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85mm lens teardown

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Hans Giersberg said:
Neat. Is that rust in the last shot (the pins on which the aperture blades pivot)?

--
I Reject Your Reality And Substitute My Own

Web Site - http://www.visual-journeys.com/
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Yes. It's not eating into the actual metal though - it literally wipes right off.

I got a little further than the last pictures - I actually got the whole front element apart. The casing screws together tightly, and it has two notches on the front of the element designed for a special lens spanner tool to grip and twist it apart. I fashioned my own out of a metal phone wallplate that I modified to clear the front glass element and still grip the notches - a little bit of force and it came right apart.

That's where most of the water was stuck - there was literally a pool of water inside that casing, and a WHOLE lot of "crumbs" - minerals, dirt, sand, etc. If I can get it all cleaned up and back together, it just might work okay again :)

--
Jesse

http://www.flickr.com/photos/sprocket87
 
From my practice in disassembling lenses - I'm affraid You've went too far. But if You have some luck - You still have chances to put everything into one working thing. Pay attention - the focusing thread may have several "beginnings" and You have to find the right one.

--



http://www.sviesorastis.lt
 
How easy is it to get the the aperture blades without total dissasembly? - is that possible?

--
Please ignore the Typos, I'm the world's worst Typist

 
Leo "Zoom" said:
From my practice in disassembling lenses - I'm affraid You've went too far. But if You have some luck - You still have chances to put everything into one working thing. Pay attention - the focusing thread may have several "beginnings" and You have to find the right one.
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Acknowledged. You may be right, but I had to go this far to let the moisture out and. It was sealed in the front element (literal pools of water) and wasn't going to come out on its own. If it doesn't work again, I'm no worse off than I was previously (a repair/cleaning bill would cost more than the value of the lens itself). Worst case, the lens is just as unusable as before. Best case, I can get it working satisfactorily again. Might as well try :)

Thanks for the tips. Re-assembly will certainly be tougher than teardown. I won't even attempt that until next week.
--
Jesse

http://www.flickr.com/photos/sprocket87
 
AdamT said:
How easy is it to get the the aperture blades without total dissasembly? - is that possible?
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You have to tear into it pretty far, at least if you're coming from the rear-element down. The aperture blades are immediately behind the 2 front element lenses, secured by a thin metal plate with guides that cause the blades to open/closes as it rotates. That plate is secured by a circlip (I didn't have the special pliers to remove it so I used two thumbtacks :D)

But to even get there you have to remove about 60% of the lens. The pics aren't quite posted in chronological order, but you can see from the last two pics everything that had to come out before the aperture blades are accessible.

Now, in retrospect it might be possible to come in the other way - via the front element - and get there in just a couple steps. As I described above, you need to unscrew the front element using a spanner tool (or makeshift tool) that sits in the two notches on either side of the rubberish front element seal. Once you unscrew that element it may simply pull out with the aperture housing in tact. But I can't guarantee that, since I came in from the rear element and it's possible that another retaining mechanism was removed in the process.

--
Jesse

http://www.flickr.com/photos/sprocket87
 
OR... you could have sent it in to Nikon and have them take a look at it! I am sure what ever warranty might have been on that lens is now void. If there was no warranty, then the cost for Nikon to salvage the lens comparative to the value of the lens would have been the key question.

If the cheaper option was doing it yourself, then I think it was more necessity than bravery. In any account, I hope this works out for you and that your 85 f/1.8 lives to shoot another photo (well I guess its technically the camera that shoots- but you know what I mean).

If the lens works again, it will also be interesting to see if the lens is as sharp and accurate at varying aperture settings? Perhaps pulling it apart is easier than putting it back together, and in doing so, specific alignment and configuration is needed.

Time will tell, but please post your results.

Good Luck!
 
I would'nt attempt a complete dissasembly whithout knowing the exact procedure, but the bill from Nikon would maybe be prohibitive (or sent back with a "beyond repair" note), so what can you lose?

I once reassembled a simple extension tube that dissassembled by itself in the camera bag...took me as much as an hour to put back together the d&%n thing, due to minuscule ball bearings that had to be fished out of the bag's creases, and would'nt get on track later on...it's really a specialist's job...

Hope you took good note of every step so you can do the play by play in reverse order...

I would be especially careful with the ribbon that connects the lens electronics with the lens mount. It can be broken very easily. Don't know what will happen to the lubricants. Will there be mineral deposits under the ribbon's pressure contacts? You'll have to adjust the maximum aperture among other things. It can be done at least partly on a fully assembled lens btw, on this particuliar lens (a small external adjustable stopper).
good luck and post the results.
--
Jean Bernier

All photographs are only more or less credible illusions
 
Sprocket87,

I'm sorry this happened to you, but do appreciate you sharing this part of the process.

I'm not sure what this says about me, but I like looking at the photos, and wish they were even clearer. I don't use that particular lens, but there's something compelling and useful about seeing the inner intricacies. Helps me appreciate how complex these lenses are, but there's more to their appeal than just that.

Reminds me of my kids taking apart radios and clocks. They still love looking at the photo of their last clock project. I posted one below.

