Jump to content

omega 920 winding stem


gary17

Recommended Posts

Time for me to go hide myself.especially if gary is a boxer.  

The hole in sliding pinion is couple of mm deep, too much material there to be removed by alum.

I rinse, mount sliding pinion on a stem vice, spread sand paper on flat glass, drag the winding pinion side on sand paper( stem vice prependicular to flat surface) to remove material from stem and part of winding pinion, this weakens its strucutre, remove by braking the crown in pieces. 

Re-soak the sliding pinion, couple of days, plenty of light taps on the stem. Easy dose it. Mr boxer.

 

Edited by Nucejoe
Remove winding crown by breaking in pieces
Link to comment
Share on other sites

4 hours ago, gary17 said:

Hey

Is the crown wheell also called the winding pinion?

gary

No, crown wheel sits on barrel  bridge and mesh with ratchet gears.

Eternaltools.com names parts on an illustrated glossary of parts according to ETA.

Best 

Link to comment
Share on other sites

10 hours ago, Nucejoe said:

No, crown wheel sits on barrel  bridge and mesh with ratchet gears.

Eternaltools.com names parts on an illustrated glossary of parts according to ETA.

Best 

Oops my mistake.  Ignor my previouz post.

Link to comment
Share on other sites

This is a very solid movement, so 99.999% sure nothing shifted. If all's free up to the escape wheel good chance theres a hair or whatever under the cock causing it to tilt and clamp down. Or maybe an escape wheel pivot is bent/rusted/damaged.

 

 

 

 

  • Thanks 1
Link to comment
Share on other sites

Hi Gary  If doing all that has been advised the escape wheel is still tight remove all other wheels and fit the escape wheel on its own after checking that the pivots are dot damaged or bent that way there is no interaction with any other part only with the part you have issue with and it should be easier to track the fault. One thing check the seating where the escape wheel bridge sits for dings or delves, these were some times used to alter the height of plates ad bridges.

Link to comment
Share on other sites

Yer

The escapement wheel is not damaged. The escapement pivot will not fit into jewel in escapement Bridge. It's fine until you tighten then the hole in the jewel holds the pivot to tight. 

Try and work out what my next step is. 

Cheers gary

Link to comment
Share on other sites

If fork pivot dosn,t get into its jewel,  perhaps wrong fork or wrong jewel.

If it dose get in, but fork gets stuck as you tighten bridge screw, you need to adjust fork jewels.

Jewel adjustment should bring pallets to level with escape wheel for proper pallet- teeth interface. 

Gentle champ :judge:.  

Link to comment
Share on other sites

Pallets and escape teeth should level, geometricaly in one plane.

If the lower fork pivot gets in lower jewel hole ( hole on the mainplate), chances are the jewel in fork bridge is a wrong one.

Fork bridge may have been shimed which got washed away and you didn,t notice, wrong arbor fitted on right fork, wrong arbor& fork, wrong jewel.

 

 

Link to comment
Share on other sites

Yer 

i have stripped the plate and started again with just the escapement wheel and bridge.

That seems to work perfectly. (see pic)

I will now add the train wheels 1 by 1 and try after i add 1 to make sure its free and see were i get to.

gary

 

IMG_20191005_173610.jpg

Link to comment
Share on other sites

Yer 

Every thing works fine until i put the escapement bridge on.

But once you centre the escapement pivot to fit in the jewel hole it dont work.

So i guess i need either to make the jewel hole bigger or the pivot smaller.

gary

I have everything lined up perfectly.

If i turn the centre wheel it don,t move but if i turn the escapement wheel all the train wheels turn including the centre wheel.

This cannot be correct surely?

Edited by gary17
Link to comment
Share on other sites

1 hour ago, gary17 said:

Yer 

Every thing works fine until i put the escapement bridge on.

But once you centre the escapement pivot to fit in the jewel hole it dont work.

So i guess i need either to make the jewel hole bigger or the pivot smaller.

gary

I have everything lined up perfectly.

If i turn the centre wheel it don,t move but if i turn the escapement wheel all the train wheels turn including the centre wheel.

This cannot be correct surely?

:o:rolleyes:   

Link to comment
Share on other sites




  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • Two pins or screwdrivers angled out slightly, pressing through from the barrel centre from the opposite side so they contact just clear of the hole in the lid? eg. Strap pin driver needles or similar.
    • That's a good idea - shrinking down the nut and wrench size from the old casebook trick!
    • I missed this earlier. The dial isn't going into the holder, it should sit proud of it. This is what I am currently using which I print for each different movement.    
    • I didn't think pulling to set position would work harden the spring, in that position it is stressed where the arm starts. By work hardening i meant rapid polishing at that point, a bit like polishing a pivot work hardens as it compresses the steel. I doubt polishing by hand would achieve much in that respect though. Its finished, arm polished up mostly at the join to the bridge's main body. I'm ok with it, the screw holes aren't great as i had to open them up by redrilling and positioning it was difficult, I'm not much use with a loupe, opening up with a file might be a better option for me or i could just use the correct drill size 😅. And the detent is way too deep, i had to guess that with the stem release out of position and sat on top, but i only took one measure and went for it, no slowly slowly catch your monkey 😅. First go I'm happy , well sort of, it works and thats a big thing for me, next one will have a bit more finesse.  Anyone thats interested, after filing, i used a 2000 grade home made diamond  micro file and then 20 micron film, the film is much better than wet and dry, more stable to use and doesn't shed cheap grade grit everywhere , then auto polish on a sponge pad.
    • I'm assuming that every time you set the watch you are work hardening the detent spring, maximum hardening is  where it meets the plate due to maximum deflection.   That's why it snaps there.  The Young's modulus may be the same but after it's reached its maximum yeid strength it breaks.  My mechanic engineering is very rusty, correct me if I'm wrong. 
×
×
  • Create New...