Weird jewels for Nivada N35 movement ?

[Flubber]

The jewels for the train bridge have cap jewels that is screwed on. However, what puzzles me is that the jewels where the wheels for the pivots seems to be upside down, that is the cup were the oil usually resides is on the underside of the bridge. Is this really correct ? How can you control end shake correctly ? 

[RichardHarris123]

The cap jewels are the correct way round.  A drop of oil is placed on them and then the plates are reinstalled. End shake should only be an issue if the cap jewels are displaced  

[mbwatch]

This is correct. Rather than the oil sitting in an oil sink on the top side of the hole jewel, the oil will be suspended between the flat side of the cap jewel and the convex side of the hole jewel. Place a tiny drop of oil on the flat side of the cap jewel and install it over the hole jewel which is unlubricated.

Don't put any lubrication in the concave underside of the hole jewels.

Image from wikipedia 

[Flubber]

Of course, the cap jewel will control the end shake ! Thank you for the quick replies.

[Nucejoe]

Just now, Flubber said:

Of course, the cap jewel will control the end shake ! Thank you for the quick replies.

 You sound overly concerned with end shakes in gear train, it can exceed .02 mm  which  is  fine as long as power get transferred from gear teeth and adjacent pinions with least resistance. 

End shake in the escapement matters.

As said no oil in the concave underside of the hole jewel, because the oil runs down and find its way to the hairspring. 

Rgds

[VWatchie]

4 hours ago, Nucejoe said:

You sound overly concerned with end shakes in gear train, it can exceed .02 mm

Indeed! I used to obsess over end-shake which only resulted in jerky energy transfer through the train. It's like shoe size—better a little too big than a little too small. In my experience, .02mm is too small, especially on cheap Vostok and Raketa movements.

Edited July 30, 2024 by VWatchie