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Help with Zuiko 50mm 1.8 disassembly
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PostPosted: Tue Jan 16, 2018 11:00 pm    Post subject: Help with Zuiko 50mm 1.8 disassembly Reply with quote

Greetings! Although I have been reading many of the threads for a long time on this forum, this is my first post, so thank you already for all the wisdom and ideas, and of course the photographs!

I hope someone here can help me with this problem:

I have a Zuiko 50mm 1.8 with a sticky aperture. This seems to be the version of the Zuiko 50 1.8 that is prone to the sticky aperture! However, it doesn't seem to be quite the same version that Matt Bierner has the YouTube video for (https://www.youtube.com/watch?v=aj0S55-aXjQ).

I want to be able to clean the diaphragm ring with lighter fluid, but can't do that until the lens elements have all been removed. (I think the aperture stickiness is due to oil between helicoid assembly and the rotating plate that the iris blades sit on, rather than oil on the blades themselves.)

I can remove the front lens group with no problem to get access to the aperture blades (this group seems to be in a single sealed unit), but I can't get the all of the rear group out. I can remove the first black ring on the rear group, and remove the first lens of that group, but then there seems to be a spacer ring that won't budge, and that prevents me from removing the remaining lens element. Does anyone know how to remove this spacer ring, or that entire protruding metal part that contains it?

The olympus.dementix.org/Hardware website seems to be dead, but you can access it using the 'way back machine':

From the PDF, I think my version is on the third page, MS5018 Type-3 (MC), and the parts I'm stuck on are CE101300 and ZC195900, from what I can tell.

It seems as if CE101300 should unscrew (with ZC195900 retained inside it), but I can't budge it. Should I just use more force, or is there a trick to it? Help!!!!

Also, apologies if this seems like a very simple question - this is my first attempt at lens disassembly - I thought the Zuiko 50 1.8 would be a good one to learn on Smile

PostPosted: Wed Jan 17, 2018 11:28 pm    Post subject: Reply with quote

Almost invariably, rear group on vintage 50's comes of as one piece. Most likely you came across one of the Zuikos where they went nuts with thread locker.

PostPosted: Thu Jan 18, 2018 5:50 pm    Post subject: Reply with quote

@Gardener: Thank you! So I guess I should just eat my spinach and grow some Popeye muscles to unscrew it Wink

Success today cleaning fungus from a Super-Takumar 50mm f1.4 and a Jupiter-9 85mm f2 - both were very easy to entirely disassemble, and both are now lovely and clean, I think! They've been sitting on the shelf far too long, waiting for me to learn how to take lenses apart. Very satisfying!!

PostPosted: Mon Jan 22, 2018 12:00 am    Post subject: Reply with quote

o.k., so that worked, that rear group just needed an extra bit of force to come off, and off it came. cleaned all aperture parts and blades with a little lighter fluid on a cotton bud, put it back together, and now it's all working as it should Smile

PostPosted: Mon Jan 22, 2018 6:23 am    Post subject: Reply with quote

Congrats Whoo Turtle

Nice work! Thanks for documenting it so well here!