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Message |
    
Will_inoue
Tinkerer
Username: Will_inoue
Post Number: 11
Registered: 06-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 04, 2010 - 03:37 pm: | 
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Hello All,
I am working on my 50mm/f2 Summicron M and have cleaned the haze off the internal optics. But now I want to finish by re-lubricating the helical focus threads.
How is the lens focus barrel disassembled? There is a spanner nut on the back. However I found on initial attempt to remove, it won't budge. I'm just wondering if this is the way in, and if so, are they generally this tight? Is it normal thread (ccw=loosen)? Thanks in advance. |
Will_inoue
Tinkerer
Username: Will_inoue
Post Number: 12
Registered: 06-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 04, 2010 - 06:20 pm: |
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I forgot to mention this is a rigid version lens. Thanks again. |
Will_inoue
Tinkerer
Username: Will_inoue
Post Number: 13
Registered: 06-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 06, 2010 - 12:04 pm: |
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Ok I figured it out. So I will share the procedure here for anyone else who may be interested.
Remove front lens assembly (glass) by grabbing firmly and rotating CCW. Remove inner plate with serial number (press fit). Remove infinity lock with small pin face wrench. Under the infinity lock is a screw. Remove. The knurled focus scale portion of the barrel will now lift off. Rotate lens focus so brass helical and bayonet mount are approximately flush and mark both with a tiny mark on bottom of lens. This will allow you to reassemble helical properly. This is a very important step - don't forget! Remove inner lens stop with two screws. Lens will now separate by turning helical. Clean well and re-lube including brass stop. Very little grease is required. Reassemble by reverse procedure. Helical will take trial and error, but once the helical and bayonet mount are flush and your marks lines up, you know you have it. Note: there is an idler portion of the focus that requires grease also but is held together by a spanner nut from behind. This nut was very tight on my lens (wouldn't budge) and fortunatley I didn't need to re-lube this as it was still nice and smooth. I hope this helps. -Will |
Arttue
Tinkerer
Username: Arttue
Post Number: 1
Registered: 10-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 08, 2010 - 03:01 pm: |
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Thanks for the instructions!
I have 5cm Summicron rigid with focusing problem (focused to infinity, the picture is sharp at 15 feet). I think the helicals need adjusting, and therefore I have started disassembling the lense.
I tried to follow your instructions but I got stuck.
I've done the following:
- removed the lens group
- removed C shaped brass part under the lens group
- removed infinity lock, and the screw it hides
Now, the next part would be removing the knurled focus scale portion of the barrel. Did I get this right: the upper part of the lens - the one with knurls and focus distance numbers is made of two parts and the gap of these two parts runs just above the focus distance numbers?
I tried pulling the upper part from the lower part but it seems to be stuck. I also tried twisting & pulling, but that didn't help. Am I doing it wrong or should I just use more force  ? |
