Re:Nikon 55mm F3.5 Micro and 55mm F2.8 Micro repair

Search the archives for the 55mm 2.8 - there was someone else with the
same lens and issue. Cleaning the blades can be easy or not, depends
how far you want to disassemble.
I conclude from repeat issues that many of the early AF Nikkors have
this problem, as well as a smaller number of earlier lenses.

I have a 35mm f2 that had bad leaking onto the blades (among others),
but I didn't want to risk total disassembly, so..

Removing the rear element is pretty simple, unscrew the back plate,
lift all bits out that are loose and note where they go.
The back elements of the lens will simply unscrew like taking the lid
off a bottle - be careful - the back element and the next couple of
elements will spill out as soon as you turn the lens over - so have a
static and dust free cloth to tumble them onto.
Depending on the size of the metal ring around the rear element you may
or may not be able help them onto the cloth with your fingers. On the
35mm f2 I can grab the ring and turn the lens over, catching the next
elements in the ring as well, then place them on the cloth - but not
all lenses allow this, you may have to spill them.

Look into the back of the lens where there is now an opening straight
to the back surfaces of the aperture blades - clean these GENTLY with a
q-tip and do not rub against the direction of the blade overlap - ie
wipe "down the steps"; so to speak.
With a paperclip or tool move the coupling mechanism in the coupling
hole to open the blades to various apertures - clean at a variety of
openings because the blades overlap and all the gunk will not be
exposed for cleaning unless you do this.

Once the blades are "snappy" again, operate the aperture mechanism 30
or 40 times - this will migrate gunk from the front of the blades to
the back, and clean again. Then operate the blades again, and clean
again. Do this until no black or gunk appears on the q-tips.
Reassemble - once you have the aperture ring on, move the coupling
lever a couple of times to make sure it engages properly - if you
don't, and screw the back plate on, the aperture won't move or will
only move a bit.

I use about 24 q-tips on the first cleaning.

Because this will not completely clean the front of the blades or
peripheral mechanism, you will find that after 10 to 14 days the blades
will stick again, and you will have to clean again.
After the second cleaning the interval will be longer, and you will
need to repeat cleaning several times but over 10 cleanings the lens
will come clean.

Th advantage of this method is you don't need to disassemble the front
of the lens. It sounds like a lot of work, but removing the rear
elements is actually quite simple and quick. I have gotten in the habit
of giving the blades a clean before needing to shoot anything, which I
did two days ago, but I can't recall the last time before that.

Good luck - Will

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.

I used the same technique for my 28mm 2.8 AIS. Removed the ring at the
back, then the three elements in the back fell out and I had access to
the aperture blades. I used the q-tip, but dipped it in isopropyl
alcohol. Had to clean the blades only once and it's working fine now.

But, I don't think the 55mm micros are that easy. I've 55mm 3.5 and
2.8. The 3.5 has smooth focus, but the 2.8 has very very stiff focus.
Never had oil problems on these.

On 10/10/07, will < willr%40chebucto.ns.ca">willrchebucto.ns.ca> wrote:

> Removing the rear element is pretty simple, unscrew the back plate,
&gt; lift all bits out that are loose and note where they go.
> The back elements of the lens will simply unscrew like taking the lid
> off a bottle - be careful - the back element and the next couple of
> elements will spill out as soon as you turn the lens over - so have a
> static and dust free cloth to tumble them onto.
&gt; Depending on the size of the metal ring around the rear element you may
> or may not be able help them onto the cloth with your fingers. On the
> 35mm f2 I can grab the ring and turn the lens over, catching the next
>; elements in the ring as well, then place them on the cloth - but not
> all lenses allow this, you may have to spill them.
&gt;
> Look into the back of the lens where there is now an opening straight
> to the back surfaces of the aperture blades - clean these GENTLY with a
> q-tip and do not rub against the direction of the blade overlap - ie
> wipe "down the steps"; so to speak.
&gt; With a paperclip or tool move the coupling mechanism in the coupling
> hole to open the blades to various apertures - clean at a variety of
> openings because the blades overlap and all the gunk will not be
> exposed for cleaning unless you do this.
&gt;
> Once the blades are "snappy" again, operate the aperture mechanism 30
> or 40 times - this will migrate gunk from the front of the blades to
> the back, and clean again. Then operate the blades again, and clean
&gt; again. Do this until no black or gunk appears on the q-tips.
> Reassemble - once you have the aperture ring on, move the coupling
> lever a couple of times to make sure it engages properly - if you
> don't, and screw the back plate on, the aperture won't move or will
>; only move a bit.
>;
> I use about 24 q-tips on the first cleaning.
>
&gt; Because this will not completely clean the front of the blades or
> peripheral mechanism, you will find that after 10 to 14 days the blades
&gt; will stick again, and you will have to clean again.
&gt; After the second cleaning the interval will be longer, and you will
>; need to repeat cleaning several times but over 10 cleanings the lens
>; will come clean.
&gt;
> Th advantage of this method is you don't need to disassemble the front
&gt; of the lens. It sounds like a lot of work, but removing the rear
>; elements is actually quite simple and quick. I have gotten in the habit
&gt; of giving the blades a clean before needing to shoot anything, which I
> did two days ago, but I can't recall the last time before that.
&gt;
> Good luck - Will
>;
>
>
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