Silly lens assembly generic question: factory markings to reassemble on correct thread start?

jay moussy

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After reassembling a lens on correct thread start on frozen Isolette (and now facing the task to extract an Ektar 101mm off a bum shutter :-( ), I wonder if there were any factory markings helping with assembling lenses?
 

gone

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None that I know of Jay (been there myself on the same camera). You're stuck with trying it in different places, and using a piece of GG on the film rails to know when it's correct. It's not so bad. Put some music on that you like, sit down w/ a cup of coffee, and put it together, being sure to mark each place where it didn't work.
 
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jay moussy

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Factory workers, later repair persons must have had some system, a set of marks?

@momus , my crude markings on the Isolette worked, but I cheated, left the focus ring on!
Now, I need to take apart an Ektar 101mm off a bum shutter, so I was hoping there would be a set of markings.
 

John Koehrer

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Magic marker/sharpie/scribe mark before you take the thing apart
Front group focus are usually continuous thread so no problem. interrupted
threads................Mark or scribe.

Wonder how the did it in factories too.
 

albada

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AgX said:
They just used arbitrally any of the starts and then focused and set the distance scale and arrest to fit.
Click to expand...

I carefully unscrew the helicoid, and I scratch marks on both pieces of at the point where they separate. Also, I count turns, so that I can get it back close to infinity. When it's back together and close to infinity, I locate the dents left in the helicoid from the set screws (grub screws) for the focus ring, letting me restore the exact adjustment when it left the factory.
 

AgX

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But in the case it got disassembled before doing a marking, momus gave the good avise then to (temporarily) mark the start positions (or rather the get-loose positions) that did not work, until you find the right one.
 
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