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on Mar 22, 2017 0:41:10 GMT
Posted: Mar 22, 2017 0:41:10 GMT
I unscrewed the three screws by the aperture ring to see if I can take it apart to clean it.. And the aperture ring is now stuck. I had it at F1.7 when I unscrewed the screws; and now it's stuck; won't turn at all. So I was thinking of taking the lens apart from the front as there are no screws in the back like the Nikkor lenses. I unscrewed the front piece, then there was a piece that required a spanner, I took that off, and now I'm stuck.. I don't know how to get past this point. I do see what looks like a spring pin on the inner circle, I'm not sure if I'm suppose to depress it or pull it or leave it alone. I've taken a pic of it; showing at 6 o'clock. The second (silver) part slightly outer ring, has some flat holes on the side, difficult to spanner, so I don't know. Looking into the barrel, I see some screws that are holding a brass thin film, tight fit, I'm scared if I unscrew the screws, I won't ever be able to get them back in.. Any help appreciated!
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on Mar 22, 2017 1:31:08 GMT
Posted: Mar 22, 2017 1:31:08 GMT
It would be good to have photos of what you already did to the lens so one could make an informed suggestion as to what step to take next. Going in from the front is not helpful in your situation. I don't have a 1.7 to go by, but my 1.9 has three set screws around the periphery of the lens that should release the mounting plate, which will expose the mechanics for the aperture selection. I think. I've never had reason to take this lens apart.
PF
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on Mar 22, 2017 1:48:41 GMT
Posted: Mar 22, 2017 1:48:41 GMT
The forum only let me attach 3 pics.. I took the 3 periphery screws off; you think I should be able to "twist" the back of the lens off?? There are no screws whatever on the back side. (Frustrating!!) The picture is all I have done to it..
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on Mar 23, 2017 1:14:00 GMT
Posted: Mar 23, 2017 1:14:00 GMT
It would look to be something you just pull off, but then Yashica was known to use glues in certain places. Maybe a slight tap would loosen it. I could try mine to see how it is removed, then report back.
PF
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on Mar 23, 2017 17:05:32 GMT
Posted: Mar 23, 2017 17:05:32 GMT
Thank you! Any help appreciated
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on Mar 25, 2017 2:33:09 GMT
Last Edit: Mar 25, 2017 2:37:02 GMT by ridgeblue99
Okay, since you have the three set screws out, starting with the lens facing down, and the aperture automatic actuating pin at top dead center (this also puts the center point indicator on the lens at bottom dead center as it faces you), and the aperture selector ring set at minimum, you slowly pull up on the aperture selector ring towards the rear of the lens, with a rocking motion to help get things moving. This will work free the ring that held the three set screws. Be very careful at this point, because the ring holds the detent for the f stops. Once it starts to come loose, make sure you don't pull it off in a quick, jerking motion. The steel detent ball might stick to the selector ring because of the lubricant, then again it might not. Do this over something that will catch the ball in case it falls out, like a shallow pan.
After you have the set screw ring off, you'll see the detent points on the aperture selector ring, and about 95 degrees up to the right of the last point (minimum aperture) is a slot in the ring, which is supposed to connect with the aperture actuating arm, just in case you don't see something kind of copper colored in the slot.
If you now take the aperture selector ring off, you can see the aperture actuating arm about 85 degrees to the right of the aperture automatic actuating pin if it is at minimum aperture. Moving the actuating arm towards the pin will give you larger apertures until you reach maximum. You can hold the automatic pin down to see if the aperture actually follows the setting of the actuating arm. if it does, then the aperture is not jammed. Put the aperture selector ring back on, making sure the aperture actuating arm is in the slot, then operate the aperture again while holding down the automatic pin to make sure it is operating freely. Set the aperture to minimum for the final step.
For the last step, put the set screw ring back on, making sure the detent ball is at the point of minimum aperture, as set in the previous step. Then carefully put the set screws back in, and tighten them.
If none of this gets the aperture to perform correctly, and it is truly jammed, then you will have to continue going in through the front. Hopefully the aperture actuating arm is not damaged, which would be the most likely source of a jam. The other source would be an aperture blade that has worn out its mount, or been knocked loose somehow.
PF
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on Mar 25, 2017 3:41:59 GMT
Posted: Mar 25, 2017 3:41:59 GMT
Ok. At least you are saying the aperture ring is removable with the three screws out.. I'll try it tomorrow morning.
The appetite tying it's jammed though, let me see if I can't coax it off.
A few pictures, I saw spanner pin holes in the back of the m42 mount thread part, but mine don't have these.
I'll update when I try. Thank you for the help!
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on Mar 25, 2017 3:53:56 GMT
Last Edit: Mar 25, 2017 3:55:01 GMT by twoblink
Oops i.e. Posted twice.
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on Mar 26, 2017 5:30:06 GMT
Last Edit: Mar 26, 2017 5:30:57 GMT by twoblink
So i put the lens back together and the aperture control seems disconnected.. So I took the entire lens apart but I still can't get aperture blades to appear when I actuate the aperture... Moving the f-stop tab directly on the inner group didn't yield aperture blades either.. The entire lens is taken apart except for lens group... Hope I can put it back together. I'll make a video tomorrow to store where I'm stuck, hopefully someone can help me!
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on Mar 26, 2017 20:53:49 GMT
Posted: Mar 26, 2017 20:53:49 GMT
I'm now fairly confident that I can put the entire lens back together!
The rubber grip has come loose, recommendations what kind of glue for rubber to aluminum? I'm thinning rubber cement.
I'm also waiting for my Nikon f-mount adapter to arrive in the mail.. Read online that since you lose infinity zero anyways, after I put it on the adapter, I should be able to back set the lens group so infinity happens on the Nikon bodies...
If I'm successful at restoring the lens, I'll make a video..
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on Mar 27, 2017 2:42:46 GMT
Posted: Mar 27, 2017 2:42:46 GMT
Rubber cement will be fine. Another possibility is the automatic aperture actuating pin is no longer engaged, so you would definitely need to remove the element groups to fix that.
PF
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on Mar 28, 2017 3:08:06 GMT
Posted: Mar 28, 2017 3:08:06 GMT
And.. I might have spoken too quickly.. there are two gutters on the inside and two brass tabs that fit into it.. but when they fit into it; the lens will not rotate.. so I have NO CLUE how it exists and still allows the lens to rotate.. got home too late today to film it; and am on a business trip for the week; shall be continued.. I'm looking over videos of Zeiss Planars and Pentax lenses and whatever other lenses I can find that is m42 mount to see if I can see similar construction...
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on Apr 3, 2017 3:49:35 GMT
Posted: Apr 3, 2017 3:49:35 GMT
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on Apr 4, 2017 2:11:00 GMT
Posted: Apr 4, 2017 2:11:00 GMT
First thing I do when starting repairs on a camera or lens is to make sure the battery is fully charged on my P7700 so I can make a visual document about the process for later reference. I also keep a pad of note paper handy for other info not so visual. Haven't taken one of these apart before, but here is the album of a DSB 50/1.9 I started on, and got halfway through before it got set to the side. flic.kr/s/aHsjDyepjEPF
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on Apr 4, 2017 14:18:06 GMT
Posted: Apr 4, 2017 14:18:06 GMT
I have taken quite a few Nikkor lenses apart; so in my zeal; I didn't document it.. Someone on the discussion suggested MikeNo on youtube; I have taken a look at his Minolta ones; and they are pretty close. sigh... My wife is yelling at me because I have the lens apart on the table...
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