Nikkor-P 10.5cm F2.5 Oily Aperture

[gullosaurus]

Hello to everyone,

I have recently obtained a Nikkor-P 10.5cm F2.5 (Serial in the 133k range) BUT the aperture blades are coated in oil and stick in the wide open state - if I manually push the aperture lever the blades close but they don't have any snap at all.

I was wondering if anyone else has suffered this problem and whether or not a clean and re-lube will solve it - or if its likely there is another problem deep within (broken aperture spring perhaps ?).

I guess I won't know until I disassemble...

Any help appreciated !!!

Rod

[longzoom]

Unscrew the lens mount block. Remove it. Unscrew the back element set - at whole, I mean, do not open it! - it isn't excessively tight.  Submerge the aperture block into any alcohol, but do not remove it! Be careful, do not submerge the last optical element, alcohol must cover the blades only!  Let it dry, check the aperture manually. Must work as new! Clean the last inner optical element, if needed. Put everything back. Good luck!   LZ

[richardHaw]

this is kind of common for this lens 

in fact, somebody sent me with one recently

i am going to make an article on how to clean one soon.

[gullosaurus]

Thanks for the response guys, followed your instructions sort of LZ and dipped the aperture end into isopropyl alc success ! However upon reassembly I am now not able to focus to infinity, by about an eighth turn of the helicoid ... I guess I'll have to redo until I get it right ... can I remove the lens block ? I guess it's unsctrwable somehow. At the moment I'm just screwing the helicoids in and it's hit or miss if the aperture screw and pin engages which isn't ideal .... thanks again

[richardHaw]

oh my Buddha, you did what!? 

[longzoom]

Thanks for the response guys, followed your instructions sort of LZ and dipped the aperture end into isopropyl alc success ! However upon reassembly I am now not able to focus to infinity, by about an eighth turn of the helicoid ... I guess I'll have to redo until I get it right ... can I remove the lens block ? I guess it's unsctrwable somehow. At the moment I'm just screwing the helicoids in and it's hit or miss if the aperture screw and pin engages which isn't ideal .... thanks again

It is good you removed oil, but i did not say there was any need to touch the helicoid. You should find any small canister of appropriate diameter to submerge the inner tube with open aperture block ONLY! Just find right position for helicoid, not a big deal. In any case, do not remove or open the aperture block, becouse the blades pins in this old model could be lost at ease, do not even touch! Good luck!   LZ

[richardHaw]

hold on, I will publish something for you privately

check your private message!!!

[longzoom]

hold on, I will publish something for you privately

check your private message!!!

  Why privately? Everybody will be interesting in, i am first, if you show any different easy way to fix it, why not? THX!  LZ

[richardHaw]

Still in beta. Scheduled for next weekend!

[gullosaurus]

YES after a bit of trial and error 100% good as New, thanks so much LZ and Richard . Worth the hours to fix is a lovely lens alright.

Thanks again guys really awesome help.

Rod

[longzoom]

Gosh! You made my day, Rod! So next time its gonna take you 15-20 mins to clean the lens! Congs and best wishes!  LZ

[richardHaw]

good, at least all went well