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Screws on Cyma 56 with a twist

Orologi67
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Orologi67 Watch Enthusiast

Orologi67

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I bought a really fun Cyma Synchron watch and had it shipped from Israel.  The gold plated case is pretty large and thick to be an early 1970s watch.  It needed a new mainspring which the best i could find was from Cousins.  Im on the southwest side of the USA. Did anyone know Cousins makes one do a bank wire transfer if the international order is over 1000 pounds??

Anyway.... so i decided to put the watch back together as a trial run after i washed it.  So i could free up the dust cover tray and not lose parts.  No lube.  No mainspring.  Just so i could assess faults and get a feel for the way it goes together, as well.

I believe this Cyma watch has an ETA 2770 movement but i cannot confirm positively.  Its some type of early 70's ETA.

So everything was just falling into place on reassembly but i got very frustrated with the screw lengths.  I'd say 99% of the screws in this watch are the same thread and same OD with countersunk head profiles, however they are 2 different lengths, and a few have polished heads but most dont.

It seems to me that simplicity is an art in and of itself.  Why didnt the technical designers make all the screws of the main size the same length to save time and frustration?

I thought surely the longer screws were for the bridges but they arent.  Those screws are too long because the length interferes with the date wheel on the dial side.

So heres the really wacky part.  I found a cap jewel apon disassembly that was laying in the movement.  Its not one of the balance jewels,  both are present in their respective incablocs  So a previous workman left one in the movement by accident.  I have this vision of a cap jewel pinging off a workperson's tweezers and he/she looked and looked.  Probably had to order a new one if they didnt have it in house.  And all this time it pinged over to this Cyma and was hidden in the case for years.  These little parts have a life of their own.  

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Orologi67 Watch Enthusiast

Orologi67

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Thank you watchweasol.  Where did you find that spec sheet?  Wow great information and it specifys where all the screws are designed to go.  Lovely!  And yes it appears to be an ETA 2770 mainspring barrel specs are the same 11mm inside diameter with a 2mm diameter mainspring arbor.  Here is a pic. 

20200725_140137.jpg

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