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Message |
    
Damien Chavarria.
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, July 09, 2004 - 12:37 pm: | 
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Hi all,
I was recently given a Canon FTb that has a problem and I would like to try and fix it. The problem is the following:
When the shutter release is pressed, the first curtain travels all the way and the mirror goes up. The second curtain however, never moves and the mirror does not go down.
When I advance the film to next frame, the mirror goes down and the first cutain goes back to the initial position so the process can be repeated again.
It happens at all shutter speeds. I am not sure if it happens because something is stuck and if fixing it requires major disassembly or not.
Any help will be greatly appreciated. |
Ron Sinnott
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, July 12, 2004 - 06:31 pm: |
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Hello,
There is a possibility that a curtain bearing is worn. You can find out by removing bottom cover. The bearing that usually wears is visable without anymore disassembly. You will see a brass bushing the curtain roller spins in. If the bushing is egg shaped the bearing is shot. If it is round the thats not the problem. Maybe dry lubrications or tension is gone on second curtain.
Good Luck! |
Damien Chavarria
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 13, 2004 - 07:20 am: |
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Hi Ron,
Thank you very much for your anwser. I have removed the bottom cover and though English is not my mother tongue I think I've been able to find translations of what I'm supposed to be looking for.
I have uploaded a photo of my FTb with bottom cover removed here. I beleive what you mention is what I've circled in RED. If that is the case, then I think it looks very round and not egg shaped.
In the meantime I've looked at what happens both when I advance the film and when I release the shutter.
In that same image I just uploaded, I cicled in GREEN an area that has a black plastic cylinder with a little knob that I beleive is supposed to turn at some point and descibe an almost complete circle in the space that is cut for in in the camera's body.
That black plastic thing never turns however (neither during frame advance nor during shutter release) and I can't force it to turn (looks stuck).
Once the shutter has been pressed and the first curtain has traveled however and if I I try to mimic what would happen if that thing turned with my finger by dragging it across the path, I notice it would push back levers 1 and 2 (see text on the photo).
Pushing back those levers result in bringing the mirror down again and reopening the aperture on the lens which would be part of the normal process.
Anybody know if that area cicled in green on my image is supposed to turn at some point and if yes what could be preventing it from doing so?
Again, thank a lot to everybody for help.
Cheers,
--
Damien Chavarria. |
Ron
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 13, 2004 - 11:38 am: |
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Hi Damien,
Nice photo of your camera. Yes indeed the curtain bearing is in good shape.
Next question I would ask you, is the counter window in place? These sometimes come ungluded and fall inside the camera. Also check to see if hot shoe is loose. Another thing that happens is one of the screws will loosen and fall into a mechanism.
The black gear you have numbered 2 must be able to turn. It is tied into the second curtain. If it is locked up tight camera is not going to fire.
Probably either a screw or counter window is jammed in shutter mechanism. If you want to remove the top cover to explore drop me a note and I'll try and point you in the right direction.
Goos luck......Ron |
Damien Chavarria
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 13, 2004 - 12:35 pm: |
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Thank you Ron,
Yes the counter window is still glued on and also the hot shoe is perfectly secured.
I have actually removed the top cover yesterday and was able to unmount quite a few things gears and things, up to the point where I was able to unscrew the glass part under the pentaprism and clean it (while I was at it) and see the miror from above, but I didn't want to go further as it started to get tricky (and lots of wires haging around).
I was able to remount everything so I can probably do it again and disassemble further if needed but up to that point (many parts already) I didn't see anything jammed in any of the gears I unmounted.
Do I have to dig deeper inside the top part to access the curtains themselves?
Thanks again Ron, this is really helful.
--
Damien. |
Amir
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 23, 2004 - 02:02 pm: |
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I have just developed some pictures that I took this summer with our old FTb. Since I was testing this baby I wrote down each setting for each frame I shot. I found out that half of my pictures didnt came out at all because they have shutter speed higher then 1/30s. I have made some empty shots and realised that my other curtain falls immediately at higher speeds from 1/30s leaving film unlighted. My counter window is gone so it has probably fell down the mechanism. I have dissasembled upper metal covering but I couldn't find it. I have downloaded F-1 manual so I'll try tommorow to take down all this wheels and springs out. Thanks for the tip. |
