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Mamiya 55mm for C series TLR
Old 03-06-2017   #1
mich rassena
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Mamiya 55mm for C series TLR

Last week I made a silly mistake and bought this lens in as is condition sight unseen, no returns. Silly me, I'd bought from this vendor before, and didn't think it'd be this bad. I thought at most there would be sticky shutter blades to contend with. So here's the deal, the shutter fires fine, eventually. The shutter cocks, I trip the shutter which releases the cocking arm, then it halts about 4/5 of the way through its travel, and just eeks along for a literal second until the shutter finally fires. Except sometimes, it works normally, other times I have to move it along with my finger. I do have the shutter set to X-sync, and have tried moving the slider back and forth, but with no difference in behavior.

Does anyone know what the cause is, and will the lens have to be opened up to make it work?
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Old 03-06-2017   #2
Jake Mongey
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I had this on the exact same lens - The lever with the cocking knob was bent ever so slightly and would get stuck on the chassis. I would check that first. Also i would exercise it to see if you can just clear it by use which usually works with leaf shuttters
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Old 03-06-2017   #3
mich rassena
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Quote:
Originally Posted by Jake Mongey View Post
I had this on the exact same lens - The lever with the cocking knob was bent ever so slightly and would get stuck on the chassis. I would check that first. Also i would exercise it to see if you can just clear it by use which usually works with leaf shuttters
Had the same thought that it was bent, but I can't see anywhere the arm collides with the case on its way down. I'll keep working on it, perhaps it will get better on its own. I'd rather not open it up if I don't have to.

The other issue is perhaps related. The aperture dial is not smooth at all. I would call its motion "crusty", seems just really harsh feeling to turn it, though it's not particular tight or anything. I wonder if there's just a lot of dirt inside causing both issues.

Edit: Thanks for your response. It's really helpful you've had the same problem with the same lens.
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Old 03-06-2017   #4
Jake Mongey
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Quote:
Originally Posted by mich rassena View Post
Had the same thought that it was bent, but I can't see anywhere the arm collides with the case on its way down. I'll keep working on it, perhaps it will get better on its own. I'd rather not open it up if I don't have to.

The other issue is perhaps related. The aperture dial is not smooth at all. I would call its motion "crusty", seems just really harsh feeling to turn it, though it's not particular tight or anything. I wonder if there's just a lot of dirt inside causing both issues.

Edit: Thanks for your response. It's really helpful you've had the same problem with the same lens.
My lens` aperture is the same, Honestly DO NOT ATTEMPT a repair unless you're very good. I completely ended my 80mm sekor trying this. They are quite difficult to work with. Once again I would recommend excerisising all functions - once you get it running you'll be amazed by its quality
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Old 03-06-2017   #5
mich rassena
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Quote:
Originally Posted by Jake Mongey View Post
My lens` aperture is the same, Honestly DO NOT ATTEMPT a repair unless you're very good. I completely ended my 80mm sekor trying this. They are quite difficult to work with. Once again I would recommend excerisising all functions - once you get it running you'll be amazed by its quality
Thanks for the warning. I usually only work on stuff that is beyond hope, because I usually wreck it anyway. If I can't get it to behave I'll just sell it off with a full disclosure of its problems to someone who'll hopefully have more luck/skill/money to fix it.
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Old 03-06-2017   #6
rick oleson
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It sounds like dirt in the shutter to me. Yes, it does have to be opened up, but it's a very conventional shutter and any old time repair shop should have no trouble with it. Biggest issue that I've had with Mamiya C series lenses is that the front elements are screwed on TIGHT and can be very hard to get off so that you can open the shutter. Once you're past that it's pretty straightforward.
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Old 03-06-2017   #7
Sarcophilus Harrisii
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Quote:
Originally Posted by mich rassena View Post
Last week I made a silly mistake and bought this lens in as is condition sight unseen, no returns. Silly me, I'd bought from this vendor before, and didn't think it'd be this bad. I thought at most there would be sticky shutter blades to contend with. So here's the deal, the shutter fires fine, eventually. The shutter cocks, I trip the shutter which releases the cocking arm, then it halts about 4/5 of the way through its travel, and just eeks along for a literal second until the shutter finally fires. Except sometimes, it works normally, other times I have to move it along with my finger. I do have the shutter set to X-sync, and have tried moving the slider back and forth, but with no difference in behavior.

Does anyone know what the cause is, and will the lens have to be opened up to make it work?
From whom and via what means did you buy the lens? Was it an eBay purchase? If so, your return options may not be as limited as you seem to think if the condition of the item does not match the listing description.
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Old 03-07-2017   #8
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Quote:
Originally Posted by Sarcophilus Harrisii View Post
From whom and via what means did you buy the lens? Was it an eBay purchase? If so, your return options may not be as limited as you seem to think if the condition of the item does not match the listing description.
Not an eBay purchase. I bought it knowing it was non-working, with a no return policy, so it's not a problem. I didn't pay a whole lot for it.
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Old 03-07-2017   #9
mich rassena
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Quote:
Originally Posted by rick oleson View Post
It sounds like dirt in the shutter to me. Yes, it does have to be opened up, but it's a very conventional shutter and any old time repair shop should have no trouble with it. Biggest issue that I've had with Mamiya C series lenses is that the front elements are screwed on TIGHT and can be very hard to get off so that you can open the shutter. Once you're past that it's pretty straightforward.
Last night I unscrewed the front element, looked around and didn't see any dust, moved the stiff aperture dial (It was more stiff than I had remembered) and tried the shutter a few times and for whatever reason, it started working properly. I put the front element on again and it still works. I'll try again this evening to see if it has reverted to its previous behavior.

Hopefully it'll just work and I can actually use it soon.
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Old 03-07-2017   #10
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Just a caution on the aperture. Too much resistance and too much force, can cause the pins that the blades rotate on to come out. I wouldn't have a clue how to get them back in since they seem to be pressure fitted. At least that is true on Ibsor shutters, later ones may have a better and more robust method of keeping them in.
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Old 03-07-2017   #11
mich rassena
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Originally Posted by oftheherd View Post
Just a caution on the aperture. Too much resistance and too much force, can cause the pins that the blades rotate on to come out. I wouldn't have a clue how to get them back in since they seem to be pressure fitted. At least that is true on Ibsor shutters, later ones may have a better and more robust method of keeping them in.
Good to know. I'm not sure how much would be too much force, but I know the handle that moves the aperture is breaking off. I wonder if I could take one from another lens.
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Old 03-07-2017   #12
mike rosenlof
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I've had a couple of Mamiya TLR lenses act this way. Shutter service at my local camera repair put it right. He said there was a spider egg sack in one of them, the other was gummed up lubricant.
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