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I was searching the web for some information last week and came across a thread in which one of our members (Sir Alan) mentioned he had a broken "shroud" screw in his 7A28-7000 Alien case, so I contacted him and asked if he had removed it, if not would he like me to have a try for him (stuck my nose in but.....:) ).

Well Sir Alan (Simon) replied it was still broke in his case and if i fancied having a go at removing it then he would bring it to the Birmingham watch fair which he did.

So today I set about removing it and bearing in mind that the alien is the black coated version so i did not want to damage/mark the case in anyway.

How it went:

  • First off i made a Acetal clamp/washer to fit inside the case and clamp on the crystal sealing face.
  • Next I went for a proper holding fixture that the case would slide over holding it true with minimal contact and seat against the gasket sealing face on the rear of the case.
  • Then mounted the fixture vertically on my rotary table and lined the good hole up.
  • Once the good hole was a known position then it was pretty easy to line the hole up with the broken screw in it.
  • Rough machined through the broken screw first with a 1mm cutter and then a 1.5mm cutter (safer and truer than drilling).
  • Finally used the screw extractor to remove the remaining broken thread which showed evidence of some form of loctite.
  • All done and the original thread is like new and untouched :)
Good result (imo) and the case is good to go :)

















 

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Wish I could do this to dads Omega Constellation Automatic. Case has one mangled screw probably caused by the last place that serviced it.
 

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And this is why the world is a good place to be (on the whole).

What should have been a simple operation (remove the pusher shroud to fit new plastic pushers) turned into a nightmare when I underestimated the amount of force required to undo the screws and picked the wrong size screwdriver. (I do partly blame Seiko for the thread lok they use).

I managed to drill the head off the screw without damaging the pusher shroud (no mean feat considering my lack of tools) but realised that I could not drill out the screw without damaging and thus ruining the NOS case. Something I couldn't bring myself to attempt.

So, the case was consigned to the spares bin for another day.

Now, not only have I got a fully functional case, but I have met John. And the virtuous circle continues .....................

(more to follow when I have re-built the watch).
 

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Well done John. There would be a line out to the street if you could do the same to a broken stem and save hard to find crowns. Hint , Hint.
 

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Very nice John :cool:. As someone who started his working life with a 5 year apprenticeship as a scientific instrument technician, I really miss not having access, any more since retirement, to the sort of engineering tooling that you have, very jealous :(
 

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Well done John. There would be a line out to the street if you could do the same to a broken stem and save hard to find crowns. Hint , Hint.
Removing a shroud screw (2mm) is heavy engineering Mike so pretty "easy" but removing a broken stem is hard work imo and i havent the kit for it (watchmakers lathe), if i had a watch makers lathe then it would be possible (i think :) ).
 
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