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Jackson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 11, 2004 - 10:58 am: | 
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I have made considerable progress since my last post regarding this camera. After purchasing a parts donor on eBay, I swapped out the entire rangefinder block and the meter assembly. In addition, repeatedly cleaning the shutter blades has freed the shutter. Unfortunately, I am left with one problem that I can't resolve.
It seems that flooding the shutter with naptha has washed away a lubricant somewhere relating to the aperture mechanism. When the aperture blades are wet, everything is fine. When they dry, the aperture ring virtually locks up. That wasn't the case when I first acquired the camera. The aperture ring was somewhat sluggish, but not stuck.
Working with the camera yesterday, I at first thought this was the result of residue remaining on the blades. Placing only a small amount of naptha on the blades is sufficient to free them. However, each time I do this, then allow the blades to dry, the problem becomes worse. Like I said, it is now at the point where the blades become really stuck when they're dry. I think what's really happening is that some of the naptha is flowing into the mechanism somewhere else, acting as a temporary lubricant.
Yesterday I removed the entire lens assembly from the parts donor and disassembled it from the rear. I was hoping to discover a simple means of access to the aperture mechanism. It seem however that this access isn't gained until nearly the last stage of disassembly. The donor is now in about a hundred pieces, and I doubt I can reassemble the lens. So, I have decided not to attempt this with the "good" unit.
Does anyone have any thoughts on this? Can the aperture mechanism be lubricated from the front after being disassembled to the point shown HERE? Has anyone else experienced these symptoms?
The aperture and light seals are the last items that need repair in this fine instrument before shooting photos. Any help with this will be appreciated! |
Winfried
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 11, 2004 - 12:26 pm: |
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First, an aperture mechanism does not need any lubricant. I think when flooding the shutter with naphta grease inside the shutter was dissolved and has reached the aperture blades/ring, and as soon it is dried it gums up the blades completely.
So now you have to CLEAN, not to lubricate the aperture blades. The aperture mechanism can be reached from the rear side of the shutter only, so you will have to separate the shutter from the body. In most cases it is held by a big retainer ring around the rear shutter collar.
Then you will have to separate the aperture mechanism from the shutter. I don't know this specific assembly but most japanese shutters follow the plot as described in the article about the Yashica Lynx5000. |
Jackson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 11, 2004 - 12:46 pm: |
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Winfried, when you say "separate the shutter from the body," are you referring to a disassembly procedure that's done after removing the entire lens plate from the body? |
Winfried
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 11, 2004 - 02:09 pm: |
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Yes, in many cases, especially when you have a powerful lens with big rear elements, you have to remove the lens plate from the body, since sometimes the rear elements cover the main retainer ring and will not pass through the film screen opening. |
Will
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, September 12, 2004 - 01:37 pm: |
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Hi Jackson,
Just recently I had the exact same problem with a Yashica Mat and Copal shutter. It took A LOT of cleaning with Ronsonol to get to work eventually (dry). I think there was some debris on the aperature pins or something. But I'm not sure as I never disassembled the aperature blades.
I also worked on another Mat before this one. It had the same problem. I flooded some graphite powder into the aperature blades and it worked very smoothly - BUT I ended up with minute "sparklers" on the elements. So I don't think this is a good solution.
Here's the link to the thread on my aperature issue.
Will
https://kyp.hauslendale.com/classics/forum/messages/2/3196.html?1094868201 |
Jackson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 14, 2004 - 08:58 am: |
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Well, you guys were right. I would have sworn it was something in the mechanism outside the blades that was freezing up.
I finally bit the bullet - the camera now looks like THIS (scary stuff for a beginner!). Last night, I cleaned the surfaces of the aperture blades repeatedly, using a Q-Tip and lens tissue, until no more yellow residue appeared on the Q-Tip. This also gave me a chance to clean the back side of the shutter blades, and I will disassemble the rear lens elements and clean any haze off the inner surfaces before reattaching the lens.
As of this morning, after drying overnight, the aperture is still free. Thanks guys! |
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