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chris burck
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, March 27, 2005 - 04:49 pm: |
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greetings to all. i acquired one of these lenses and wanted to do an internal cleaning and relube the helicoid. things got off to a nice start using rick oleson's diagram (http://rick_oleson.tripod.com/index-81.html) as a guide. some minor fungus and haze in the front elements cleaned up real nice. but then i got stumped. i just can't seem to take the disassembly any further, either by continuing from the front or approaching from the rear. there are three concentric retaining rings in the rear, the outermost of which i believe may serve merely to lock the other two in place. it came out. the other two turn but don't seem to be moving either forwards or backwards. can anybody help? |
chris burck
Rating: N/A Votes: 0 (Vote!) | Posted on Sunday, March 27, 2005 - 04:55 pm: |
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i should point out that i *could* proceed with the disassembly from the front, at least as far as removing the (diaphragm) blade nest, though i haven't yet tried that. my preference would be to separate the diaphragm assembly as a unit, which i should be able to do unless i am incorrectly reading the sketch (http://rick_oleson.tripod.com/index-81.html). anyway, i'd really appreciate any help. -chris |
rick oleson
Rating: N/A Votes: 0 (Vote!) | Posted on Monday, March 28, 2005 - 08:15 am: |
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The innermost of the 3 rings in the rear is a retaining ring for the rear elements; after removing this ring, the glass must be pushed out from the front to remove it. I believe it's the next ring out that you remove to separate the inner lens barrel from the focusing mount - this ring (in my lens) has 4 notches rather than the usual 2. then, to unscrew the aperture ring off of the barrel, you have to remove another retaining ring at the rear (this one is about 44mm in diameter) and pull off the preset ring, and then remove both the dipahragm stop pin and the diaphragm coupling pin to allow the ring to unscrew. at this point you will have just the barrel with the diaphragm still in it. any disassembly beyond this point will leave you with loose diaphragm blades. = |
chris burck
Rating: N/A Votes: 0 (Vote!) | Posted on Tuesday, March 29, 2005 - 09:32 pm: |
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rick, thanks for the input. just one other thing. are they right-hand threaded, or left-, or some combination, on your lens? thanks again, -chris |
chris burck
Rating: N/A Votes: 0 (Vote!) | Posted on Wednesday, May 11, 2005 - 05:55 pm: |
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just an update for anyone interested. still no success! as yet unable to get any movement from the two inner rings. they turn, but no visible inward or outward movement, nor discernable movement in relation to one another. and the third, outermost rng which i had removed did not allow me to separate any part of the lens assembly. i thought perhaps something else (whatever they attach to?) was moving with them, and it might help to reinstall the outer ring so as to 'anchor things'. but now i can't get that ring back in! it's as though it's just ever so slightly oversized, and doesn't want to reseat so i can screw it back in. >groan< matters aren't helped by the fact that the rear element is so far in from the end of the lens barrel. . . . this one's going to have to go on the back burner for a while. cheerio, -chris |
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