA or Valjoux make?

 I have an original Valjoux 7750 , seen image of  7750 made with slight variation is jewel and shock system.

Show pix please.

Theres a super walkthrough by Lawson  on ETA 7750 in WRT  see if its  the same as your movement.

 

Edited October 2, 2024 by Nucejoe
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[AndyGSi]

1 hour ago, Nucejoe said:

Google brings you many pdf for 7750  and list of parts suppliers.

The problem is that the bridge jewels aren't listed as replaceable parts.

I think these are the jewels they're looking to replace.

[Feedback]

Are the jewels in question "cracked but intact," still in the bridge? If so you can try to measure them in place before you push them out (at which point they will likely end up in small pieces). One way to do this, if you have a microscope which can take photos, is to photograph the jewels at high magnification next to a microscope calibration slide. You can then use software (I use XCap) to get a fairly precise estimate of the inner and outer diameters. 

If the jewels are already destroyed you will have to measure the bridge hole diameter and corresponding pivot diameter from the wheel, keeping in mind that the outer diameters and hole diameter of the appropriate jewel will be slightly larger than these values. 

You can then order replacements online (I find JulesBorel is a good source that stocks most sizes). As with crystals you may consider ordering a few different sizes to help ensure you're getting something that will work.

 

Good luck!

[Nucejoe]

Yep, replacing with a new bridge ( just checked prices on julesborel)  wouldn't break the bank 

 Calib designation on my movement is  VAL 7750,   came in  Omega as I remember with calib 1155 designation ,  there prices were scarey high.

 

 

 

 

[jnash]

thank you all , since writing i found a donor replacement plate in my parts and took the jewels from there, would usually just switch the plate but its decorated with a exhibition back.

Thanks for the help, good to know for next time.  

[AndyGSi]

1 hour ago, jnash said:

thank you all , since writing i found a donor replacement plate in my parts and took the jewels from there, would usually just switch the plate but its decorated with a exhibition back.

Thanks for the help, good to know for next time.  

For reference and if other people come across this thread can you confirm type and size of jewels?