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Jackson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, July 23, 2004 - 11:24 pm: | 
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I recently purchased a Mamiya Sekor Deluxe with the f/1.5 lens. It's in great condition cosmetically, but it has a shutter problem (Copal SVE) that needs repair. Here's a picture of the camera.
The symptom is that the shutter release only causes a click in the shutter. The leaves jerk a little, but never open. However, after opening the camera, I have discovered that after the click, I can manually activate the leaves by pressing very lightly inward on their center. This causes the shutter to open, then to close after the prescribed period of time. In this way, I have tested all the shutter speeds, including the slowest (1 sec), and everything except the initial activation seems to be OK. Here's a picture of the camera in its current state of disassembly.
One more thing. Take a close look at the picture above and you'll see a small speck off to the right. That's actually a pin that fell out of the shutter sometime after I removed the cover plate. Here's a closeup of the pin, with a Q-Tip for comparison. I should add that the shutter problem has not changed since the pin fell out. Everything that worked before (like advance, cocking, timer, etc) still work.
I know this is a long shot, but does anyone recognize this pin as a part that might belong in the leaves? If not, does the symptom (pressing on the leaves to activate the sequence) ring any bells?
Thanks for any assistance on this! |
Jackson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, July 24, 2004 - 01:22 pm: |
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One more thing: If I wet the shutter with naptha or degreaser, the release operates normally. It trips every time on all speed settings. Is this possibly an indicator that the shutter needs lubrication, or is it likely to mean something is worn out?
Anyone know whether there's a parts diagram anywhere on the Web that shows the basic mechanisms inside a Copal shutter?
Thanks! |
Dan Mitchell
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, July 24, 2004 - 06:07 pm: |
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The pin is most likely for a click-stop mechanism on the shutter or aperture control. I'm not familiar with that camera, but look for a hole or post somewhere with a spring in it.
The main problem is oil or grease on the shutter blades. The naptha will thin out the contaminents and the shutter will work until the naptha dries. Don't put oil in it. You need to completely clean the blades. The best way is to disassemble the shutter completely. You will have to figure out how to get the shutter off the camera to do a full disassembly.
However, you may be able to get it going by repeatedly wiping the blades with a piece of tissue or paper towel dampened with naptha. Let the shutter get completely dry before concluding it is clean.
I have instructions on a MXV shutter here:
http://daniel.mitchell.name/cameras/copalmxv/copalmxv.html
The SVE is a little different, but disassembly on copal shutters is basically the same on all the models. |
Jackson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, July 24, 2004 - 10:05 pm: |
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Thanks, since posting this request I have located the placement of the pin. It's the detent for the speed cam. Also, you're absolutely correct about the shutter. After it dried overnight, it started working. It's not reliable yet, but I can tell the problem is almost certain to be exactly what you've suggested.
Unfortunately, I now have another problem. I decided to reassable the camera and tackle a different defect. The rangefinder on this was extremely dim, so a cleaning seemed to be in order. Using a Q-Tip and Windex, I promptly wiped off all the half-silvering (is that the correct term?) on the 45 degree glass plate directly in front of the eyepiece. So, now I've gone from dim to none. Have I killed the camera? |
Haig Hovaness
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, July 24, 2004 - 10:53 pm: |
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You are learning why the cost of restoring one of these classic rangefinders is greater than the replacement cost on eBay. You will have to replace the half-silvered mirror, since there is no way to renew the silvering. Edmund Scientific sells 50% half-silvered glass, or you can cannibalize another old RF camera. |
Jackson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, July 24, 2004 - 11:24 pm: |
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Dang, why didn't I read the threads here before opening up the top of the camera? Oh well, it was dim anyway, so I guess it had to go.
As for eBay, I definitely understand the concept. I design/build/restore vacuum tube audio amps, and the same principles apply.
Guess I need to decide whether I really love this particular camera enough to go through all this. It's probably a scarce model, but I don't care about that when I'm shooting. Its f/1.5 lens is only slightly faster than an Electro 35, and this thing weighs a ton. OTOH, the glass is perfect and the meter works. Also, shutter speeds range from 1 sec to 1/500, and it's calibrated to ASA 800. The most important thing, though, is that it's styled just like a mid-60s transistor radio. Maybe that's enough in itself.  |
Jim Brokaw
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 25, 2004 - 12:42 am: |
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Well, no vacuum tubes in it, anyway.
You need to replace the half-silvered mirror. The Edmund mirror mentioned here is expensive, but they seem to be the only readily available source of the thin half-silvered mirrors I've been able to track down. Cutting that thin glass is a bit tricky too, best to practice on some plain glass of similar thickness. I use plain white toilet tissue moistened with windex for cleaning inside rangefinders, and I am very careful around the half-silvered mirror... its OK to clean it on the un-silvered side, but you need to be -sure- you have that right! Ball up the tissue and hold it carefully with 'spring-shut' tweezers.
Your shutter woes sound like a classic case of dried lube and/or migrated oil or grease to the shutter leafs. For almost all leaf shutters you can run them entirely clean and dry without problems. I use naptha and a cotton swab to clean off the leafs, and flood-clean the shutter mechanism. This is best done with the whole shutter removed from the camera, but if you get all the glass out sometimes that's enough. I use 'canned air' to blow out the naptha, and leave it set for a day or so just to be sure its all dried out. |
Jackson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 25, 2004 - 09:00 am: |
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Thanks, I guess I have a pretty good idea at this point what needs to be done. Yes, the entire shutter should probably be removed so it can soak. Of course, the trick to that is removing the front leatherette intact, right? I had a bad experience a year ago with that on a Ricoh TLR. It was my first ever camera repair. The stuff wouldn't come off in one piece, no matter what I did. In fact, it came off in about a hundred little tiny pieces. So, I'm not so anxious to try that again. If the shutter doesn't clean up without being removed, I may abandon this one. Thanks to everyone for all the good insight! |
Jim Brokaw
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 25, 2004 - 11:39 pm: |
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Some people have suggested warming the leatherette with a hair dryer before trying to remove it, using a flat knife blade or X-acto blade to try to undercut it when removing it, and flooding under the lifted edge with naptha or alcohol to soften any adhesive. Still a messy job, and sometimes the 40+ year old plastic is just all dried out and will crumbly. Even Leicas do it... then the best thing is to remove it all and replace it with a good modern substitute, either real leather or a matching appearance modern leatherette. I've had some good success using leather from leather fashion jackets bought at the thrift store... for $5-10 you can get enough leather for several camera bodys. |
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