Canon LTM Winding knob on Canon 7

Canon M39 M39 screw mount bodies/lenses

traveler_101

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I acquired a Canon 7 a couple of years ago and have put a few rolls through it without problems. I like the camera. Today I started having trouble with the winding knob, specifically became it harder and harder to move it when rewinding the film; there was so much pressure on the knob that it finally it came loose from the shaft and I was forced to open the camera in the darkroom to remove the exposed film. Subsequently I reattached the knob - and it seems to work, though I haven't put in another roll. I noticed also playing around with it that it is increasingly difficult to lift and lower the knob as one is required to do to remove and load film. Is this a matter of lubrication that could be done without taking the camera apart? Anyone know?
 
Does the rewind knob turn freely with the film out?

This is a direct shaft, not geared as in a Nikon SP or Leica. There is a spring mechanism of some sort (been 10+ years since I took one apart) to hold the knob in place. If that is the problem- should be a problem with or without film. If the problem is only when film is loaded- I would expect the release for the wind mechanism.
 
Hi, thank you. Yes it moves freely now with the film out, keeping in mind that the knob had become detached from the shaft. After I got the film out I screwed it back in by holding the bottom of the shaft with a pair of pliers and tightening the knob. I thought about the release mechanism and set and reset it to the R position 3-4 times when rewinding the film with no positive effect. Just now that you mention it again I have checked it, and set in the R position it permits rewinding. Is it supposed to be completely free moving because it does have some tension of the take up reel.
 
There is some residual tension on the take up spool.

How many exposures on the roll- 12, 24, or 36? You might try a roll of 24 next time, see what happens. You may need to sacrifice a roll to test the camera, rewind with the back open.
 
Umm. Not to point out the obvious or embarrass you but it sounds like you were winding the wrong direction, which is why the rewind came off.
 
There is some residual tension on the take up spool.

How many exposures on the roll- 12, 24, or 36? You might try a roll of 24 next time, see what happens. You may need to sacrifice a roll to test the camera, rewind with the back open.

Brian, it was a roll of 36 - which is all I have at present. I tend to use then for reasons of economy - though I would actually prefer 24 rolls. Anyway, there were a couple of other extraordinary bits in this episode, which might be clues. The first occurred around frame 30. I began to get tension and a kind of crunching as I ADVANCED the film. The film continued to advance without problem but with a little more resistance and with the noted sound. The second extraordinary aspect, occurred when I loaded the film onto the reel of my development tank. I noted that when pulling the film off of the roll it was more difficult than usual, i.e. there seemed to be greater than normal resistance coming from the film roll itself (?), which I taken out of the camera at that point.
Question: if I conduct the experiment you suggest, what would I be looking for in rewinding with the back open? Thank you for your help.
 
Umm. Not to point out the obvious or embarrass you but it sounds like you were winding the wrong direction, which is why the rewind came off.

Lol. Well I should say that I succeeded in rewinding about 90% of the length of the film - so I am not completely hopeless. At first it was just difficult to rewind, but it became increasingly so until finally I couldn't move the winding knob. At that point I probably did move it in the other direction trying to free it. I never experienced anything like this before.
 
Lol. Well I should say that I succeeded in rewinding about 90% of the length of the film - so I am not completely hopeless. At first it was just difficult to rewind, but it became increasingly so until finally I couldn't move the winding knob. At that point I probably did move it in the other direction trying to free it. I never experienced anything like this before.

Hehe I think PRJ is right though. Stuff like that happens... the human mind is a very buggy thing. IIRC it is a right hand thread, so turning it clockwise as one should would tighten it. Winding the wrong way will also wind the film into the cassette, but with more friction.
 
As you put the rewind lever in place you will see an arrow on it, indicating the direction to rewind the film. Does yours have this feature, and did you follow it?
 
As you put the rewind lever in place you will see an arrow on it, indicating the direction to rewind the film. Does yours have this feature, and did you follow it?

Yes it certainly has the arrow. No I didn't consciously look at it; that sort of thing is automatic with me. Checking the camera now I see that the arrow is in the same direction as I imagined it would be and also in the same direction as my IIIf - clockwise, which is much easier with the left hand than moving in the other direction. Still it is possible I went the wrong way which, according to retinax, would have still have wound the film on and then loosened the winding knob - if that is correct? I suppose the next thing to do is try another roll.
 
Rolls of 36 can get tight when finishing up- and the friction could have been from the cannister itself.
Try another roll.
 
I 2nd Sonnar Brian, maybe you just had a bad roll, a loaded badly said roll, or a combination of both.
Also, the rewind knob should move freely in either direction without film loaded. It is not coupled to the rewind release in any way. Only thing holding it in place at any given time is the hub of the film canister itself. The rewind release only decouples the sprocket wheel to allow free movement of the film for rewinding.
 
Rolls of 36 can get tight when finishing up- and the friction could have been from the cannister itself.
Try another roll.

I wondered if perhaps the roll was part of the problem. Will try another roll - low on film right now and facing an intense work schedule. Will report back.
 
I 2nd Sonnar Brian, maybe you just had a bad roll, a loaded badly said roll, or a combination of both.
Also, the rewind knob should move freely in either direction without film loaded. It is not coupled to the rewind release in any way. Only thing holding it in place at any given time is the hub of the film canister itself. The rewind release only decouples the sprocket wheel to allow free movement of the film for rewinding.

Thank you for the information. In that case I must say that the rewind knob, while moving without problem, does seem a little stiff, especially moving up and down. Anyway it is good to know that the problem does not appear to involve the inner workings of the camera.
 
Moving the rewind knob up and down will face resistance- there is a mechanism for holding the knob in place until pulled out.
 
If you were winding the wrong way then the film would still rewind as retinax mentioned. You would be bending the film back well over 90 degrees and as the canister filled that would create less and less space for the film to bend making it difficult to keep winding. I doubt it was the film canister unless you bulk loaded it. I've never had an issue with a regular roll of film.

It is normal for the rewind to be a bit stiff when you are pulling it up. I have a super gone through rebuilt Canon 7 and it takes more force to pull the rewind up than any other camera that I have that I can think of. Nothing to worry about.

Canon 7s are fantastic cameras. I am amazed that they go for so little these days.
 
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