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Konica 200mm f3.5 - salvageable?
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PostPosted: Tue Oct 01, 2013 6:25 am    Post subject: Konica 200mm f3.5 - salvageable? Reply with quote

Got this lens from the states from evilbay in a sorry state. The seller wants me to send it back to him (he can't see anything wrong from the picture below and called it in excellent condition). However given the shipping costs, that is just throwing good money after bad.

I have all the bits and bobs for lens disassembly, except an appropriate lubricant.

The issues are; rotating the focus, causes a grinding noise. A small amount of lubricant have leaked out, and the lens assembly seems to have been extended beyond its design.

Any thoughts gents?

Image (which probably won't show because of the spam prevention - but the link is good)


PostPosted: Tue Oct 01, 2013 7:13 am    Post subject: Reply with quote

I have the same model.Obviously, the helicoid has been unscrewed and not screwed back in all the way. Should be fixable, but I don't know how to do it, sorry.


PostPosted: Tue Oct 01, 2013 12:21 pm    Post subject: Reply with quote

Could it simply be that the barrel hasnt been properly screwed back after opening the front of the lens? My Konica 135/3.2 and 3.5 both open by unscrewing the entire front section of the barrel (everything in front of the focusing collar). Unscrewing it half way would result in a lens looking pretty much as the one in your picture.

That being said, unscrewing the barrel will not affect the position of the lenses, which are screwed into another part of the lens.


PostPosted: Tue Oct 01, 2013 12:24 pm    Post subject: Re: Konica 200mm f3.5 - salvageable? Reply with quote

RnR wrote:
Got this lens from the states from evilbay in a sorry state. The seller wants me to send it back to him (he can't see anything wrong from the picture below and called it in excellent condition). However given the shipping costs, that is just throwing good money after bad.

I have all the bits and bobs for lens disassembly, except an appropriate lubricant.

The issues are; rotating the focus, causes a grinding noise. A small amount of lubricant have leaked out, and the lens assembly seems to have been extended beyond its design.

Any thoughts gents?



Tough situation. Cannot tell you what to do. Only can tell you what I would do if it were my dilemma:

Unless I had paid a fortune for the lens I would not return it (absent numbers can offer no more on this aspect).

Instead, I would try to repair the lens, even though I've not disassembled this lens prior. Following thorough cleaning, for lubricant I would use this:

Click here to see on Ebay


PostPosted: Tue Oct 01, 2013 6:44 pm    Post subject: Reply with quote

Since the above folks are commenting about the focusing helical, my first question to you is, does this lens reach infinity focus? If it does not, then it has been dismantled and the helical has not been realigned properly.

My experience with dismantling old lenses like this is often it is a trial and error process getting the focusing helical back into its correct grooves. It isn't that hard or that big of a deal. I know enough to mark a lens in an unobtrusive area to prevent this sort of thing from occurring, but often I find that the place I marked wasn't the place I should have, so it ended up being invalid, and I was stuck with reassembling using guesswork.

As far as the helical lube goes, you don't need any sort of special, exotic lube. Go down to you local auto parts store and ask for a small tub of molybdenum sulfide grease -- often called "molly-B" grease for short. It is either silver or black looking lubricant and is fairly viscous so you don't need to use much -- maybe 1/4 teaspoon or a tad more for the entire lens. If they don't have moly-b, then ask for lithium grease -- it's usually an off-white color. It will work just about as well -- it isn't quite as viscous as moly-b is, but it will work plenty fine for this application.

Wipe off all the old lubricant -- as much as you can. If you have a spray degreaser, use it to get all of it off. Then lightly coat the threads of your helical with the moly-b grease. Lay the grease down as evenly as possible. Then thread in the helical, and work it back and forth through its entire length several times to evenly spread the lubricant. Once you've done this, you're ready to reassemble the lens.


PostPosted: Tue Oct 01, 2013 9:06 pm    Post subject: Reply with quote

I have this lens and what's apparent from the photo, as skeptic says, is that the barrel is partly unscrewed. If you remove it completely (there is one grub screw that holds it which may already be loose, gone or stripped) you find the front lens assembly which can also be unscrewed in the same fashion(there's a threaded retaining ring to remove first - mine was loose enough to remove by hand). It may be that it is partially unscrewed as well which would extend it too far.


PostPosted: Wed Oct 02, 2013 8:16 am    Post subject: Reply with quote

Thanks all for the advice. I'll try to fix the lens. Lube is on its way. Work bench have been cleared. I'll keep this thread updated as I progress Very Happy


PostPosted: Sun Oct 27, 2013 3:05 am    Post subject: Reply with quote

A little update...

#1


#2


#3


From what I have read on this forum, #1 and #2 seems to show a wee bit too much of the grease? The finger wiped a small section of the edge of one of the helicoids.

