Olympus-OM
[Top] [All Lists]

Re: [OM] Oily 300/4.5. Suggestions?

Subject: Re: [OM] Oily 300/4.5. Suggestions?
From: John Hermanson <omtech1@xxxxxxxxxxx>
Date: Mon, 01 Jun 2009 08:26:26 -0400
I have privately emailed you the pdf for the 300/4.5.  Name ring often 
has 2 spanner notches in it and should just unscrew.  I think name ring 
holds front element in place. The front lens group would come out next 
and is bigger than a big coffee mug.  The diaphragm plate sits inside 
the main lens barrel and is held in by screws accessible only from the 
back, as I recall.  Whatever the method is for attaching the diaphragm 
plate to the tube, it all comes out through the front.
___________________________________
John Hermanson  |   CPS, Inc.
21 South Ln., Huntington NY 11743
631-424-2121  |  www.zuiko.com
Olympus OM Service since 1977
Gallery: www.zuiko.com/album/index.html


Chuck Norcutt wrote:
> Can the diaphragm assembly be accessed from the back alone?  I've heard 
> back from the original questioner who said he could see no evidence of 
> glue on the name ring.  However, he built a special friction tool with 
> dense foam glued to a shaped backing plate to remove the name ring. The 
> foam ripped off the backing plate when he tried to unscrew the ring.
> 
> Chuck Norcutt
> 
> John Hermanson wrote:
>> I should have added that the front group MAY unscrew without any 
>> problems.  If so, then all that remains is the disassembly of the 
>> diaphragm plate, thorough degreasing and rebuild.
>> ___________________________________
>> John Hermanson  |   CPS, Inc.
>> 21 South Ln., Huntington NY 11743
>> 631-424-2121  |  www.zuiko.com
>> Olympus OM Service since 1977
>> Gallery: www.zuiko.com/album/index.html
>>
>>
>> John Hermanson wrote:
>>> Remove front lens assembly, remove mount.  There are (I think) 4 screws 
>>> accessible from the back that hold the diaphragm assembly plate in. 
>>>  From the front, diaphragm cam, and some springs and levers may have to 
>>> come out first.  The hardest part MAY be simply unscrewing the from 
>>> group.  No set screws, just that many appear to be glued in.  Even in 
>>> the 80s, I watched Japanese techs (with 300/4.5 in a full size vice) 
>>> with giant spanners trying to unscrew the front tube.  It never budged 
>>> even after liquid wrench, alcohol, acetone, every solvent under the sun 
>>> was applied.  Spanner eventually broke.  Not really a do it at home job.
>>> ___________________________________
>>> John Hermanson  |   CPS, Inc.
>>> 21 South Ln., Huntington NY 11743
>>> 631-424-2121  |  www.zuiko.com
>>> Olympus OM Service since 1977
>>> Gallery: www.zuiko.com/album/index.html
>>>
>>>
>>> Chuck Norcutt wrote:
>>>> Anyone have suggestions for disassembly of the 300/4.5 to clean up an 
>>>> oily diaphragm?  Someone I know (not on this list) has one and asked if 
>>>> I had any tips for cleaning it.  I gave him the parts list and exploded 
>>>> assembly diagram and an old note from Clint that says the whole 
>>>> diaphragm cage is to be removed as an assembly.  But Clint's note didn't 
>>>> say anything about the best way to get in.
>>>>
>>>> Chuck Norcutt
-- 
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz