Thursday, June 09, 2011

Marathon Modification Update 3

This is the final update as the watch is now complete. 

The ETA 2824-2 now fitted inside the watch. The metal spacer holds the movement in place. 


Another view of the ETA 2824-2 inside the Marathon JSAR. Note the lubricated gasket. 


I do have to admit that the movement does look small inside the huge 46.6 mm case.


The case back. Note the crinkle washer inside the case back. The crinkle washer helps to hold the metal movement spacer in place. Sadly the crinkle washer is not held in place inside the case back. This makes the installation of the case back a bit difficult as it (the washer) can fall out.


As highlighted yesterday, my friendly neighbourhood watch guy did not want to broach the sweep seconds hand. His reasoning is that the outer diameter of the sweep second hand body is .27 mm while the inside diameter is .20 mm. If he were to broach the sweep second hand to .25 mm (inside diameter), there would not be much metal left on the body. 

As such he suggested that he change the sweep second hand post. Looks like there are other ways to do the modification. Location of the hand post. 


The removed seconds hand post. With the modification done this way, I can always reverse the modification (if I need to). 


Another part which is not used. This ring is the spacer between the movement and the dial. 


The old date wheel (from the ETA 2824).


The old ISA 1198 movement. Before I forget, you will need to change the winding stem of the ETA 2824-2 as the standard winding stem is not long enough as the Marathon JSAR case is big. 



So as a recap, the things that needs to be done in the conversion:
  • Get a new movement, ETA 2824-2.
  • Get a new date wheel, if you want to have the same look as the original.
  • Option 1, broach the sweep seconds hand to .25 mm.
  • Option 2, change the sweep seconds hand post to .20 mm.
  • Get a longer winding stem for the ETA 2824-2.

The watch, completed. I am indeed happy with the conversion.

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