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Re: [OM] 20mm f/3.5 Zuiko Macro with stuck diaphragm

Subject: Re: [OM] 20mm f/3.5 Zuiko Macro with stuck diaphragm
From: Fernando Gonzalez Gentile <fgnzalez@xxxxxxxxxxxxx>
Date: Tue, 25 Nov 2008 11:50:58 -0300
horrid English grammar on second lecture -  excuse me , list.

Fernando

Fernando Gonzalez Gentile wrote:
> Same warning.
>
> The most reputed repairman in Montevideo, told me more than once that is 
> not a common grease.
> My 21/3,5 suffers from the opposite illness, fortunately not in the 
> aperture ring but in the focusing ring: it is rather loose, 'though I 
> can perfectly use the Zuiko. Asked more than once if he could fix this 
> almost non-issue, but he refused; alleging that kind of lubricant was 
> very difficult to find here in town. I suppose both the aperture ring 
> and focusing ring use the same type of lubricant.
>
> FWIW
>
> Fernando.
>
> Chuck Norcutt wrote:
>   
>> A warning that I'm overstepping my bounds here but, from looking at the 
>> parts diagram, I would agree that it looks as though the aperture ring 
>> should simply slide off.  If the grease has solidified to the point of 
>> preventing the ring from turning (as Mark's note hypothesized) then I 
>> would not be at all surprised that it's that same solidified grease 
>> that's acting as a glue between the two parts and also preventing you 
>> from sliding it off as well as turning it.
>>
>> If it were me I would very gradually feed some drops of a solvent such 
>> as Ronsonol lighter fluid around the inner diameter of the aperture ring 
>> and perhaps on its back face.  Also maybe a drop or two in the groove 
>> that appears to slide over the actuating pin Mark mentions.  Just don't 
>> use so much that it ends up dripping and running inside the lens.
>>
>> If the grease is totally dried out and has evaporated off all of its 
>> volatile components I'm not sure warming can help much.  It probably 
>> does need a solvent to loosen it up.
>>
>> On the other hand I think this is a very expensive piece of glass... so 
>> ignore what I just said.  :-)
>>
>> Chuck Norcutt
>>
>> Alan Wood wrote:
>>   
>>     
>>> In 2001, Mark Dapoz kindly provided some advice:
>>>
>>> Chances are that the grease around the aperture ring has solidified
>>> and is preventing it from turning.  Use a rubber stopper to twist the
>>> front part of the lens off, it's just a big retaining ring.  The
>>> aperture ring should then easily come off.  You will then see a
>>> little pin sticking out from the barrel.  Try moving that pin, it
>>> should move freely and close the aperture.  If it doesn't then you
>>> have other problems and it's best to get the lens CLA'd.  If it does
>>> move freely, just clean up the grease on the aperture ring and
>>> re-lube it using an appropriate grease.
>>>
>>> ----------
>>>
>>> It has taken me 7 years, but I have finally managed to unscrew the
>>> front ring (the one that says ZUIKO MACRO etc.).  Now I cannot get
>>> any further.  The aperture ring (the first knurled ring) will not
>>> come off.  I have tried gently warming it.
>>>
>>> Please does anyone have any suggestions for loosening it?  Maybe a
>>> solvent?
>>>
>>> Thank you
>>>
>>> Alan Wood http://www.alanwood.net (Unicode, special characters,
>>> pesticide names)
>>>
>>>
>>> ------------------------------------------------------------------------
>>>       


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