Canon LTM Canonet 28 - Stuck Shutter / Aperture

Canon M39 M39 screw mount bodies/lenses

Ole Nemitz

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Local time
8:16 PM
Joined
Aug 5, 2005
Messages
18
Hello,

I have been trying to fix an inherited Canonet 28 (the newer model that was produced from 1972 to 1976 according to the Canon website) for the last couple of days. This is only my second mechanical camera to repair, and I guess I need some advice.
I have tried searching google (that`s how I found this site) and this forum, but to no avail concerning my specific problem.

The shutter and/or Aperture blades seem to be stuck. I read Henry Taber`s guide on Favorite Classics to cleaning them, but didn`t get in through the back of the lens. Through the front was easier, since I already had the "special tool" to turn the front lens assembly (read: old scissors ;) ).

Well, on on to my question: My blades look different than those in his article or those I have found pictures or diagrams of (mostly not the exact same model). In my camera there are only two blades visible, not five as I expected. I will try to attach pics. Is this normal, or have the blades become dislodged somehow? How am I supposed to my lighter fluid between them?

Another stupid question: Shouldn`t there be to sets of blades? One for the aperture and one for the shutter or am I mistaken? Those visible from front and back have the same "pattern" (see pics) only mirrored left/right and if i prop the upper blade up a little with a needle, there is also a gap visible from behind. that`s why I suspect, they are actually the same blades...

I hope someone here has experience with these models and is willing to share.

Greetings from Germany,
Ole
 
Thanks for the quick reply! I will do so right away...

edit: I don`t think this camera has a selftimer, but probably that only means I haven`t found it yet ;)
 
OK, I applied Lighter fluid liberally, wiggled the blades with a toothpick, and worked the Film advance and shutter release. The upper blade started twitching more and more over time, but also, there was an increasing resistance to overcome when cranking the film advance lever. Then I could wind on without tripping the shutter release, and now the shutter won`t fire at all.

I suspect problems with the mechanical coupling between film advance and shutter. Because I actuated the Film advance so often something has bent or snapped out of place.

Off goes the top cover ...
 
update: the Leatherette was not no match for me... :)
I have located the problem. Please look at the pictures, otherwise I can`t explain it.

the central piece (red) has a small roll on its right side, that is pushed up by that bar (green) that comes from the right side. (The roll goes up that slope, when the shutter is cocked). When advancing the film lever now, the central piece needs a little help getting up. Either helping directly with pliers or by partially depressing the shutter release (blue assembly moves down) will do...

help me think, how can I improve this? which part is not behaving as it should?

edit: forgot to mention: the pics are in cocked position.
 
Ah, much better! Loosening the screw a little made the resistance dissappear. Just had to bend a little afterwards as to get the wind lever lock mechanism working again... Wow, you gotta love the internet!

now back to the shutter... second round of lighter liquid!
 
update: Today I got into her bottom...

... because a pin slipped out when turning the camera frontside down (In lack of a better term I`ll call it: Rangefinder-Coupling-Pin) and a TINY wheel that was on this pin dropped into the depth of the camera and found its way between to levers at the bottom. Of course I didn`t know this at first. The camera just jammed completely....

Lesson learned? I now know how a rangefinder is coupled to the focussing ring and put a piece of tape on the pin to keep it from falling out.

That was the fun side of today`s repairs, the not-so-fun side is: the shutter is still sticking. I applied Lighter fluid 2 or 3 times yesterday, this morning it was almost dry. The twintching is about 1 or 2 mm now, but it still is not opening. Today I flushed it again, we`ll see whether that helped... Can there be another problem with the shutter causing it to not open except sticky blades?
 
Yet another update (YAU): shutter still stuck.. I think it`s moving a little bit more now, but I might be imagining things. It still isn`t completely dry, so there is still hope.
Another day, another strange malfunction: I was working the shutter while watching TV, when I noticed, that sometimes after cocking the shutter won`t fire, because the green (in my previous picture) bar won`t move completely to the left. when holding the advance lever in the cocked position it will sometimes slowly inch its way to left for the last couple of millimeters. Sometimes it needs a little help. Not quite sure, what to do yet.
Still haven`t found the exact right bend of the "red part". From time to time, the overwind lock doesn`t work... minor problem. Question: The screw that holds it in place comes loose when actuating the winding mechanism over and over. If it is too tight on the other hand, the overwind lock won`t disengage, because the part can`t return to it`s clockwise position. hmm strange question, but you get my drift.

captainslack: Thanks for the link, I am REALLY itching to cover the Canonet in some stylish medium brown leather now...

Today`s good news: This forum got me hooked ALREADY. Today I went to a local flea market and got myself a Lubitel 2. Seemed to be working just fine, and besides a damaged winding knob looks quite nice. I think for 19 Euro you can`t go wrong... Gonna get some rollfilm and shoot a test roll first thing tomorrow. Does anybody know how to date these things? I narrowed it down to 1965-1976 already, serial number is: 014991

Can I post it in Camera and Coffee now?! ;-)
That`s it for now, a lot of text for so little progress...

Good night,
Ole
 
No Progress after three flushings. so I decided to open up the lens a little bit more. I managed to take the outer cover of (the one with the ASA settings on it) and there were my two shutter/aperture blades (I got it now: Just one set of blades...). Spent some time working out the mechanism, then started poking with my trusty toothpick.

I attached two pictures. The first one shows the location of the shutter blades (red arrows). They are more easily accessible, than I feared after I had read up on sticky Canonet shutters (The 28 seems to have little in common with its bigger siblings lenswise).

There is a spring loaded lever that is coupled directly to the two blades. Normally the tension of the spring opens the shutter when fired. I managed to open mine when I "helped" that poor little spring by pushing with a toothpick (green arrows first picture) and then tripping the shutter. ... OPENED!

BUT it didn`t "snap" open, I had to push all the way and then it stuck open and returned only slowly to closed position when cocking several times...
On the front there is a small pin sticking out (green second picture), that is the other arm of my lever and the connection to the shutter blades. You can manually open and close the shutter by moving it up and down with a pair of pliers. not yery easy or smoth to move. VERY STICKY!

OK! There is no mechanical malfuction, it seems to be a matter of cleaning. I wonder if I used the wrong lighter fluid and made things worse, the blades move like they`re dipped in honey...

Help, I need some cleaning tips!

the inner side of the rear lens also looks terrible. There were dots scattered around the perimeter of the glass (Is this how fungus looks? It reminded me of bacteria cultures...) Now after trying to clean it is completely smeared around and even worse :bang:

Again: I need some cleaning tips. The lighter fluid I used is called Centralin and should be ok for cleaning shutter blades, according to some limited google research. I am thankful for any hints.
 
I will try that as a last resort. I too believe it should be clean by now, but I`ve given the lighter fluid another try. I also heated the blades up with a hairdryer and they went really really smooth when pushing the lever I described above. Without help though they still are only twitching. As long as I see progress in the twitching I will stay on this route. Need to buy more lighter fluid, the first can is almost empty...
I would like to try some graphite powder, but all my attempts of removing the rear glass have failed so far.
 
just a quick update: haven`t had much time during the last week. flushed it once more, still doesn`t open, but returns to closed after manually opening smoothly. I think the blades are clean. When I find the time, I`m going to disassemble some more and try to see if replacing a spring will help... Can`t break a camera, that is already broken ;)
 
OK, question for those of you that have seen the insides of more than one Canonet (Yes, I`m looking at you greyhoundman)

Is this normal or falling damage ? The "shutterfrontcoverplate" seems to have big dent in it, which could explain the higher friction my blades are having.

Think this is repairable?
 
Thanks for the quick reply and sorry for molesting you... As I said a few posts up: Can`t break a broken camera ;-) I`ll see what I can do...
 
Oh ... my ... GOD !!!

It worked!!! Absolutely NO friction in the shutter mechanism now. Granted - It is still unattached to the rest of the camera, but it works so smooth now. I just have to keep on working it.

I unbent it with a hammer and a screwdriver in the end, damn I need better tools.

Reassembly won`t be easy. I had to cut some wires and take of a variable resistance slider plastic-thingy that was glued on. I hope I can put it back without the electronics being terribly misadjusted afterwards.

woohoo, what a great feeling!
 
Picked up a soldering iron once in 8th grade. Burned my finger twice in the same spot. Swore I'd never touch one again.
 
Did you manage to not solder again? I seem to be confronted with it again and again and again...

There must be a simpler way of connecting two wire ends.
 
grr the forum ate my longish post yesterday. Short version:

I reassembled it, changed the light seals and reskinned it with light brown leatherette.

I`m done, but not all problems were completely solved. The overwind lock screw comes loose after a while, because I seem to be missing a nut. It`s in Rick Olesons drawings, but could not be found in my camera. I can live with that. Just have to remember not to wind twice.
Some mechanical Problem makes the shutter trip imediately after winding every 20th or so frame. I located the problem, but was unable to fix it. I have the feeling it`s getting better on its own. I can live with that too, as this camera is a little too automatic for my taste it is only a "fun-camera" anyway.

I would like to know how you test a new camera. how do you check the RF alignment and what shots do you take on a testroll? Do you use transparency film to test the metering?

Thanks for your help,
Ole
 
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