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Message |
    
Warpedwoof
Tinkerer
Username: Warpedwoof
Post Number: 1
Registered: 05-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 06, 2009 - 12:01 pm: | 
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Hi folks. I'm new to the forum, so a hello to all.
I'm reassembling the above lens after removing water stains on the elements, and I'm having difficulty getting the focusing helicoil threads to engage with the body threads. I've thoroughly checked the threads for imperfections, I've checked the roundness of the coils, I've even carefully tried warming the front housing and cooling the body to loosen the fit a fraction, but I can't get the threads to merge. At best they seem to jam no matter how one is rotated against the other and how square I try to keep them. They originally came apart without any difficulty. And there is nothing in the reassembly that would interfere with their merging. Would I be missing something here? Any perspective on this would be heartily appreciated. cheers.......Paul |
Glenn
Tinkerer
Username: Glenn
Post Number: 573
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 06, 2009 - 05:03 pm: |
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Presuming that you are aligning the parts at the original starting point, you should carefully examine the actual ends of the threads. Wear can produce very thin 'chisel' shaped starts, and these can very easily get deformed during the stripping and subsequent cleaning procedure. I use a diamond hone on the outer edge of both parts, to give a small chamfer.
I have also found that on large diameter helicals, pushing the parts together whilst rotating will cause a jam. Pulling the parts 'apart' during rotation will allow the parts to be screwed together quite freely. Obviously one does not actually pull the parts apart, but once the threads engage just try and stop the leading edges of the threads rubbing together. The action is actually easier to do than explain, but once you experience success the action becomes automatic. |
Kiron_kid
Tinkerer
Username: Kiron_kid
Post Number: 4
Registered: 12-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, June 28, 2009 - 09:01 am: |
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We may have the repair manual for that lens in the Kiron Klub.
Kiron Kid |
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