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Tyler Payne
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, November 07, 2005 - 10:41 pm: | 
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I recently acquired a Mamiya C3 with an extremely sticky shutter. It often fails to open until after a couple attempts at holding it open with the B setting, at which point it will work somewhat normally for a time. I'll have to buy another one, but this one need not be a total loss: I recently read in a camera repair manual (Ed Romney's) that it's possible to degrease a shutter by injecting the degreaser into the shutter through the slot used by the cocking lever. My questions are these: will this work so that the lens will be basically usable (doesn't have to be 100%.) What degreaser should I use for this that wouldn't harm the lens elements? Finally, since I would prefer not to have to open the shutter up, can I be confident that the shutter will continue to work well without relubing it afterwards? Thanks very much in advance.
-tyler |
Paolo Amedeo
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, November 08, 2005 - 07:55 am: |
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Hi Tyler,
First, in order to attempt any kind of cleaning / lubrication of the shutter you have to unscrew both the front and rear elements of the lens. Otherwise, you could end up with a mechanically somehow working shutter, but a completely unusable lens clogged with dirt and oil in it's inner part (ignoring the risks of destroying the cement gluing together the single lenses...
If you are interested in a shutter that makes "click" every time you release it, but not so much reliable for speeds and consistency, it could somehow work your approach, followed by spraying in some dry lube (i.e. graphite or, better Teflon).
However this means just calling for more and more troubles to come...
Probably, if you clean each shutter blade with lighter fluid wiping them with cotton swabs, you would remove already enough dirt to get it working again...
Otherwise, a far better approach would be to open at least the cover of the shutter (underneath the front element of the lens there is a either a small screw or a screw with a large head with a side cut out: unscrew the little screw / turn the large one a fraction of a turn, so that the edges of the cut-out will align with the inner edge of the ring where it is locate. At this point, the ring is free to rotate -something like 1/6 of a turn counter-clock-wise - and can be removed, showing all the elements of the shutter. If you are brave enough, you should better remove also the ring for the time dial. In the case you have a digital camera, I strongly recommend you taking pictures before each step.) and rinse the shutter directly.
Then you can apply, sparingly, some very light oil, like the one used for watches.
I bet that, after being properly serviced, this lens could serve you for many years to come!!!
Good luck!
Paolo |
rick oleson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, November 08, 2005 - 08:37 am: |
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Hi Tyler:
It's not that hard to take the front cover off of a shutter so that you can put the solvents where you need them and not just squirt them around randomly. I have sketches of the Mamiya shutters (they're about as simple as they come) that you're welcome to if you like. Squirting stuff into a shutter can work, but I'd only advise it in cases where the shutter is particularly difficult to get into, and the Mamiya is not one of those. |
Tyler Payne
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, November 08, 2005 - 04:58 pm: |
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Ok, thanks for the advice. I'm starting to think that I might be able to open it on my own. Paolo, I can't find any screws around the lens or shutter though, except ones that seem to hold the viewing lens onto the board. I think if I did this, I'd just focus on clearing the sticky stuff off the visible part of the blades using a q-tip. I'm not sure how complicated a job I can do. My biggest problem Looks like getting the front lens element off without scratching it. Does this lens have its elements cemented on, requiring a solvent to unscrew it? Will I need a spanner wrench, or will an automotive strap wrench or hose clamp do the job? Is there a place where I can get a decent spanner for $30 or less? Thanks again guys. |
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