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Microrotor brass bearing replacement

  1. Diabolik Dec 26, 2020

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    Following a couple of attempts, I have designed a fix for the newer microtor bearings that are so prone to failure. The new bearing is made of brass and is tapered so glides over the tapered base of the microrotor pinion. Everything fits snugly with hardly any play and when tested, rotated with very very well ...

    upload_2020-12-26_15-27-46.png

    Thoughts ?
     
  2. CafeRacer Dec 29, 2020

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    If it works and its cheaper than sourcing a new UG bearing, then it sounds fantastic to me! :)
     
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  3. WhereMadnessLies Jan 2, 2021

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    This could be quite useful to a lot of us Polerouter enthusiasts. Would each new brass bearing have to be made specifically for an individual movement (as the wear levels will be different on every movement) or would just a "standard" part work?

    I have a cal 1-69 that I believe would benefit from this sort of fix so I'm quite excited to see how this develops.
     
  4. Diabolik Jan 6, 2021

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    You are right. There are a multitude of possible failures and maybe there's a more elegant way to sort this one out. The 5 roler bearings can be replaced, it is just a mater of finding the micro ball bearings or something that is similar in size. The roler bearing surfaces (bearing surface A and B) need to be refaced as they are usually damaged (not hardened steel) and rotor re-assembled ..

    upload_2021-1-6_17-21-53.png
     
  5. Ted1858 Jan 6, 2021

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    Just for my knowledge - is there a particular microtor movement that this type of issue is seen in (cal 69)? Or is it all of the microtor movements?
     
  6. CafeRacer Jan 7, 2021

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    Mostly caliber 68/69/1-69 has this specific issue with the bearing, the earlier 215/218 based rotors used a different system (but ultimately suffered from the same problem of wear).
     
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  7. Weihao Jan 7, 2021

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    My Polerouter with 215/218 movement has a soft metal friction sound when I shake the watch. Does that mean that it is now suffering from this issue? I did ask a watchmaker about it and he said it was perfectly normal.
     
  8. CafeRacer Jan 8, 2021

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    Impossible to diagnose confidently without having the watch in the hand unfortunately.
     
  9. Weihao Jan 8, 2021

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    Thanks. Looks like time for a service...
     
  10. Diabolik Jan 10, 2021

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    Well, refacing and using a brass bearing works. Not sure how long it would last. That is the next thing to test. The microrotor pinion become quite rough over time (see image) so need to be re-faced (faces marked in red) ...

    Bearing in blue ...

    upload_2021-1-10_21-14-23.png

    Microrotor Pinion
    upload_2021-1-10_21-10-5.png

    Brass bearing
    upload_2021-1-10_21-18-55.png

    Just a matter of re-assembling the movement and it'll be ready for testing ...

    upload_2021-1-10_21-12-1.png

    PS: I am looking for some old worn out bearings to try out if anyone has anything, PM me.
     
    upload_2021-1-10_21-13-37.png
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  11. PiePanPark May 19, 2022

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    Diabolik. THank you for the post. I have the same issue on a cal 69 with slop in the oscilating weight bearing. There are no 0.5mm thick bearings to purchase commercially. WIll need to use your brass bushing repair. Where did you source the bushing? Is it just friction fitted? some insights will help me immensely.

    TIA
     
  12. Dan S May 19, 2022

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    [​IMG]
     
  13. PiePanPark May 19, 2022

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    That's a nice watchmakers lathe, but it doesnt answer my question.
     
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  14. Dan S May 19, 2022

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    i suspect that it does.
     
  15. PiePanPark May 19, 2022

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    if so, what is the inner and outer diameter of the bushing? How thick is it? Where was it sourced? :^/
     
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