| Author |
Message |
    
Zcream
Tinkerer
Username: Zcream
Post Number: 5
Registered: 04-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 20, 2010 - 05:57 pm: | 
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I got a beautiful 16mm movie lens - a B&H Lumax 25mm f1.9 lens. In order to clean it and relube I removed the screw helicoid WITHOUT marking the alignments.
There is one collar that attaches to the lens body, one collar to the rear C-mount and the focus ring that is on top of these 2 collars.
The rear collar has a screw that goes into a slot in the lens body collar.
However, the threads in the 2 inner collars are different, so when the align the 2 inner collars and screw into the focus ring, the lens body collar moves more than the rear collar and the screw slips out.
I will post pics soon - but I would think simple screw helicoids operate the same way.
So how do you fine folks reassemble screw helicoids ? |
Lrsnrl
Tinkerer
Username: Lrsnrl
Post Number: 2
Registered: 02-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 20, 2010 - 11:04 pm: |
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I think I know what you mean. The rear collar is
a single thread. The focus ring is multiple
thread. The multiple thread may have six starting
points. Since you didn't mark the alignments
before disassembling the lens you will have to
find the correct starting point by trial and
error. |
Zcream
Tinkerer
Username: Zcream
Post Number: 7
Registered: 04-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 23, 2010 - 02:14 am: |
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Actually the rear collar is multiple thread - but has minimal thread pitch. The threads just seem to move in the place.
I have tried everything I could imagine - 2 days. :-( |
