Stuck Lens Diaphram

[Ronald Bishop]

My Chinon 55mm 1:1.7 lens won't stop down,  the blades aren't even showing--wide open.
    There isn't a mark on this lens, body or glass, like new. The threads still look new, no bright marks what so ever.
     Any suggestions on how to free them without taking it apart ? 
  Thanks
       Ron  B
   

[Glenn Thoreson]

Ron, the blades have oil on them. It's probably turned to goop by now. It has to be totally cleaned off for the blades to work. The only way that can be done is dismantlement. (Is that a word?) You could try setting it to f/16 and baking it in the sun to see if the glop will melt and let it stop down. Regardless, it would still require dismemberment. Those blades must be squeaky clean and dry, or no workie.  :mad:

[Ronald Bishop]

That is the answer I was afraid of Glenn, I sure won't be the one to mess things up.Besides I don't have the proper tools.                                                                                                                         Think I will call a couple of places in the morning for a price estiment.
    This camera is pretty much complete and really clean with a motor drive , 35 & 135 mm Chinon lenses, all like brand new.
      I plan on keeping the camera for a while, it is so simple and easy to operate, about like the Kodak Retina llF that I shot last weekend. Red to Green and shoot.
   

[LarryD]

Would it be cheaper if I sent you the lens for free with you paying shipping? I am pretty sure I have a few around here.

[Justin Smith]

I have a CZJ Tessar 50mm that was behaving the same way, except the blades would move somewhat. I took off the rear element and swabbed the rear of the aperture blades with lighter fluid and compressed cotton swabs until they were clean.

Worked OK for about a year, but I need to re-do it as the oil has migrated over them again and starting to gum them up.

[radiophoto]

The only way that can be done is dismantlement. (Is that a word?)

I think it's dismantle

[Ronald Bishop]

I tried the Ronson oil thing on an old Biotar off the Exakta, it worked to loosen them but ended up with oily blades.
    I don't have the proper peg spanner and besides my fingers and hands don't mind that well anymore. And the sun in the window thing won't happen this year?
    The camera case has a $49.99 tag on it so don't know if I want to spend more on it or not?
    I think I have a Yashica 50mm  and a Sears 28mm to use on it so I guess the Chinon 55 mm is heading to the back of a drawer if the estimate is too much.

[Glenn Thoreson]

Ron, unless there is some emotional tie to that lens, it's not worth having it repaired. They only sell for 10 or 15 bucks and there's plenty of them out there. I may have one. I'll take a peek into the camera closet from hell.

[Ronald Bishop]

I know they are worth less than the shipping cost but this lens is so clean, inside and out that I hate to deep-six it.
      I may just make a spanner to remove the eliments and see if I can free them up,it will be good practice for me this winter during a snow day :cool:
    I the 28,50 amd a tele and a couple of doubles so if I decide to put film in it I won't want for a lens.
    Besides I found a new toy today !

 And thank you everyone for the free offers ,but please, Momma says I don't need anymore camera 'stuff' . Her words, not mine, and she is the boss ------ya, surrrre.