I'll bet against the chances of getting your lens to function again, but I'd love to be proved wrong. Before you try I encourage you to make more images, maybe with a tripod or bounce flash. Please keep us posted on how it turns out. -C.

 
sprocket87 said:
But to even get there you have to remove about 60% of the lens. The pics aren't quite posted in chronological order, but you can see from the last two pics everything that had to come out before the aperture blades are accessible.
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Damn - All well .. a collegue has one where the blades are jamming for some reason (not oil) and was goig to attempt it as I'm pretty handy at fixing lenses - over the years I've rescued a bunch of 70-210s which have a tendency to fall apart internally due to screws coming loose and kept my press-thrashed 20-35 F2.8D going until the cams and helicoid wore out..
sprocket87 said:
Now, in retrospect it might be possible to come in the other way - via the front element - and get there in just a couple steps. As I described above, you need to unscrew the front element using a spanner tool
Click to expand...
I've got one - very handy for the 70-210 repairs mentioned above - I hate messing with the reat end of Nikon lenses anyway with the fragile electrical connectors & ribbons and shims falling about all over the place

--
Please ignore the Typos, I'm the world's worst Typist

 
That's a great picture... :-) I'm sure the kids would hang a poster of it !
--
“There is nothing in a caterpillar that tells you it's going to be a butterfly.”
Buckminster Fuller
http://www.flickr.com/photos/archivue/
 
Jeez, sprocket87, you should have posted a "warning: graphic images" label in your title. I think I'm going to have nightmares about my beloved 85 1.8 in bits and pieces. Gotta go now, my poor lenses are huddling in the corner, and I need to tell them its going to be alright.

:)

Good luck with the surgery. Hope she'll see again soon.

wigs
 
sprocket87,

Thanks. This is extremely interesting and useful.

A quick question for you (or anyone else). How do you deal with frozen screws? I have taken apart an old teleconverter and am now taking apart a Nikon film body. I have encountered screws that will not come out. I have stripped screwdrivers and the screws. I have tried Liquid Wrench, but not much luck. Also tried to remove any paint or glue, but only partially successful. I now drill out the frozen screws.

Any suggestions would be most welcomed.

--
http://www.flickr.com/photos/9476880@N02/
 
They use some sort of locktite on certain screws to keep them secure. Some are extremely hard to get out, and you must be very cautious because if you strip a screw head you are done - no way to get past it after that.

My technique has yet to fail though: I take jeweler's screwdrivers (the small metal ones with rotating endpieces), and put down as much pressure as I can on the back of the screwdriver, pushing down on the screw. Then I take a big pair of pliers (with textured teeth to grip the shaft of the screwdriver) and slowly rotate it to get the screw started. It basically acts as a lever and amplifies your rotational force, and makes it easier to supply a lot of downward force to keep the screwdriver head from slipping/stripping out the screw.

Also make sure you're using the best-fitting screwdriver possible to minimize risk of stripping.
pmong said:
sprocket87,

Thanks. This is extremely interesting and useful.

A quick question for you (or anyone else). How do you deal with frozen screws? I have taken apart an old teleconverter and am now taking apart a Nikon film body. I have encountered screws that will not come out. I have stripped screwdrivers and the screws. I have tried Liquid Wrench, but not much luck. Also tried to remove any paint or glue, but only partially successful. I now drill out the frozen screws.

Any suggestions would be most welcomed.

--
http://www.flickr.com/photos/9476880@N02/
Click to expand...
--
Jesse

http://www.flickr.com/photos/sprocket87
 
Clark Thomas said:
I'll bet against the chances of getting your lens to function again, but I'd love to be proved wrong. Before you try I encourage you to make more images, maybe with a tripod or bounce flash. Please keep us posted on how it turns out. -C.
Click to expand...
Thanks for the words of encouragement Clark! I doubt it will function properly again as well, but I had to try :)

And I will definitely get some better quality pictures before I piece it back together. I've got my D700 on order and it should be here early next week. I'll put my 60mm micro Nikkor to use for ya ;)

--
Jesse

http://www.flickr.com/photos/sprocket87
 
I would guess that they'd use blue loctite since most of the other stuff takes a torch to break free and with such small screws, they'd have to use that. I am guessing here, but my auto-mechanic skills lead me to believe that.

Nice tear down of a lens even if you did go to far. I hop you can get it back together, but if not, it was fun to watch!
sprocket87 said:
They use some sort of locktite on certain screws to keep them secure. Some are extremely hard to get out, and you must be very cautious because if you strip a screw head you are done - no way to get past it after that.

My technique has yet to fail though: I take jeweler's screwdrivers (the small metal ones with rotating endpieces), and put down as much pressure as I can on the back of the screwdriver, pushing down on the screw. Then I take a big pair of pliers (with textured teeth to grip the shaft of the screwdriver) and slowly rotate it to get the screw started. It basically acts as a lever and amplifies your rotational force, and makes it easier to supply a lot of downward force to keep the screwdriver head from slipping/stripping out the screw.

Also make sure you're using the best-fitting screwdriver possible to minimize risk of stripping.
pmong said:
sprocket87,

Thanks. This is extremely interesting and useful.

A quick question for you (or anyone else). How do you deal with frozen screws? I have taken apart an old teleconverter and am now taking apart a Nikon film body. I have encountered screws that will not come out. I have stripped screwdrivers and the screws. I have tried Liquid Wrench, but not much luck. Also tried to remove any paint or glue, but only partially successful. I now drill out the frozen screws.

Any suggestions would be most welcomed.

--
http://www.flickr.com/photos/9476880@N02/
Click to expand...
--
Jesse

http://www.flickr.com/photos/sprocket87
Click to expand...
--
http://www.flickr.com/photos/thewenzels/
 
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