Omega 565 rotor bearing

[Ascanio]

Hi!

This is my first post just after the quick introduction one .

I did purchase an Omega 565 movement but I have noticed the rotor is touching the watch in its round moves. I did conclude (!) the rotor axale is a bit bent so I decided to purchase a spare part 550.1400 (Rotor Axale) and replaced it. Surprisingly the rotor now fits very very tight and it's very hard to rotate (it would never turn by gravity alone).

I did read that the rotor axale 550.1400 and the pinion in the rotor need to be broached/mated, but I did not expect a new axale and an used (and possibly worn out) pinion would match so tight to not to move.

Question: do I really have to broach the pinion of the rotor so it can move freely? And can I do it with a manual broaches without a staking tool (which I did not purchase yet...)? I am a bit scared as still I did not fully understand what prevents the rotor to fall off the axale, I suspect it's the gib 550.1451 but it is not clear from the exploded view at page 10 of manual of calibre 551 which I use for reference...

Thank you!!

Ascanio

[watchweasol]

Hi Ascanio   part 550.1451 is indeed the locking for the rotor, remove the screw and lift off the rotor removing the lock as you do so .   I should put back the old axle and re fit the rotor and check for freedom again. number 550.1400 is the axle. I have attached the tech sheet for the 565 just in case there are different Numbers although all 500 series are usually common.  The  only thing  that could have bent the axle is its had a knock.  You could try straightening the old axle using a pin vise over it and gently reforming it checking the clearance as you go but be gentle.

377_Omega 565 NewLR.pdf

[Ascanio]

Hi Watchweasol and thank you for your suggestion.

I will try what you propose when I will get back to my bench in a week or so. I am afraid current axale + rotor pinion is anyhow a bit loose and there is quite some play, so ideally I did not dislike the idea of a tighter fit, so if trying to straight the old axale will not  provide good result I will be back to the idea to broach the hole (pinion?) of the rotor. Is this advisable to do it by hand without a staking tool? Now that I better understand the role of the 550.1451 locking, i woudl assume it is safe enough...

Thanks again, nice to be in this forum

Ascanio

 

[watchweasol]

Hi Ascanio    Broaching by hand is permisable  remember a broach is tapered therefore cut from both sides to achieve a parallel cut the secret to work slowly with frequent checking of the fit. polish the finished hole with a sooth broach or use pegwood. 

[JohnR725]

if you read the technical document found above you'll notice on page 3 there is reference to another document? This is the document you need which explains how to fix the problem of the new weight becoming stuck if it's not properly adjusted. The only problem is you're not going to have the tools. But in the absence of lacking of the proper tools I'm extracting out the text that you will find interesting

"The new oscillating weight becomes stuck if it is not adjusted to the stud (pin). The new studs designed for the oscillating weight in the calibre 550 family are 0.698 to 0.701 mm in diameter."

The reamer is described as "Hard metal precision reamer Diameter 0,702 mm Reference 516 0072" then even if you can find the reamer you need the spindle that holds it in the staking set. So what we get out of this is the axle is over size and you need to open the hole to 0,702 mm. I would suggest not using the old parts just replace both of them. then if you're careful you can use watchweasol instructions with a brooch which will work just be careful it's easy to go too far.

 

[Ascanio]

Thank you for all precious information!

I feel now fully equipped to bring this lovely movement back into a case!  I can't wait to be back at my bench in one week from now  I'll post the progress.

Happy Easter everyone!

Ascanio

[Ascanio]

All worked out very smooth! Broaching was indeed very very light operation! I imagined to have done nothing instead it made an impressive difference just at the first fitting test!

Actually I found out the rotor was very stable but still touching on the bottom tip, so I thought it was also bent, so I put it on an anvil and gently hammered it flat. Most likely the movement was damaged by a fall or something, and was bent both the stud and the rotor. 

Now problem fixed! The rotor is now very solid and not touching, no metal noise while revolving.

I'm very happy and satisfied with the result.

I could not find the pointed side document indicated by John searching online, it would be an interesting reading for me as I am try to focus on these lovely movements. Maybe is kind of a reserved document available only to Omega trained watchmakers?

Again thanks for the very insightful suggestions, I learned a lot and I will make good use of this knowledge.

Ascanio