7s26 jewel orientation

[dreja]

Hello,

While working on my 7s26 I was watching the video "Conclusion Seiko 7S26 SKX Divers Service and Lubrication".

At about 6.34 Mark is mentioning to turn the jewel upside down.

https://www.youtube.com/watch?v=kHY_ysWq39o

It is necesary to put the jewel into place with the correct orientation (up / down) ?

If yes, how to know which part is upper and which is lower part of the jewel ?

 

Thanks

Andrej

 

 

[oli]

Yes definitely, otherwise you will not have the correct end shake, and the jewel will not retain the oil in the centre.

There is a concave and convex side, the pivot rests against the concave side.

Magnification will help you determine which side is which. Once you get used to it, it is very easy to see, the reflection of the light in the jewel is different for each side.

[jdm]

On 12/19/2017 at 9:54 AM, oli said:

There is a concave and convex side, the pivot rests against the concave side.

I think that the pivot side is actually flat, but I have no firm evidence about that.
Another way to determine the pivot side is to lay the stone on the mat, and very carefully touch the edge of the stone with tweezers or oiler. If the pivot side is up the stone will tend to rock (and potentially fly away), so don't do that without protection e.g. practicing in a small jar. Touching on the convex side the stone will tend to stay in place. 

[dreja]

Thanks for the answers

Andrej