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Kkl122002
Tinkerer
Username: Kkl122002
Post Number: 26
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 18, 2007 - 07:31 am: | 
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It seems that I used too much force and stress to the Color-skopar lens when I opened it for internal cleaning. The focus screw ring is now 'sticked' there and I can not turn the focus ring again. Did anyone have this similar problem before? And is it possible to fix it? |
Shep
Tinkerer
Username: Shep
Post Number: 1
Registered: 06-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 27, 2007 - 09:25 am: |
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hey there. i've had a similar problem with a 50mm lense before.when i re-assembled it, my lense could only focus within a limited range, when i tried to focus on infinity, it would just stop.
what i found is that when i assembled it, i had not correctly aligned the threads within the barrel. for focusing there was a brass ring with 6 internal threads, which the unit containing the elements sat into. basically it was just a case of trial and error as to finding which thread was meant to go where, there were only 6 variables. hoe this has been some kind of help? |
Shep
Tinkerer
Username: Shep
Post Number: 2
Registered: 06-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 27, 2007 - 09:28 am: |
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just had an afterthought, when you put the lense back together, you didn't cross the threads of the focusing ring by any chance? like screw it in crooked? its easily done if the threads are fine. that could account for it. |
Alex
Tinkerer
Username: Alex
Post Number: 38
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, June 27, 2007 - 02:08 pm: |
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Quite often, the threads are multi-start, which means you can engage the threads in more than one position when you put the parts back together. One lens I took apart for re-greasing - it might have been a 50mm Tessar - had something like fourteen or fifteen start points. I hadn't noticed when I took it apart, and when I reassembled it, I had to try each one in turn, and it was only on the fourteenth or fifteen that I got it right. This is pretty much the same experience that Shep reports too.
I re-greased an old Russian Industar-61 lens last night, but this time I remembered to count the number of turns it took to take the mount off, and the exact orientation, so that it all went back together first time. Perhaps this is what's happened in your case. |
Kkl122002
Tinkerer
Username: Kkl122002
Post Number: 35
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 28, 2007 - 12:34 am: |
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The focus ring is in screw form. I can not find any threads in it. When I put it back, the ring could move in the first several trials. Then it was getting harder then usual and finally stuck there. |
Shep
Tinkerer
Username: Shep
Post Number: 7
Registered: 06-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 28, 2007 - 04:00 am: |
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yeah, that happened me. except then one day i tried focusing and the whole element unit just unscrewd itself and came off in my hand.quite funny when you're sitting in the pub.
what happened is that when i focused one way, it tightened the external thread but it never slackened it, so eventually it just siezed up.
is the lense stuck at a particular focus, like infinity or 45cm? |
Kkl122002
Tinkerer
Username: Kkl122002
Post Number: 38
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, June 28, 2007 - 05:26 am: |
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Yes. It stuck at ...about 8ft.
The aperture blades still function normally. |
