Sanity check and possibly stupid disassembly question ...

[dmr]

First of all, I'm not sure if this should go here in the Canon forum or in the repair forum so please excuse me if I posted in the wrong place. 😱

Anyway, this has been an interesting weekend. 🙂 To summarize I've got a GIII with a shutter that does not fire and a stuck shutter speed ring.

I just borrowed a fairly nice spanner wrench kit, and I already have such things as jewelers screwdrivers, hemostats, needle nose, etc., as I do occasional jewelry making and repair.

This is my first attempt to disassemble and repair a camera, so I'm taking things slow and easy and I thought I should check to see if anyone here who has done this before can answer a maybe-stupid question.

I'm right now just trying to disassemble the thing enough to inspect and see what is going on, or not going on. I removed the large front spanner screw ring, then the front black plate with the lettering, then a thin flat plate. Nothing I can see in there is obviously jammed/broken/loose or anything. I then took off the spanner screw ring (is that the correct term) which holds the front lens element, shook out the lens element and carefully wrapped it in tissue for the time being. I can't really see much more in the front, and I don't see any more obvious things to be removed from the front.

Now, here's my question. From the exploded diagrams, it looks like the way to take apart further is to remove both the main top and bottom covers and then remove the whole front lens/shutter/focus/meter thing in one assembly.

Is this what I should be removing next or is there something I'm missing where you can do more of the disassembly from the front?

Any comments would be appreciated.

Thanks in advance, gang. 🙂

 

[Pherdinand]

dmr: there's a how-to-remove central element of the canonet lens thread posted i think by Jon Goodman in the repair forum section here. Anyway, that is a bit tricky - you have to drill two holes in the mount of the lens element you see next when removing the frontal one.

If you look between the collar of this element and the outer shell/shutter assembly, you'll see that the collar has two notches which are alomst impossible to reach. They are,in fact, impossible to reach with a spanner wrench, as Jon says. BUT, i managed to reach them with a set of very thin nose plyers. Needed quite some force to unscrew it but it worked out. But oyu have to be VERY careful doing this, if you don';t want to scratch the metal collar. I scratched it lightly - it's in the inside and does not interfere with its action, so i don't care about it.

After unscrewing it, you wiull get access to the shutter blades, AND, three screws will be revealed; removing them, the first three rings will come off blank ring+sh.speed ring+ asa speed dial). You will have partial access to the shutter at this moment.

To flush the shutter with ronsonol etc, you should remove however the back lens elements, otherwise you'll mess the glass up. You have to do this from the inside of the camera, openng the film door. It might get difficult - this step i did not make.

Do the above at your own risk - just as i did.

 

[dmr]

First of all, thanks to everybody who sent me links, repair hints, and war stories. I really appreciate it. 🙂

dmr: there's a how-to-remove central element of the canonet lens thread posted i think by Jon Goodman in the repair forum section here.

Thanks, I kinda remember these from scanning that area last week. I guess I should, as we sometimes say at work, RTFM, and yes, I know what it means, I've been around the block a few times. 🙂

Anyway, that is a bit tricky - you have to drill two holes in the mount of the lens element you see next when removing the frontal one.

Ok this makes sense now. That will be tonite's project. 🙂 I do have a Dremel tool and very-teensy bits, as I use it for such things as drilling holes in coins and even (non-precious) stones for jewelry. I've got fairly small fingers, a good steady hand, and very good close up vision, so really I'm confident about being able to do things like that. It's just that I haven't done this thing before, and I want to go slow and careful.

Do the above at your own risk - just as i did.

Oh yes, I understand this part. 🙂 Actually, I'm getting very fascinated by this whole thing, and even if this doesn't come out like I want it to, it will be worth it for the experience. 🙂

Thanks again, gang! 🙂

 

[kabkos]

The correct tool for removing the rear collar is a spanner wrench that looks similar to a thin walled pipe with 2 teeth to catch the collar. I made mine out of a socket wrench, good strong steel that is able to be machined very thin and still strong enough to unfasten the hold down ring. A similar tool is used for removing the shutter in the Kodak Retina series cameras.

karl

 

[dmr]

This is my second try to post this. 🙁 I had it almost all typed in and the stupid {deletia} peecee wigged out and I lost it. 🙁 I'm on the workstation now which is usually very stable. {knocking on wood}

Anyway, the saga continues, and it's been a very interesting couple of days. 🙂

a how-to-remove central element of the canonet lens thread posted ... you have to drill two holes in the mount of the lens element you see next when removing the frontal one.

Believe it or not, this went very smoothly. I started drilling the holes at an angle with the dremel on slow, then shifed vertical when the hole got going. The spanner gripped it just fine, and it really didn't take much effort to get it unscrewed.

The center lens came out in one piece, and it looks very clean and clear. I was not looking forward to the game of optical cement.

