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Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 50
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, December 12, 2009 - 07:42 pm: | 
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I just received a Yashica Mat 124 that I bought off feeBay, and it is in really nice shape except for a bit of fungus in the taking lens. The fungus is actually entirely resident within the group(s) behind the shutter.
I have a lens spanner, but because the rear element is recessed so deeply into the front of the camera (looking at it from the back), my spanner's shanks aren't long enough to reach it.
So. I can look for a special spanner with very long shanks, or I can make one on my lathe and mill, or I'm hoping I can just remove the entire assembly from the front of the camera that contains both lenses and everything else associated with them.
I d/l'd the Yashica D repair "manual" that's in the "Repair Manuals" section, which is really just a series of exploded diagrams, but if I can assume that the dismantling procedure is the same or similar with the 124, it appears that removal of the entire lens assembly is possible.
Going by the Yashica D diagram, it looks like I should probably start by peeling back the leatherette on the front standard. What I'm not clear on is what to do next. The diagram seems to suggest that I can remove the entire standard at this point -- which is what I want to do.
So, if you've had to do this before, I'd appreciate your feedback. I really don't like tearing into a camera blind (which I've done many times), only to find there was a far easier way to do what I wanted to do. Just trying to save time and keep the aggravation factor down to a minimum. |
Finnegan
Tinkerer
Username: Finnegan
Post Number: 15
Registered: 09-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 13, 2009 - 04:53 am: |
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I have had to reassemble a D before but really the lens units (front half and back half) simply unscrew and come out without disassembly. Use a rubber thingy to apply pressure and remove the front or rear lens half (rear better). You can always leave the shutter open on B to reach in and clean the other half of the lens if need be. The D is a three element lens and the Mat is a four element lens.
Tell me how it goes because I have to do mine also except mine has what looks like grease in there. |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 1022
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 13, 2009 - 01:27 pm: |
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If you remove the front leatherette (which will probably come of in tiny little pieces), the next step is to remove the front fascia cover, which is in 2 pieces - the outer rectangular part and the inner part with the shutter and aperture dials and the lens bayonets on it. This is a matter of pulling out a few screws under the leatherette. From here you can remove the whole front standard, shutter, viewing lens and all. I have some rough sketches here (scroll down a little): http://rick_oleson.tripod.com/index-158.html |
Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 51
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 13, 2009 - 10:29 pm: |
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Thanks for the feedback guys. Rick, I printed out your notes. They don't differ substantially from the drawing for the D.
I was doing a good job removing the leatherette until I got to the right side, and then it got recalcitrant. Ended up coming away in several pieces.
All I had to do to remove the front standard was undo four brass slotted screws and it came off. Had to grind down the appropriate-sized screwdriver to get it to fit the slots. The rear element of the taking lens came off easily enough using my lens spanner. As for the fungus, I was able to remove all of it on the interior and exterior of the element, but the interior fungus left some tracks in the coating. Nothing very noticeable, so I don't really think it will have much effect on image quality.
Assembly has been a bit tricky. A few comments:
There are small brass horseshoe-shaped shims on the mounting flanges or whatever you want to call them (where the four brass screws thread into) that seem to matter. A couple fell off and I didn't notice until I had reassembled the camera. I noticed then that the shutter button was not coming out all the way and the Lock wasn't working. So be sure to keep track of these. I'm not sure they were the problem, but they might have been. They were secured with what looks like shellac and can become detached easily. I used shellac to re-secure them.
There are two posts extending from the back of the standard that engage a couple of levers used for the meter. They are part of the mechanisms associated with the aperture and shutter speed dials. The dials should be rotated such that each post is moved as far toward the center of the standard as possible (f/3.5 and B respectively). The standard assembly must be inserted to position the aperture post inward of the left-side lever, which permits the shutter speed post to be positioned so that it will engage the right side lever correctly.
I've been having trouble getting things to fit back together right, though. The camera body has a lever that cocks the shutter and another one that the cranking/cocking operation resets. This second one allows the crank to wind again once its been depressed. I'm running into a problem where I can't get the crank to wind -- it's binding on something somehow. Haven't quite figured out yet what the little secret is. I'll let you know once I've figured it out.
Michael |
Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 52
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, December 14, 2009 - 03:46 pm: |
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Okay, I got the camera back together today and everything is working normally.
The trick to getting it back together so that everything is working properly is to remove the front bezel or whatever it's called -- the piece that holds the lenses' bayonet mounts. It's held to the standard by five small cross-head screws. I hadn't done this, although Rick shows it being removed in his notes. With this off, it's possible to reach a small screwdrver into a narrow slot on the right side, and push down (toward the bottom of the camera, that is) the spring-loaded arm that's associated with the shutter cocking mechanism. This arm needs to be placed beneath the lever in the body that depresses it when the crank is wound. So, when repositioning the standard, you have to make sure you get the two posts set so that they will be engaged properly with the two levers for the meter and also have to hold tension on this arm.
Then, when replacing the bezel, insure that the interior aperture and shutter speed rings are set to f/3.5 and B respectively, and that the wheels on the bezel are set to the same values. There's a tab for the aperture and a pin for shutter speeds that must fit into their appropriate recesses. It took me a couple of tries, but I was able to hold the bezel in place and double check that both wheels were operating properly before replacing the five screws.
Because the front leatherette is now in tatters, I'm in need of a new piece. I found a site -- cameraleather.com that has a variety of replacement sets for this and many other cameras. Even though I only need the front piece, I guess I'll go ahead and order the whole set. Maybe I'll get one in one of the wild colors they offer 
Michael |
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