Base movement assembly

Now all the parts have been reviewed and brought back to specification, where required, the basic movement can be assembled.  From this point, the main checks are side shake (lateral clearance in the jewels/bushes) and end shake (longitudinal clearance in the jewels/bushes) – adjustments are made as required.

The barrel bridge is temporarily fitted and then the keyless works installed on the dial side.  These interact with the crown to wind the movement and adjust the time.

Omega Seamaster 30 repair and service - keyless works installed

After checking the mainspring, I decide to re-use it as the customer recently paid another watchmaker to replace this and service the watch.  It is wound into the mainspring winder.

Omega Seamaster 30 repair and service - mainspring in winder

Then pressed back into the barrel and the barrel closed with the barrel closing tool.  The end shake of the arbor in the barrel can be checked here and adjusted if required.

Omega Seamaster 30 repair and service - barrel closing tool

With the movement turned over, the barrel and centre wheel are installed.

Omega Seamaster 30 repair and service - barrel and centre wheel installed

Then the crown wheel that transfers the rotation from the crown to wind the barrel.

Omega Seamaster 30 repair and service - crown wheel fitted

That’s accomplished by the ratchet wheel and click/spring, now fitted.

Omega Seamaster 30 repair and service - ratchet wheel fitted

After a special treatment on the escape wheel, the remainder of the train is fitted.

Omega Seamaster 30 repair and service - train fitted

And then the pallet fork with its special treatment on the jewels.

Omega Seamaster 30 repair and service - pallet fork fitted

And finally, the balance is re-fitted – the base movement now runs.

Omega Seamaster 30 repair and service - balance wheel refitted

This is allowed to run for 15 minutes and then the pallet jewels that interact with the escape wheel are greased with a special grease and any small adjustments are made over the following two days.

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