I lack the right terminology for talking about this stuff. Any online reference? Or Dummies Guide to Lens Disassembly? Very Happy

In the focus ring 'helicoid' (middle in #1) the brass helicoid can rotate freely around. My gut feeling tells me that this is not right. I can see two screws separated by 90deg (#3). Should there be other screws that would keep the brass helicoid stationary to the focus ring? When I rotate the helicoid in a certain way, I hear a grinding noise. Presumably such screws would be under the focus grip material, which seems to have been repaired and may have been glued.


PostPosted: Wed Oct 30, 2013 12:44 pm    Post subject: Reply with quote

I was about to post a separate topic on something similar; re-lubing the Konica AR 135/3.2.

As you point out, the brass helical inside the focusing ring rotates freely, and that was the problem with my lens.

I disassembled my 135/3.2 and did not realize that the helical was glued inside the focusing ring (I thought it was gummed-up grease and not glue), and I removed all the glue, to get the helical completely clean. Bad mistake.


I tried gluing it back, which proved very difficult (getting the distance indications on the barrel to match up with the correct position on the helical) and also getting them lined up axially. I ended up with a paperweight...


PostPosted: Wed Oct 30, 2013 12:58 pm    Post subject: Reply with quote

sceptic wrote:
I was about to post a separate topic on something similar; re-lubing the Konica AR 135/3.2.

As you point out, the brass helical inside the focusing ring rotates freely, and that was the problem with my lens.

I disassembled my 135/3.2 and did not realize that the helical was glued inside the focusing ring (I thought it was gummed-up grease and not glue), and I removed all the glue, to get the helical completely clean. Bad mistake.


I tried gluing it back, which proved very difficult (getting the distance indications on the barrel to match up with the correct position on the helical) and also getting them lined up axially. I ended up with a paperweight...


It's wrong to hijack another poster's thread, and this thread is about the 200. So I'm gonna ask you, please, to post about your 135/3.2 experience on a new thread, or here:

http://forum.mflenses.com/hexanon-ar-135mm-f-3-2-f-3-5-disassembly-t51851.html

I've been trying for over a year to find somebody who can help me with my 135/3.2. I'm pretty desperate for help. But I'm not desperate enough to mess up the OP's thread here.


PostPosted: Wed Oct 30, 2013 11:41 pm    Post subject: Reply with quote

Its all good guardian - Konica is one big happy family Laughing

Besides I think I'm at the tail end. I found 3 small screws under the focus rubber. Once those were tightened, the focus ring helicoid no longer moved. So that seems to have been the problem. Now I just need a tip (or three Shocked) for the best way to assemble and screw together the 3 parts while aligning everything correctly... I'm sure a beer or two will help with this brain teaser Twisted Evil Very Happy


PostPosted: Thu Oct 31, 2013 8:06 am    Post subject: Reply with quote

I did not intend to "hijack" the thread; I merely thought that Konicas tele lens designs are somewhat similar and that my experience with the 135 might be applicable to the 200 as well.

Actually, Ill continue to add my experience with the helicals in the 135, as I am pretty sure the same principle applies to this lens:

First, I would screw the middle part in image #1 into the left part, making sure that the infinity mark on the barrel aligns with the vertical line on the bottom part as the helicals are screwed in as far as theyll go.

Then, I would unscrew the two parts again, and mark the point of separation on both parts (to know how to line them up for assembly).

The right part in picture #1 has two slots opposite each other. These slots fit around the two brass pins on the left part in image #1, acting as guides to keep the whole thing straight when focusing.

Getting them to line up is tricky. With my 135 (again, I believe the principle is the same here, but I may be off) I found that the right part needed to be partly screwed into the middle part before inserting them into the left part. When they all are fitted together, you can line up the slots and the pins by rotating the right and middle part, independently.

Hope that helps.


PostPosted: Thu Oct 31, 2013 11:58 am    Post subject: Reply with quote

OMG did I mess that up!!

And I never even saw it until you guys responded!! Embarassed Embarassed Embarassed

I apologize for the misunderstanding, all my fault. What I was trying to say, but did not convey at all, was that it would be wrong for ME to hijack another poster's thread!

I certainly was not accusing anyone else of doing that. But after reading the responses, and then re-reading what I wrote, I can see how you guys interpreted that like you did.

I give up. I'm never gonna get this 135/3.2 apart. I'll just go crawl back underneath my rock. Sad


PostPosted: Thu Nov 21, 2019 1:47 am    Post subject: Reply with quote

I have read all the thread and could not find how get off the frontal elements of the 57/1,4 chrome, like can do with the 135/3 2.

" open by unscrewing the entire front section of the barrel (everything in front of the focusing collar). "

I can't unscrew the barrel.

Anybody knows?