After unscrewing it, you wiull get access to the shutter blades, AND, three screws will be revealed

Uh-huh. The screws were partly coated with lacquer, and a bit of NPR on a Q-tip took care of that. They came out very easily with a jewelers phillips.

removing them, the first three rings will come off blank ring+sh.speed ring+ asa speed dial). You will have partial access to the shutter at this moment.

Yes, the 3 rings came off fine, and ... this gave me the first real insight into what was REALLY going on with the thing.

The black shutter speed ring has a long metal tab that goes inward a few layers into the machanism. I'm assuming that this tab is what really adjusts the speed of the actual shutter.

Well, this tab was bent, sideways, and it was obvious that more force was used than I ever did when I first got the thing. I used small pliers and very carefully bent it back until it was perpendicular. That tab is very stiff. It took a lot of effort to bend it back, so it looks like somebody really tried to get that thing to move against something that was stuck.

I'm getting the idea that the original problem was that the shutter was probably stuck from non-use, and that whoever had it tried to force the speed dial and bent the tab, making the problem worse.

Anyway ...

To flush the shutter with ronsonol etc, you should remove however the back lens elements, otherwise you'll mess the glass up. You have to do this from the inside of the camera, openng the film door. It might get difficult - this step i did not make.

I seem to remember reading that some people leave the rear lens element in place, and then clean it from the front with the shutter on B when it's done. I think I would like to try this method if possible, since I looked at the rear lens and I don't think the spanner will reach in there. I didn't try, I was getting tired so I kind of put it all away for another night. 🙂

Do the above at your own risk - just as i did.

And ... with the risks go the rewards. 🙂

A few more observations and questions here ... I think that the root problem is the shutter being stuck, most likely from non-use. My instinct tells me to try the Ronsonol flush next. Would the masses here agree?

I'm getting some conflicting advice as to what solvent to use. Ronsonol seems to be the consensus, but acetone and isopropyl alcohol have also been mentioned and suggested.

I know that acetone will attack many plastics, so I tend to agree that is not the best. I have it, but it's not screaming "use me" or anything. 🙂

I'm assuming that Ronsonol is petroleum based, and therefore I would think that it would be the best to moisturize and revitalize any dried grease or other petroleum lubricants.

Alcohol I always think of as being drying. Like what you might use to dry up oil or grease.

What do you people think regarding these two solvents? Or, is it really a toss-up? Maybe first a Ronsonol flush followed by an alcohol flush?

Another thing I did was to pull off both the top and bottom case covers, really just to look for things obviously broken/bent/missing/loose and such. I didn't find anything obvious.

One thing I did learn is when you take off the rewind crank, be sure to leave it extended at least a bit, otherwise it's very hard to open the back.

Any, thanks again for all of the comments and support here. 🙂

 

[Pherdinand]

Glad to hear the successful operations🙂
I'd say, do NOT use acetone for flushing the shutter. There still are plastic components inside. You want to keep them solid, at their place.
(I used acetone once for cleaning a shutter - i just dropped the whole shutter into acetone and ultrasonic bath'ed it, it worked. But it was a fifties all-metal compur shutter; even the paint on the outside was untouched.)
Isopropyl alcohol is not like ethanol. It does not dry out the things that fast, in my experience.

You gotta be very careful if you leave the lens element in. Maybe if you turn the whole camera upside down and inject the cleaning fluid with a syringe, it might be safe. Don't use too much. If the fluid, carrying the dissolved grease, flows on the lens, you are doomed.

Keep us updated🙂

 

[Pherdinand]

By the way, indeed the long thick lever goes deep into the shutter. It has a bend on the bottom so it's not too easy to get it out from there. But i guess you've oticed that🙂

Putting back the wires in their place is also somewhat tricky.

I used isopropyl alcohol (just a bit of it)once to make the APERTURE blades of the canonet work properly. It was succesful, still working great, BUT, while exercising it still wet, the shutter splashed some of the liquid onto the lens surface behind him. Had to clean it afterwards (with shutter-on-bulb).

 

[SolaresLarrave]

Annie (I remember your name b/c you mentioned it in some other thread), I'm here rooting for you!

Good luck! 😀

 

[dmr]

Annie (I remember your name b/c you mentioned it in some other thread)

LOL! Actually, the name is really Denise, but they call me Annie for short. 🙂 (Yeah, I know, go figure!) 🙂

I'm here rooting for you!

Good luck! 😀

Hey, I appreciate the cheering section! 🙂 I still don't know if I'll be a successful camera repair person or not, but I'm really having a good time finding out! 🙂

I did some more RTFM-ing on the web today in my spare time, and I'm feeling better about it. When I get some time tonight I'm going to carefully probe the shutter blades with a dental explorer (a bent pointed pick) and look a bit more before I try a Ronsonol bath or anything like that.

I'm >>REALLY<< glad I found the note that the MIDDLE spanner ring (or whatever it's properly called) is the one you remove to pull out the rear lens thing. I would think the outer one would be.

Thanks again, gang. 🙂