Jump to content

Recommended Posts

Posted

I rarely work on pocket watches, but fell in love with the hands on this, and got it quite cheaply.  I have seen a couple of other pictures of 19 ligne omega movements with this different bridge design, but no discussion of why, or which variant. I haven't included pictures of the dial side, but it looks just like other 19s.

I need a new mainspring, but the GR catalogue lists many spring types for the Omega 19; none of which quite lines up with what I found fitted. For a start the barrel ID is 16.5mm which doesn't appear on any of the options.

The old spring just had a standard riveted hook bridle, but the barrel has slots which look like they would take a "DBH" bridle.  I've never bought one of those, but it strikes me that the distance between the hook end and the T piece must be exact for it it fit correctly.

The old spring is 0.19mm thick and 2.6 high. The barrel is 16.5 ID & 3.2 deep, and the barrel arbour 5.3 OD.  Theory says the old spring is the right height and thickness. I haven't tried to measure the length, but theory says this should be around 500mm.

There is a letter M stamped on my barrel bridge.  The catalogue lists a 19M with 2.6 x 0.2 x 560 x 17.5 and DBH bridle.  Height and width are good, but the barrel diameter and length are too big!

I will probably just get the nearest size standard hook spring I can find, but if anyone knows more that would be interesting...
 

image.jpeg

image.jpeg

image.jpeg

Posted

A day older and (just) a little wiser.  Omega sold movements into the US market under the brand "Regina", these shared common parts with their other movements but had different bridge designs, it appears they also sometimes sold these movements under the Omega brand just to confuse the unwary.  This doesn't help me much, but for those who speak French, here is a very similar example and some other wonderful information (if you don't speak French, at least look at the table of hand styles in the second link!)

http://forumamontres.forumactif.com/t17823-regina-c-est-beau-c-est-tres-beau?highlight=Regina

https://sites.google.com/site/hourconquest/oomega

Cousins has springs which are close enough to the right size in either standard or DBH fitting. Should I have a DBH Spring in this barrel? Note there is a corresponding long slot in the barrel cap to match the one shown above in the barrel as well as another slot in the cap which will line up with the hook in the barrel wall.

S

  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • A helpful way in aid of assembly is to place all the wheels in their respective places, place to plate on the top and fit a couple of the nuts onto the pillars. This stops all the wheels wobbling about as they are lightly held by the plate, you can manoeuvre the pivots into their holes, using a tool , usually home made or can be bought on eBay. I made my own. As the pivots align and fall into place screw the nuts down a bit to keep up the tension on the plate untill all wheels are in place then tighten down sufficiently to keep the plate in place whilst checking the end shake on ALL wheels and their location when all is good only then tighten down the plate.
    • I'd say my Pultra 10 lathe. It is just so well made and everything fits so tightly together.
    • Welcome to the forum, enjoy. 
    • Yes, the specific old tools do exist, but may be having one is not needed as they are not cheap, and also You will be able to do without it well enough. My advice will be to use regular depthing tool and adjust it for the exact distance between pallet fork and escape wheel bearings from the watch. Then remove the shellac from the pallet that now doesn't pass the ew teeth and move this pallet in. Then put the pallet fork and ew on the depthing tool and check how they lock. They should not lock when the pallet is in, but You will little by little move the pallet out and locking will appear. Then move just an idea out for reliable work and apply shellac, then check if things are still the same. You have to observe where the teeth fall on the pallets - it must be just a little below the edge between impulse and rest planes. Then You must check how everything behaves in the movement This Potence tool is so ingenious, but actually, the traditional way to do the things is much more simple. Arrange the parts not on the pillar plate, but on the cover plate. Only the central wheel will remain on the pillar plate, secured by the cannon pinion.
    • There is a tool that was made for setting up and adjusting escapements of full plate watches.  There were two styles, the picture below shows both of them.  The lower tool held a movement plate and the vertical pointed rods were adjusted to hold the unsupported pivots of the lever and escape wheel.  There was also a version of this tool that had 3 adjustable safety centres so that the balance pivot could be supported by the tool :  The other version I’m aware of is the Boynton’s Escapement Matching and Examining Tool came as a set of two or three clamps that gripped the watch plate and held the safety centres for the pivots : These do turn up on eBay from time to time.  For some escapement work, you can set up the parts in a regular depthing tool, with the centres set according to the distance between the corresponding pivot holes on the movement.  I hope this helps, Mark
×
×
  • Create New...