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Chrisb
Tinkerer
Username: Chrisb
Post Number: 30
Registered: 01-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 27, 2013 - 05:49 pm: | 
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This lens has a sticky aperture, enough so that I'm not very optimistic that a bath will be sufficient to bring it to normal working condition. I'd like to take the aperture mechanism out of the housing, but I simply can't tell whether it's going to come out as a unit, or if the leaves and ring are just nested together.
I posted a couple pics to flickr:
http://www.flickr.com/photos/16916627@N06/8595629047/in/photostream
http://www.flickr.com/photos/16916627@N06/8596732788/in/photostream
The brass bits are the aperture unit. The outer brass ring, with the spanner holes, is held in place by 3 set screws. Loosen those set screws and it looks like it'll all come out. Whether it comes as one piece, or multiple pieces, is the question that worries me.
Thanks in advance for any help. |
Chrisb
Tinkerer
Username: Chrisb
Post Number: 31
Registered: 01-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, March 27, 2013 - 05:51 pm: |
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For some reason the link doesn't contain the entire URL. You'll need to copy and paste the entire line into your browser to get to the correct page. |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 85
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 28, 2013 - 08:32 am: |
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I have not done this job in my Rokker but in general this unit comes as a whole and it is wise not to open it further. Re asembly is too cumbersome and one blade bent? or one part missing? you will need to forget the lense. Aperture blades can be cleaned easily by flooding with iighter fluid, its damn easy job. I am sure in Rokker you can do this cleaning even without taking it out but you will need to remove both front and rear lense asemblies. The rear assembly isnt so so easy to remove and you may end up scraching a lense. If at all you need to remove rear asembly, You will need to remove the whole assembly in one piece because at leaset one inner most elment is glued in tube while other two can be easily removed. In any case if you prefer to remove the whole assembly , remember to measure the tubes distance from the mount plane because you will need to restore it to same position and also glue it in place OR you will not get infinity.
That is all for info only, I would recomend removeing the aperture aseeembly and flodding with celaning fluid and never to dismantle the assembly itself. |
Chrisb
Tinkerer
Username: Chrisb
Post Number: 32
Registered: 01-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, March 28, 2013 - 02:02 pm: |
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Purushotham,
Thanks for responding. I'm not sure I understand your answer, though. As you can see in the pics, the aperture assembly is housed in the white metal cup (aluminum, I assume), which has already been removed from the lens. What I'm trying to ascertain, is whether I can safely remove the aperture assembly from the cup without it coming apart into pieces. I have no wish to take apart the ring/blades/ring sandwich, but if the sandwich will come out of the cup without coming undone, I would much prefer that as I'm sure I would obtain a more effective cleaning. |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 86
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 29, 2013 - 01:02 am: |
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Yes the aperture assembly comes out as a unit with blades assembled in tact. Hope that clarrifies your doubt.
You can safely ignore what i said in my prev reply. That is only info which you should know abt what happenes if you chose other alternative ways. |
Chrisb
Tinkerer
Username: Chrisb
Post Number: 33
Registered: 01-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, March 29, 2013 - 11:51 am: |
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Ok, thanks for clarifying that for me. Turns out I got impatient and went ahead with putting the whole thing in a bath, and it's working very nicely now. But it's good to know that if the mechanism didn't fully clean, I'd be able to safely break it down further.
It's these little details which make this forum so valuable. |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 87
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 30, 2013 - 02:22 am: |
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I am confused a bit now? I believe when you said the 'whole thing' you meant the diapphrm assy -rite?
Well that is in order. I wodul advise to do the flooding again if it didnt fully clean. Breaking it up further isnt a good idea, bcause the chances are that u will end up damaged blades or lssing some part. More over its too cumbersome. |
Chrisb
Tinkerer
Username: Chrisb
Post Number: 36
Registered: 01-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 06, 2013 - 04:02 pm: |
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No, by "whole thing", I meant the entire 'cup' (for lack of a better word) that the diaphragm assembly and stop down linkage is mounted on/in/to. |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 90
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 07, 2013 - 08:09 am: |
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I meant that blades ettc will all be still be assemblesd and not loose. You will not need to handle blades one by one. |
