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Message |
    
Gizzzmo
Tinkerer
Username: Gizzzmo
Post Number: 1
Registered: 10-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 20, 2007 - 07:15 am: | 
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Hi, i've just bought a Flektogon 35 f2.4 but the diaphragm doesn't shut. On the attached file you could see the mechanism which command the diaphragm (circled in red). It should automaticcaly move according to the red arrow (using a coil) in order to shut the diaphragm but this mechanism is not flowing. Moreover, i see marks on the diaphragm (see attachment). What are these marks ? Do you have any solutions ?
Thanks.
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Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 413
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 21, 2007 - 04:26 pm: |
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I don't see the picture showing the marks on the diaphragm ... generally, if the blades stick it's because they have oil on them. This is usually visible, but in some cases it's in the actuating ring or somewhere that you don't see it through the lens. In either case, my first guess would be to clean the diaphragm. |
Alex
Tinkerer
Username: Alex
Post Number: 43
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 22, 2007 - 02:49 am: |
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I have had exactly this problem with similar CZJ lenses, and as Rick remarks, the problem was due to oil migration causing 'stiction' of the diaphragm blades, and not, as I'd first thought, a weakened spring. I had to clean the blades thoroughly, which is not particularly difficult. The indication to me that this was the problem was when I put a couple of drops of lighter fuel on the blades. Seconds later, they snapped into position, then as the naptha evaporated, the 'stiction' re-appeared. Lots of grease, mixed with what looked like very fine metal dust, had been migrating from the focusing threads, so at the same time as I cleaned the diaphragm, I took the opportunity to thoroughly clean the helicoids and re-lube them lightly with silicone grease. Took about two hours, though I was proceeding slowly as I'm a tinkerer, not a technician. |
Gizzzmo
Tinkerer
Username: Gizzzmo
Post Number: 2
Registered: 10-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 03, 2007 - 02:20 pm: |
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I have cleaned the blades with "F" fuel (few drops and coton), it's better but not perfect. Aperture closes from 2.4 to 5.6 but not more. Can I drop the whole the aperture mechanism (just diaphragm) into "F" fuel (i've seen this in a tutorial) ?
Thanks. |
Aka
Tinkerer
Username: Aka
Post Number: 3
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 09, 2007 - 06:47 am: |
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Hi,
I've tried a number of cleaners and the best that worked for me was water with detergent. Just rinse inside a container the whole mechanism, activate the springs until it works free and works free as well when dry. Repeat if dry still sticks. No lubrication. |
Spyderman
Tinkerer
Username: Spyderman
Post Number: 6
Registered: 01-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, November 21, 2007 - 03:26 am: |
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I had similar problem and I washed the whole aperture mechanism (after removing glass) in naphta. It worked fine ever since. |
